Progress in color night vision

NARCIS (Netherlands)

Toet, A.; Hogervorst, M.A.

2012-01-01

We present an overview of our recent progress and the current state-of-the-art techniques of color image fusion for night vision applications. Inspired by previously developed color opponent fusing schemes, we initially developed a simple pixel-based false color-mapping scheme that yielded fused

The adaptive value of primate color vision for predator detection.

Science.gov (United States)

Pessoa, Daniel Marques Almeida; Maia, Rafael; de Albuquerque Ajuz, Rafael Cavalcanti; De Moraes, Pedro Zurvaino Palmeira Melo Rosa; Spyrides, Maria Helena Constantino; Pessoa, Valdir Filgueiras

2014-08-01

The complex evolution of primate color vision has puzzled biologists for decades. Primates are the only eutherian mammals that evolved an enhanced capacity for discriminating colors in the green-red part of the spectrum (trichromatism). However, while Old World primates present three types of cone pigments and are routinely trichromatic, most New World primates exhibit a color vision polymorphism, characterized by the occurrence of trichromatic and dichromatic females and obligatory dichromatic males. Even though this has stimulated a prolific line of inquiry, the selective forces and relative benefits influencing color vision evolution in primates are still under debate, with current explanations focusing almost exclusively at the advantages in finding food and detecting socio-sexual signals. Here, we evaluate a previously untested possibility, the adaptive value of primate color vision for predator detection. By combining color vision modeling data on New World and Old World primates, as well as behavioral information from human subjects, we demonstrate that primates exhibiting better color discrimination (trichromats) excel those displaying poorer color visions (dichromats) at detecting carnivoran predators against the green foliage background. The distribution of color vision found in extant anthropoid primates agrees with our results, and may be explained by the advantages of trichromats and dichromats in detecting predators and insects, respectively. © 2014 Wiley Periodicals, Inc.

Coevolution of coloration and colour vision?

Science.gov (United States)

Lind, Olle; Henze, Miriam J; Kelber, Almut; Osorio, Daniel

2017-07-05

The evolutionary relationship between signals and animal senses has broad significance, with potential consequences for speciation, and for the efficacy and honesty of biological communication. Here we outline current understanding of the diversity of colour vision in two contrasting groups: the phylogenetically conservative birds, and the more variable butterflies. Evidence for coevolution of colour signals and vision exists in both groups, but is limited to observations of phenotypic differences between visual systems, which might be correlated with coloration. Here, to illustrate how one might interpret the evolutionary significance of such differences, we used colour vision modelling based on an avian eye to evaluate the effects of variation in three key characters: photoreceptor spectral sensitivity, oil droplet pigmentation and the proportions of different photoreceptor types. The models predict that physiologically realistic changes in any one character will have little effect, but complementary shifts in all three can substantially affect discriminability of three types of natural spectra. These observations about the adaptive landscape of colour vision may help to explain the general conservatism of photoreceptor spectral sensitivities in birds. This approach can be extended to other types of eye and spectra to inform future work on coevolution of coloration and colour vision.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Author(s).

Schopenhauer on vision and the colors.

Science.gov (United States)

Crone, R A

1997-01-01

Arthur Schopenhauer (1788-1860) published his book, On Vision and the Colors in 1816. He started from Aristotle's linear color system and Goethe's three pairs of contrast colors. His work preceded Hering's theory of opponent colors but his path to insight was blocked by his anti-Newtonianism and his neo-Hellenistic attitude toward science. Because of his theory of the subjectivity of colors he was a forerunner of the psycho-physiological variant of neo-Kantianism.

Applications of color machine vision in the agricultural and food industries

Science.gov (United States)

Zhang, Min; Ludas, Laszlo I.; Morgan, Mark T.; Krutz, Gary W.; Precetti, Cyrille J.

1999-01-01

Color is an important factor in Agricultural and the Food Industry. Agricultural or prepared food products are often grade by producers and consumers using color parameters. Color is used to estimate maturity, sort produce for defects, but also perform genetic screenings or make an aesthetic judgement. The task of sorting produce following a color scale is very complex, requires special illumination and training. Also, this task cannot be performed for long durations without fatigue and loss of accuracy. This paper describes a machine vision system designed to perform color classification in real-time. Applications for sorting a variety of agricultural products are included: e.g. seeds, meat, baked goods, plant and wood.FIrst the theory of color classification of agricultural and biological materials is introduced. Then, some tools for classifier development are presented. Finally, the implementation of the algorithm on real-time image processing hardware and example applications for industry is described. This paper also presented an image analysis algorithm and a prototype machine vision system which was developed for industry. This system will automatically locate the surface of some plants using digital camera and predict information such as size, potential value and type of this plant. The algorithm developed will be feasible for real-time identification in an industrial environment.

Operational Assessment of Color Vision

Science.gov (United States)

2016-06-20

YN0Ve_jXBUC&pg=PR11&source=gbs_selected_page s&cad=2#v=onepage&q&f=false. 5. Jeffries BJ. Color - blindness : its dangers and its detection. Boston (MA...Brussels, Belgium. Neuilly-sur-Seine (France): NATO; 1972. AGARD-CP-99. 11. Monlux DJ, Finne HA, Stephens MB. Color blindness and military fitness...unlimited. STINFO COPY AFRL-SA-WP-TR-2016-0008 Operational Assessment of Color Vision Steve Wright, O.D.; James Gaska, Ph.D

Dynamic simulation of color blindness for studying color vision requirements in practice

NARCIS (Netherlands)

Lucassen, M.P.; Alferdinck, J.W.A.M.

2006-01-01

We report on a dynamic simulation of defective color vision. Using an RGB video camera connected to a PC or laptop, the captured and displayed RGB colors are translated by our software into modified RGB values that simulate the color appearance of a person with a color deficiency. Usually, the

Color Functionality Used in Visual Display for Occupational and Environmental Safety and Managing Color Vision Deficiency.

Science.gov (United States)

Ochiai, Nobuhisa; Kondo, Hiroyuki

2017-01-01

The effects of color perception are utilized in visual displays for the purpose of safety in the workplace and in daily life. These effects, generally known as color functionality, are divided into four classifications: visibility, legibility, conspicuity and discriminability. This article focuses on the relationship between the color functionality of color schemes used in visual displays for occupational and environmental safety and color vision deficiency (particularly congenital red-green color deficiency), a critical issue in ophthalmology, and examines the effects of color functionality on the perception of the color red in individuals with protan defects. Due to abrupt system reforms, current Japanese clinical ophthalmology finds itself in a situation where it is insufficiently prepared to handle congenital red-green color deficiencies. Indeed, occupational problems caused by color vision deficiencies have been almost completely neglected, and are an occupational safety and health concern that will need to be solved in the future. This report will present the guidelines for the color vision testing established by the British Health and Safety Executive (HSE), a pioneering example of a model meant to solve these problems. Issues relating to the creation of guidelines adapted to Japanese clinical ophthalmology will also be examined, and we will discuss ways to utilize color functionality used in visual displays for occupational and environmental safety to help manage color vision deficiency.

76 FR 37690 - CooperVision, Inc.; Filing of Color Additive Petitions

Science.gov (United States)

2011-06-28

... color additives are intended to be copolymerized with various monomers for use as colored contact lens.... FDA-2011-C-0344 and FDA-2011-C-0463] CooperVision, Inc.; Filing of Color Additive Petitions AGENCY... Administration (FDA) is announcing that CooperVision, Inc., has filed two petitions proposing that the color...

Can the Farnsworth D15 Color Vision Test Be Defeated through Practice?

Science.gov (United States)

Ng, Jason S; Liem, Sophia C

2018-05-01

This study suggests that it is possible for some patients with severe red-green color vision deficiency to do perfectly on the Farnsworth D15 test after practicing it. The Farnsworth D15 is a commonly used test to qualify people for certain occupations. For patients with color vision deficiency, there may be high motivation to try to pass the test through practice to gain entry into a particular occupation. There is no evidence in the literature on whether it is possible for patients to learn to pass the D15 test through practice. Ten subjects with inherited red-green color vision deficiency and 15 color-normal subjects enrolled in the study. All subjects had anomaloscope testing, color vision book tests, and a Farnsworth D15 at an initial visit. For the D15, the number of major crossovers was determined for each subject. Failing the D15 was determined as greater than 1 major crossover. Subjects with color vision deficiency practiced the D15 as long as desired to achieve a perfect score and then returned for a second visit for D15 testing. A paired t test was used to analyze the number of major crossovers at visit 1 versus visit 2. Color-normal subjects did not have any major crossovers. Subjects with color vision deficiency had significantly (P color vision deficiency, and this should be considered in certain cases where occupational entry is dependent on D15 testing.

Color vision deficiencies and the child's willingness for visual activity: preliminary research

Science.gov (United States)

Geniusz, Malwina; Szmigiel, Marta; Geniusz, Maciej

2017-09-01

After a few weeks a newborn baby can recognize high contrasts in colors like black and white. They reach full color vision at the age of circa six months. Matching colors is the next milestone. Most children can do it at the age of two. Good color vision is one of the factors which indicate proper development of a child. Presented research shows the correlation between color vision and visual activity. The color vision of a group of children aged 3-8 was examined with saturated Farnsworth D-15. Fransworth test was performed twice - in a standard version and in a magnetic version. The time of completing standard and magnetic tests was measured. Furthermore, parents of subjects answered questions checking the children's visual activity in 1 - 10 scale. Parents stated whether the child willingly watched books, colored coloring books, put puzzles or liked to play with blocks etc. The Fransworth D-15 test designed for color vision testing can be used to test younger children from the age of 3 years. These are preliminary studies which may be a useful tool for further, more accurate examination on a larger group of subjects.

Color vision deficiency compensation for Visual Processing Disorder using Hardy-Rand-Rittler test and color transformation

Science.gov (United States)

Balbin, Jessie R.; Pinugu, Jasmine Nadja J.; Bautista, Joshua Ian C.; Nebres, Pauline D.; Rey Hipolito, Cipriano M.; Santella, Jose Anthony A.

2017-06-01

Visual processing skill is used to gather visual information from environment however, there are cases that Visual Processing Disorder (VPD) occurs. The so called visual figure-ground discrimination is a type of VPD where color is one of the factors that contributes on this type. In line with this, color plays a vital role in everyday living, but individuals that have limited and inaccurate color perception suffers from Color Vision Deficiency (CVD) and still not aware on their case. To resolve this case, this study focuses on the design of KULAY, a Head-Mounted Display (HMD) device that can assess whether a user has a CVD or not thru the standard Hardy-Rand-Rittler (HRR) test. This test uses pattern recognition in order to evaluate the user. In addition, color vision deficiency simulation and color correction thru color transformation is also a concern of this research. This will enable people with normal color vision to know how color vision deficient perceives and vice-versa. For the accuracy of the simulated HRR assessment, its results were validated thru an actual assessment done by a doctor. Moreover, for the preciseness of color transformation, Structural Similarity Index Method (SSIM) was used to compare the simulated CVD images and the color corrected images to other reference sources. The output of the simulated HRR assessment and color transformation shows very promising results indicating effectiveness and efficiency of the study. Thus, due to its form factor and portability, this device is beneficial in the field of medicine and technology.

Color vision: introduction by the feature editors.

Science.gov (United States)

Buck, Steven L; Baraas, Rigmor; Lee, Barry B; Lindsey, Delwin T; Uchikawa, Keiji; Webster, Michael A; Werner, John S

2016-03-01

This feature issue of the Journal of the Optical Society of America A (JOSA A) reflects the basic and applied research interests of members of the color vision community. Most of the articles stem from presentations at the 23rd Biennial Symposium of the International Colour Vision Society (ICVS).

Individualization of 2D color maps for people with color vision deficiencies

KAUST Repository

Waldin, Nicholas; Bernhard, Matthias; Rautek, Peter; Viola, Ivan

2016-01-01

2D color maps are often used to visually encode complex data characteristics such as heat or height. The comprehension of color maps in visualization is affected by the display (e.g., a monitor) and the perceptual abilities of the viewer. People with color vision deficiencies, such as red-green blindness, face difficulties when using conventional color maps. We propose a novel method for adapting a color map to an individual person, by having the user sort lines extracted from a given color map.

Individualization of 2D color maps for people with color vision deficiencies

KAUST Repository

Waldin, Nicholas

2016-12-13

2D color maps are often used to visually encode complex data characteristics such as heat or height. The comprehension of color maps in visualization is affected by the display (e.g., a monitor) and the perceptual abilities of the viewer. People with color vision deficiencies, such as red-green blindness, face difficulties when using conventional color maps. We propose a novel method for adapting a color map to an individual person, by having the user sort lines extracted from a given color map.

Railroad signal color and orientation : effects of color blindness and criteria for color vision field tests

Science.gov (United States)

2015-03-01

This report concerns two issues: 1) whether color vision is necessary for locomotive crews who work on railroads where the signal system is either completely redundant with regard to signal color and signal orientation or the signal system only uses ...

Red-Green Color Vision Impairment in Duchenne Muscular Dystrophy

Science.gov (United States)

Costa, Marcelo Fernandes ; Oliveira, Andre Gustavo Fernandes ; Feitosa-Santana, Claudia ; Zatz, Mayana ; Ventura, Dora Fix 

2007-01-01

The present study evaluated the color vision of 44 patients with Duchenne muscular dystrophy (DMD) (mean age 14.8 years; SD 4.9) who were submitted to a battery of four different color tests: Cambridge Colour Test (CCT), Neitz Anomaloscope, Ishihara, and American Optical Hardy-Rand-Rittler (AO H-R-R). Patients were divided into two groups according to the region of deletion in the dystrophin gene: upstream of exon 30 (n=12) and downstream of exon 30 (n=32). The control group was composed of 70 age-matched healthy male subjects with no ophthalmological complaints. Of the patients with DMD, 47% (21/44) had a red-green color vision defect in the CCT, confirmed by the Neitz Anomaloscope with statistical agreement (P.05). Of the patients with deletion downstream of exon 30, 66% had a red-green color defect. No color defect was found in the patients with deletion upstream of exon 30. A negative correlation between the color thresholds and age was found for the controls and patients with DMD, suggesting a nonprogressive color defect. The percentage (66%) of patients with a red-green defect was significantly higher than the expected <10% for the normal male population (P<.001). In contrast, patients with DMD with deletion upstream of exon 30 had normal color vision. This color defect might be partially explained by a retina impairment related to dystrophin isoform Dp260. PMID:17503325

Screening for Congenital Color Vision Deficiency in Primary ...

African Journals Online (AJOL)

Methods: The teachers were randomly selected from 13 schools in Port Harcourt City (PHC) and given a six hours training workshop on vision disorders in children and congenital color vision screening. They were given a self administered pre and post test questionnaires before and after training respectively. Subsequently ...

Color Vision 2018: Introduction by the feature editors.

Science.gov (United States)

Buck, Steven L; Baraas, Rigmor; Kremers, Jan; Lindsey, Delwin T; Nascimento, Sérgio M C; Webster, Michael A; Werner, John S

2018-04-01

This feature issue of the Journal of the Optical Society of America A (JOSA A) reflects the basic and applied research interests of members of the color vision community. Most of the articles stem from presentations at the 24th Biennial Symposium of the International Colour Vision Society (ICVS).

Statistical and molecular analyses of evolutionary significance of red-green color vision and color blindness in vertebrates.

Science.gov (United States)

Yokoyama, Shozo; Takenaka, Naomi

2005-04-01

Red-green color vision is strongly suspected to enhance the survival of its possessors. Despite being red-green color blind, however, many species have successfully competed in nature, which brings into question the evolutionary advantage of achieving red-green color vision. Here, we propose a new method of identifying positive selection at individual amino acid sites with the premise that if positive Darwinian selection has driven the evolution of the protein under consideration, then it should be found mostly at the branches in the phylogenetic tree where its function had changed. The statistical and molecular methods have been applied to 29 visual pigments with the wavelengths of maximal absorption at approximately 510-540 nm (green- or middle wavelength-sensitive [MWS] pigments) and at approximately 560 nm (red- or long wavelength-sensitive [LWS] pigments), which are sampled from a diverse range of vertebrate species. The results show that the MWS pigments are positively selected through amino acid replacements S180A, Y277F, and T285A and that the LWS pigments have been subjected to strong evolutionary conservation. The fact that these positively selected M/LWS pigments are found not only in animals with red-green color vision but also in those with red-green color blindness strongly suggests that both red-green color vision and color blindness have undergone adaptive evolution independently in different species.

Functional vision loss: a diagnosis of exclusion.

Science.gov (United States)

Villegas, Rex B; Ilsen, Pauline F

2007-10-01

Most cases of visual acuity or visual field loss can be attributed to ocular pathology or ocular manifestations of systemic pathology. They can also occasionally be attributed to nonpathologic processes or malingering. Functional vision loss is any decrease in vision the origin of which cannot be attributed to a pathologic or structural abnormality. Two cases of functional vision loss are described. In the first, a 58-year-old man presented for a baseline eye examination for enrollment in a vision rehabilitation program. He reported bilateral blindness since a motor vehicle accident with head trauma 4 years prior. Entering visual acuity was "no light perception" in each eye. Ocular health examination was normal and the patient made frequent eye contact with the examiners. He was referred for neuroimaging and electrophysiologic testing. The second case was a 49-year-old man who presented with a long history of intermittent monocular diplopia. His medical history was significant for psycho-medical evaluations and a diagnosis of factitious disorder. Entering uncorrected visual acuities were 20/20 in each eye, but visual field testing found constriction. No abnormalities were found that could account for the monocular diplopia or visual field deficit. A diagnosis of functional vision loss secondary to factitious disorder was made. Functional vision loss is a diagnosis of exclusion. In the event of reduced vision in the context of a normal ocular health examination, all other pathology must be ruled out before making the diagnosis of functional vision loss. Evaluation must include auxiliary ophthalmologic testing, neuroimaging of the visual pathway, review of the medical history and lifestyle, and psychiatric evaluation. Comanagement with a psychiatrist is essential for patients with functional vision loss.

Molecular patterns of X chromosome-linked color vision genes among 134 menof European ancestry

International Nuclear Information System (INIS)

Drummond-Borg, M.; Deeb, S.S.; Motulsky, A.G.

1989-01-01

The authors used Southern blot hybridization to study X chromosome-linked color vision genes encoding the apoproteins of red and green visual pigments in 134 unselected Caucasian men. One hundred and thirteen individuals (84.3%) had a normal arrangement of their color vision pigment genes. All had one red pigment gene; the number of green pigment genes ranged from one to five with a mode of two. The frequency of molecular genotypes indicative of normal color vision (84.3%) was significantly lower than had been observed in previous studies of color vision phenotypes. Color vision defects can be due to deletions of red or green pigment genes or due to formation of hybrid genes comprising portions of both red and green pigment genes. Characteristic anomalous patterns were seen in 15 (11.2%) individuals: 7 (5.2%) had patterns characteristic of deuteranomaly, 2 (1.5%) had patterns characteristic of deuteranopia, and 6 (4.5%) had protan patterns. Previously undescribed hybrid gene patterns consisting of both green and red pigment gene fragments in addition to normal red and green genes were observed in another 6 individuals (4.5%). Thus, DNA testing detected anomalous color vision pigment genes at a higher frequency than expected from phenotypic color vision tests

Harnessing color vision for visual oximetry in central cyanosis.

Science.gov (United States)

Changizi, Mark; Rio, Kevin

2010-01-01

Central cyanosis refers to a bluish discoloration of the skin, lips, tongue, nails, and mucous membranes, and is due to poor arterial oxygenation. Although skin color is one of its characteristic properties, it has long been realized that by the time skin color signs become visible, oxygen saturation is dangerously low. Here we investigate the visibility of cyanosis in light of recent discoveries on what color vision evolved for in primates. We elucidate why low arterial oxygenation is visible at all, why it is perceived as blue, and why it can be so difficult to perceive. With a better understanding of the relationship between color vision and blood physiology, we suggest two simple techniques for greatly enhancing the clinician's ability to detect cyanosis and other clinical color changes. The first is called "skin-tone adaptation", wherein sheets, gowns, walls and other materials near a patient have a color close to that of the patient's skin, thereby optimizing a color-normal viewer's ability to sense skin color modulations. The second technique is called "biosensor color tabs", wherein adhesive tabs with a color matching the patient's skin tone are placed in several spots on the skin, and subsequent skin color changes have the effect of making the initially-invisible tabs change color, their hue and saturation indicating the direction and magnitude of the skin color shift.

Reexamination of Color Vision Standards, Part I: Status of Color Use in ATC Displays and Demography of Color-Deficit Controllers

National Research Council Canada - National Science Library

Xing, Jing; Schroeder, David J

2006-01-01

This report describes the status of color use in current air traffic control (ATC) displays. It represents the first step in an effort to reexamine the color vision standards for air traffic controllers...

Key Informant Perceptions of Vision Loss in Children and ...

African Journals Online (AJOL)

tulyasys

understand how vision can practically be assessed and how poor vision can affect a child, whether by limiting the ability to do activities of daily living or by limiting social interactions. In this group, there were some misconceptions regarding the use of color vision and the assessment of reading as a tool for vision assessment ...

Perioperative Vision Loss in Cervical Spinal Surgery.

Science.gov (United States)

Gabel, Brandon C; Lam, Arthur; Chapman, Jens R; Oskouian, Rod J; Nassr, Ahmad; Currier, Bradford L; Sebastian, Arjun S; Arnold, Paul M; Hamilton, Steven R; Fehlings, Michael G; Mroz, Thomas E; Riew, K Daniel

2017-04-01

Retrospective multicenter case series. To assess the rate of perioperative vision loss following cervical spinal surgery. Medical records for 17 625 patients from 21 high-volume surgical centers from the AOSpine North America Clinical Research Network who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, inclusive, were reviewed to identify occurrences of vision loss following surgery. Of the 17 625 patients in the registry, there were 13 946 patients assessed for the complication of blindness. There were 9591 cases that involved only anterior surgical approaches; the remaining 4355 cases were posterior and/or circumferential fusions. There were no cases of blindness or vision loss in the postoperative period reported during the sampling period. Perioperative vision loss following cervical spinal surgery is exceedingly rare.

75 FR 10808 - CIBA Vision Corp.; Withdrawal of Color Additive Petitions

Science.gov (United States)

2010-03-09

...) proposing that the color additive regulations be amended to provide for the safe use of Color Index (C.I... of Color Additives Exempt from Certification (21 CFR part 73) to provide for the safe use of C.I...) CIBA Vision Corp.; Withdrawal of Color Additive Petitions AGENCY: Food and Drug Administration, HHS...

Emergent risk factors associated with eyeball loss and ambulatory vision loss after globe injuries.

Science.gov (United States)

Hyun Lee, Seung; Ahn, Jae Kyoun

2010-07-01

The objective of this study was to evaluate risk factors associated with eyeball loss and ambulatory vision loss on emergent examination of patients with ocular trauma. We reviewed the medical records of 1,875 patients hospitalized in a single tertiary referral center between January 2003 and December 2007. Emergent examinations included a history of trauma, elapsed time between injury and hospital arrival, visible intraocular tissues, and initial visual acuity (VA) using a penlight. The main outcome measures were ocular survival and ambulatory vision survival (>20/200) at 1 year after trauma using univariate and multivariate regression analysis. The ocular trauma scores were significantly higher in open globe injuries than in closed globe injuries (p eyeball loss. Elapsed time more than 12 hours and visible intraocular tissues were the significant risk factors associated with ambulatory vision loss. The most powerful predictor of eyeball loss and ambulatory vision loss was eyeball rupture. In closed globe injuries, there were no significant risk factors of eyeball loss, whereas initial vision less than LP and the presence of relative afferent pupillary defect were the significant risk factors associated with ambulatory vision loss. An initial VA less than LP using a penlight, a history of golf ball injury, and elapsed time more than 12 hours between ocular trauma and hospital arrival were associated with eyeball loss and ambulatory vision loss. Physicians should bear these factors in mind so that they can more effectively counsel patients with such injuries.

Losses of functional opsin genes, short-wavelength cone photopigments, and color vision--a significant trend in the evolution of mammalian vision.

Science.gov (United States)

Jacobs, Gerald H

2013-03-01

All mammalian cone photopigments are derived from the operation of representatives from two opsin gene families (SWS1 and LWS in marsupial and eutherian mammals; SWS2 and LWS in monotremes), a process that produces cone pigments with respective peak sensitivities in the short and middle-to-long wavelengths. With the exception of a number of primate taxa, the modal pattern for mammals is to have two types of cone photopigment, one drawn from each of the gene families. In recent years, it has been discovered that the SWS1 opsin genes of a widely divergent collection of eutherian mammals have accumulated mutational changes that render them nonfunctional. This alteration reduces the retinal complements of these species to a single cone type, thus rendering ordinary color vision impossible. At present, several dozen species from five mammalian orders have been identified as falling into this category, but the total number of mammalian species that have lost short-wavelength cones in this way is certain to be much larger, perhaps reaching as high as 10% of all species. A number of circumstances that might be used to explain this widespread cone loss can be identified. Among these, the single consistent fact is that the species so affected are nocturnal or, if they are not technically nocturnal, they at least feature retinal organizations that are typically associated with that lifestyle. At the same time, however, there are many nocturnal mammals that retain functional short-wavelength cones. Nocturnality thus appears to set the stage for loss of functional SWS1 opsin genes in mammals, but it cannot be the sole circumstance.

Color Vision Deficiency and Color Blindness: An Introduction to the Problem.

Science.gov (United States)

Olsen, Mary Margaret; Harris, Kenneth R.

The paper examines issues concerned with the education and employment of individuals, primarily males, with color vision deficiency. After a brief introduction, the first chapter looks at adult problems such as employment areas in which the disability presents problems. The next chapter considers problems of children, noting the heavy use of color…

Postraumatic delayed loss of vision

International Nuclear Information System (INIS)

Partington, C.R.; Graves, V.B.; Ruetenacht, D.A.; Weinstein, J.M.; Strother, C.M.

1989-01-01

The imaging studies and clinical findings in 10 patients who suffered delayed vision loss beginning 1 day to 13 years after head trauma have been reviewed. Two different primary lesions could be identified: pseudoaneurysm of the internal carotid artery and carotid cavernous fistula. The pathologic changes associated with pseudoaneurysm included compression of the optic nerves and/or chiasm by arterial aneurysm and intracranial hematoma. Carotid cavernous fistula caused delayed vision loss by compression of the optic nerves and chiasm by saccular dilatation of the cavernous sinus and by abnormal orbital venous drainage with retinal venous stasis, retinal edema, and glaucoma

Visual search in the real world: Color vision deficiency affects peripheral guidance, but leaves foveal verification largely unaffected

Directory of Open Access Journals (Sweden)

Günter eKugler

2015-12-01

Full Text Available Background: People with color vision deficiencies report numerous limitations in daily life. However, they use basic color terms systematically and in a similar manner as people with people with normal color vision. We hypothesize that a possible explanation for this discrepancy between color perception and behavioral consequences might be found in the gaze behavior of people with color vision deficiency.Methods: A group of participants with color vision deficiencies and a control group performed several search tasks in a naturalistic setting on a lawn.Results: Search performance was similar in both groups in a color-unrelated search task as well as in a search for yellow targets. While searching for red targets, color vision deficient participants exhibited a strongly degraded performance. This was closely matched by the number of fixations on red objects shown by the two groups. Importantly, once they fixated a target, participants with color vision deficiencies exhibited only few identification errors. Conclusions: Participants with color vision deficiencies are not able to enhance their search for red targets on a (green lawn by an efficient guiding mechanism. The data indicate that the impaired guiding is the main influence on search performance, while foveal identification (verification largely unaffected.

Signatures of functional constraint at aye-aye opsin genes: the potential of adaptive color vision in a nocturnal primate.

Science.gov (United States)

Perry, George H; Martin, Robert D; Verrelli, Brian C

2007-09-01

While color vision perception is thought to be adaptively correlated with foraging efficiency for diurnal mammals, those that forage exclusively at night may not need color vision nor have the capacity for it. Indeed, although the basic condition for mammals is dichromacy, diverse nocturnal mammals have only monochromatic vision, resulting from functional loss of the short-wavelength sensitive opsin gene. However, many nocturnal primates maintain intact two opsin genes and thus have dichromatic capacity. The evolutionary significance of this surprising observation has not yet been elucidated. We used a molecular population genetics approach to test evolutionary hypotheses for the two intact opsin genes of the fully nocturnal aye-aye (Daubentonia madagascariensis), a highly unusual and endangered Madagascar primate. No evidence of gene degradation in either opsin gene was observed for any of 8 aye-aye individuals examined. Furthermore, levels of nucleotide diversity for opsin gene functional sites were lower than those for 15 neutrally evolving intergenic regions (>25 kb in total), which is consistent with a history of purifying selection on aye-aye opsin genes. The most likely explanation for these findings is that dichromacy is advantageous for aye-ayes despite their nocturnal activity pattern. We speculate that dichromatic nocturnal primates may be able to perceive color while foraging under moonlight conditions, and suggest that behavioral and ecological comparisons among dichromatic and monochromatic nocturnal primates will help to elucidate the specific activities for which color vision perception is advantageous.

Prevalence of congenital color vision defects in Saudi females of Arab origin.

Science.gov (United States)

Alabdelmoneam, Mussaed

2011-09-01

Inherited color vision deficiencies (CVD) vary in prevalence by population and by sex. The most common CVD is X chromosome-linked anomalous trichromacy. Prevalence varies significantly by sex and race. The frequency of color vision defects in Saudi females has not been studied previously. This study surveyed the prevalence of congenital color vision defects in Saudi females of Arab origin. Seven thousand four hundred sixty-seven female subjects (N = 7,467) from the Kingdom of Saudi Arabia were screened using both Ishihara pseudoisochromatic plates and the Farnsworth Dichotomous test (D-15). CVD subjects were tested further with the Farnsworth-Munsell 100 Hue test. Of 7,467 female subjects tested, 26 subjects were found to have defective color vision, for a prevalence of 0.35%. Sixteen subjects had a deutan defect, and 10 had a protan defect. Arab females have significantly lower prevalence of CVD when compared with published data from females of other races. Analysis of the 5 regions of Saudi Arabia showed no significant difference between the regions. Prevalence of CVD among Saudi females of Arab origin is 0.35% and is among the lowest of all published data. Copyright © 2011 American Optometric Association. Published by Elsevier Inc. All rights reserved.

Comparison of a multispectral vision system and a colorimeter for the assessment of meat color

DEFF Research Database (Denmark)

Trinderup, Camilla Himmelstrup; Dahl, Anders Bjorholm; Jensen, Kirsten

2015-01-01

The color assessment ability of a multispectral vision system is investigated by a comparison study with color measurements from a traditional colorimeter. The experiment involves fresh and processed meat samples. Meat is a complex material; heterogeneous with varying scattering and reflectance...... are equally capable of measuring color. Moreover the vision system provides a more color rich assessment of fresh meat samples with a glossier surface, than the colorimeter. Careful studies of the different sources of variation enable an assessment of the order of magnitude of the variability between methods...... accounting for other sources of variation leading to the conclusion that color assessment using a multispectral vision system is superior to traditional colorimeter assessments. (C) 2014 Elsevier Ltd. All rights reserved....

Color vision abnormality as the sole manifestation of posterior reversible encephalopathy due to post-partum HELLP syndrome.

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Takahashi, Hironori; Matsubara, Teppei; Makino, Shinji; Horie, Kenji; Matsubara, Shigeki

2017-03-01

Posterior reversible encephalopathy syndrome (PRES) is associated with several symptoms; of those, visual acuity loss, light oversensitivity (photophobia), and light flashes (photopsia) are known as PRES-related eye symptoms. We report a post-partum woman with PRES associated with hemolysis, elevated liver enzymes, and low platelets syndrome (HELLP), in whom color vision abnormality (achromatopsia) was the sole manifestation. Cesarean section was performed at 28 weeks due to headache, epigastralgia, and severe hypertension. HELLP became evident after delivery. On post-partum day 1, she complained of achromatopsia, stating: "all things look brownish-gray". Ophthalmologic examination was normal, but brain magnetic resonance imaging showed occipital lobe lesions, indicative of PRES, and, interestingly, also color vision center (area V4) lesions, suggesting that the achromatopsia had been caused by brain damage. It may be prudent to question HELLP patients concerning achromatopsia. © 2017 Japan Society of Obstetrics and Gynecology.

Visual fields and eye morphology support color vision in a color-changing crab-spider.

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Insausti, Teresita C; Defrize, Jérémy; Lazzari, Claudio R; Casas, Jérôme

2012-03-01

Vision plays a major role in many spiders, being involved in prey hunting, orientation or substrate choice, among others. In Misumena vatia, which experiences morphological color changes, vision has been reported to be involved in substrate color matching. Electrophysiological evidence reveals that at least two types of photoreceptors are present in this species, but these data are not backed up by morphological evidence. This work analyzes the functional structure of the eyes of this spider and relates it to its color-changing abilities. A broad superposition of the visual field of the different eyes was observed, even between binocular regions of principal and secondary eyes. The frontal space is simultaneously analyzed by four eyes. This superposition supports the integration of the visual information provided by the different eye types. The mobile retina of the principal eyes of this spider is organized in three layers of three different types of rhabdoms. The third and deepest layer is composed by just one large rhabdom surrounded by dark screening pigments that limit the light entry. The three pairs of secondary eyes have all a single layer of rhabdoms. Our findings provide strong support for an involvement of the visual system in color matching in this spider. Copyright © 2011 Elsevier Ltd. All rights reserved.

Eye guidance during real-world scene search: The role color plays in central and peripheral vision.

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Nuthmann, Antje; Malcolm, George L

2016-01-01

The visual system utilizes environmental features to direct gaze efficiently when locating objects. While previous research has isolated various features' contributions to gaze guidance, these studies generally used sparse displays and did not investigate how features facilitated search as a function of their location on the visual field. The current study investigated how features across the visual field--particularly color--facilitate gaze guidance during real-world search. A gaze-contingent window followed participants' eye movements, restricting color information to specified regions. Scene images were presented in full color, with color in the periphery and gray in central vision or gray in the periphery and color in central vision, or in grayscale. Color conditions were crossed with a search cue manipulation, with the target cued either with a word label or an exact picture. Search times increased as color information in the scene decreased. A gaze-data based decomposition of search time revealed color-mediated effects on specific subprocesses of search. Color in peripheral vision facilitated target localization, whereas color in central vision facilitated target verification. Picture cues facilitated search, with the effects of cue specificity and scene color combining additively. When available, the visual system utilizes the environment's color information to facilitate different real-world visual search behaviors based on the location within the visual field.

Acute vision loss: a fuzzy presentation of sarcoidosis.

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Austin, Andrea L; Day, Luke T; Bishop, Frank M

2013-04-01

Acute vision loss is a devastating problem for patients and a challenging diagnostic dilemma for Emergency Physicians. This chief complaint is one in which we must be adept at quickly evaluating and initiating either care or referral. This case reviews the approach to acute vision loss and shows the importance of expanding the differential in atypical and complex presentations. A 31-year-old, previously healthy, white woman presented to the Emergency Department (ED) with 1 day of painless right eye vision loss. Ocular ultrasound and slit-lamp examination were unremarkable. Fundoscopic examination revealed retinal hemorrhages and papillitis. Her chest X-ray study was significant for bilateral hilar adenopathy, and subsequent lymph node biopsy confirmed the diagnosis of sarcoidosis. Although sarcoidosis is more common in African Americans, it must be considered in all patients in the appropriate clinical context. Sarcoidosis is an important diagnosis to include on the differential of many chief complaints that present to the ED, including acute vision loss and dyspnea. Published by Elsevier Inc.

Validity of the Worth 4 Dot Test in Patients with Red-Green Color Vision Defect.

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Bak, Eunoo; Yang, Hee Kyung; Hwang, Jeong-Min

2017-05-01

The Worth four dot test uses red and green glasses for binocular dissociation, and although it has been believed that patients with red-green color vision defects cannot accurately perform the Worth four dot test, this has not been validated. Therefore, the purpose of this study was to demonstrate the validity of the Worth four dot test in patients with congenital red-green color vision defects who have normal or abnormal binocular vision. A retrospective review of medical records was performed on 30 consecutive congenital red-green color vision defect patients who underwent the Worth four dot test. The type of color vision anomaly was determined by the Hardy Rand and Rittler (HRR) pseudoisochromatic plate test, Ishihara color test, anomaloscope, and/or the 100 hue test. All patients underwent a complete ophthalmologic examination. Binocular sensory status was evaluated with the Worth four dot test and Randot stereotest. The results were interpreted according to the presence of strabismus or amblyopia. Among the 30 patients, 24 had normal visual acuity without strabismus nor amblyopia and 6 patients had strabismus and/or amblyopia. The 24 patients without strabismus nor amblyopia all showed binocular fusional responses by seeing four dots of the Worth four dot test. Meanwhile, the six patients with strabismus or amblyopia showed various results of fusion, suppression, and diplopia. Congenital red-green color vision defect patients of different types and variable degree of binocularity could successfully perform the Worth four dot test. They showed reliable results that were in accordance with their estimated binocular sensory status.

Principles of image processing in machine vision systems for the color analysis of minerals

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Petukhova, Daria B.; Gorbunova, Elena V.; Chertov, Aleksandr N.; Korotaev, Valery V.

2014-09-01

At the moment color sorting method is one of promising methods of mineral raw materials enrichment. This method is based on registration of color differences between images of analyzed objects. As is generally known the problem with delimitation of close color tints when sorting low-contrast minerals is one of the main disadvantages of color sorting method. It is can be related with wrong choice of a color model and incomplete image processing in machine vision system for realizing color sorting algorithm. Another problem is a necessity of image processing features reconfiguration when changing the type of analyzed minerals. This is due to the fact that optical properties of mineral samples vary from one mineral deposit to another. Therefore searching for values of image processing features is non-trivial task. And this task doesn't always have an acceptable solution. In addition there are no uniform guidelines for determining criteria of mineral samples separation. It is assumed that the process of image processing features reconfiguration had to be made by machine learning. But in practice it's carried out by adjusting the operating parameters which are satisfactory for one specific enrichment task. This approach usually leads to the fact that machine vision system unable to estimate rapidly the concentration rate of analyzed mineral ore by using color sorting method. This paper presents the results of research aimed at addressing mentioned shortcomings in image processing organization for machine vision systems which are used to color sorting of mineral samples. The principles of color analysis for low-contrast minerals by using machine vision systems are also studied. In addition, a special processing algorithm for color images of mineral samples is developed. Mentioned algorithm allows you to determine automatically the criteria of mineral samples separation based on an analysis of representative mineral samples. Experimental studies of the proposed algorithm

[Colors and their meaning in culture and psychology--a historical outline and contemporary status of color vision theories].

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Grzybowski, Andrzej; Lewicka, Romana; Torlińska, Teresa; Stelcer, Bogusław

2008-01-01

The mechanism of color perception has intrigued scholars from antiquity. However, the understanding of this phenomena only came with the recognition of the nature of light and visual perception. Ancient concepts, present in science until the Renaissance, were based more on philosophical considerations and theoretical speculations than on anatomical studies and a matter-of-fact assessment of physiological functions of the visual system. From antiquity to 17th century scientific approach to the concept of vision was dominated by two theories: intromission and extramission (emanation). Intromission theory, propagated by Alhazen (lbn al.-Haythama), Vitello, John Peckham, Roger Bacon and Leonardo da Vinci, assumed that the light was transmitted from the observed object perpendicularly to the transparent eye structures. Johannes Kepler was the first scholar to propose that the retina was the receptive part of the eye. In the first half of the 17th century, Kepler's groundbreaking optical achievements and anatomical discoveries of many other scientists cast new light on the understanding of the role of different eye structures, finally wiping out the intromission theory. A further major achievement contributing to the recognition of the true nature of colors was a theory presented by Newton in 1688. He argued that they were colored rays, and not white light, that were composed of homogenous and pure light. It was, however, not until the 19th century when two modern theories of color appeared, i.e. a trichromatic theory mostly associated with the names of Young and Hemlholtz, and an opponent colors theory of Hering. In the 20th century, the two theories--previously assumed as contradictory--were joined into the zone theories of color vision. Colors have their cultural and social meanings, as far as a very individual and personal interpretation. In the former function they are used to illustrate some cultural and sociological phenomena; in the latter, they are helpful in

The organization of shape and color in vision and art.

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Pinna, Baingio

2011-01-01

The aim of this work is to study the phenomenal organization of shape and color in vision and art in terms of microgenesis of the object perception and creation. The idea of "microgenesis" is that the object perception and creation takes time to develop. Our hypothesis is that the roles of shape and color are extracted in sequential order and in the same order these roles are also used by artists to paint objects. Boundary contours are coded before color contours. The microgenesis of the object formation was demonstrated (i) by introducing new conditions derived from the watercolor illusion, where the juxtaposed contours are displaced horizontally or vertically, and based on variations of Matisse's Woman, (ii) by studying descriptions and replications of visual objects in adults and children of different ages, and (iii) by analyzing the linguistic sequence and organization in a free naming task of the attributes related to shape and color. The results supported the idea of the microgenesis of the object perception, namely the temporal order in the formation of the roles of the object properties (shape before color). Some general principles were extracted from the experimental results. They can be a starting point to explore a new domain focused on the microgenesis of shape and color within the more general problem of object organization, where integrated and multidisciplinary studies based on art and vision science can be very useful.

The organization of shape and color in Vision and Art

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Baingio ePinna

2011-10-01

Full Text Available The aim of this work is to study the phenomenal organization of shape and color in vision and art in terms of microgenesis of the object perception and creation. The idea of ‘microgenesis’ is that the object perception and creation takes time to develop. Our hypothesis is that the roles of shape and color are extracted in sequential order and in the same order these roles are also used by artists to paint objects. Boundary contours are coded before color contours. The microgenesis of the object formation was demonstrated (i by introducing new conditions derived from the watercolor illusion, where the juxtaposed contours are displaced horizontally or vertically, and based on variations of Matisse’s Woman, (ii by studying descriptions and replications of visual objects in adults and children of different ages, and (iii by analyzing the linguistic sequence and organization in a free naming task of the attributes related to shape and color. The results supported the idea of the microgenesis of the object perception, namely the temporal order in the formation of the roles of the object properties (shape before color. Some general principles were extracted from the experimental results. They can be a starting point to explore a new domain focused on the microgenesis of shape and color within the more general problem of object organization, where integrated and multidisciplinary studies based on art and vision science can be very useful.

Comparison of a multispectral vision system and a colorimeter for the assessment of meat color.

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Trinderup, Camilla H; Dahl, Anders; Jensen, Kirsten; Carstensen, Jens Michael; Conradsen, Knut

2015-04-01

The color assessment ability of a multispectral vision system is investigated by a comparison study with color measurements from a traditional colorimeter. The experiment involves fresh and processed meat samples. Meat is a complex material; heterogeneous with varying scattering and reflectance properties, so several factors can influence the instrumental assessment of meat color. In order to assess whether two methods are equivalent, the variation due to these factors must be taken into account. A statistical analysis was conducted and showed that on a calibration sheet the two instruments are equally capable of measuring color. Moreover the vision system provides a more color rich assessment of fresh meat samples with a glossier surface, than the colorimeter. Careful studies of the different sources of variation enable an assessment of the order of magnitude of the variability between methods accounting for other sources of variation leading to the conclusion that color assessment using a multispectral vision system is superior to traditional colorimeter assessments. Copyright © 2014 Elsevier Ltd. All rights reserved.

Acquired Color Vision Defects and Hexane Exposure: A Study of San Francisco Bay Area Automotive Mechanics.

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Beckman, Stella; Eisen, Ellen A; Bates, Michael N; Liu, Sa; Haegerstrom-Portnoy, Gunilla; Hammond, S Katharine

2016-06-01

Occupational exposure to solvents, including n-hexane, has been associated with acquired color vision defects. Blue-yellow defects are most common and may be due to neurotoxicity or retinal damage. Acetone may potentiate the neurotoxicity of n-hexane. We present results on nonhexane solvent and hexane exposure and color vision from a cross-sectional study of 835 automotive repair workers in the San Francisco Bay Area, California (2007-2013). Cumulative exposure was estimated from self-reported work history, and color vision was assessed using the Lanthony desaturated D-15 panel test. Log-binomial regression was used to estimate prevalence ratios for color vision defects. Acquired color vision defects were present in 29% of participants, of which 70% were blue-yellow. Elevated prevalence ratios were found for nonhexane solvent exposure, with a maximum of 1.31 (95% confidence interval (CI): 0.86, 2.00) for blue-yellow. Among participants aged ≤50 years, the prevalence ratio for blue-yellow defects was 2.17 (95% CI: 1.03, 4.56) in the highest quartile of nonhexane solvent exposure and 1.62 (95% CI: 0.97, 2.72) in the highest category of exposure to hexane with acetone coexposure. Cumulative exposures to hexane and nonhexane solvents in the highest exposure categories were associated with elevated prevalence ratios for color vision defects in younger participants. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Visual function and color vision in adults with Attention-Deficit/Hyperactivity Disorder.

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Kim, Soyeon; Chen, Samantha; Tannock, Rosemary

2014-01-01

Color vision and self-reported visual function in everyday life in young adults with Attention-Deficit/Hyperactivity Disorder (ADHD) were investigated. Participants were 30 young adults with ADHD and 30 controls matched for age and gender. They were tested individually and completed the Visual Activities Questionnaire (VAQ), Farnsworth-Munsell 100 Hue Test (FMT) and A Quick Test of Cognitive Speed (AQT). The ADHD group reported significantly more problems in 4 of 8 areas on the VAQ: depth perception, peripheral vision, visual search and visual processing speed. Further analyses of VAQ items revealed that the ADHD group endorsed more visual problems associated with driving than controls. Color perception difficulties on the FMT were restricted to the blue spectrum in the ADHD group. FMT and AQT results revealed slower processing of visual stimuli in the ADHD group. A comprehensive investigation of mechanisms underlying visual function and color vision in adults with ADHD is warranted, along with the potential impact of these visual problems on driving performance. Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

Medical student and patient perceptions of quality of life associated with vision loss.

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Chaudry, Imtiaz; Brown, Gary C; Brown, Melissa M

2015-06-01

Because most medical schools in the United States and Canada require no formal ophthalmology training, the authors queried medical student and ophthalmic patients to compare their perceptions of the quality of life (QOL) associated with vision loss. Cross-sectional comparative study of consecutive medical students and patients with vision loss using a validated, reliable, time trade-off utility instrument. Consecutive Jefferson Medical College medical students (cohort 1: 145 second-year student; cohort 2: 112 third-year/fourth-year students) and 283 patients with vision loss (patient cohort). Time trade-off vision utilities with anchors of 0.0 (death) to 1.0 (normal vision permanently) were used to quantify the QOL associated with vision loss. Students were asked to assume they had: (i) mild vision loss (20/40 to 20/50 vision in the better-seeing eye), (ii) legal blindness (20/200 in the better-seeing eye), and (iii) absolute blindness (no light perception bilaterally). Mean utilities for cohort 1/cohort 2 were 0.96/0.95 (p = 0.20) for mild vision loss, 0.88/0.84 for legal blindness (p = 0.009), and 0.80/0.67 (p student/patient mean utilities were 0.96/0.79 (p students underestimated the QOL associated with vision loss referent to patients with vision loss by 153%-425%. Medical students dramatically underestimated the impact of vision loss on patient QOL. Clinical training slightly improved medical student perceptions. Trivialization of vision loss could result in systemic health harm, less ophthalmic research dollars, loss of the finest medical students entering ophthalmology, and overall adverse financial effects for the field. Copyright © 2015. Published by Elsevier Inc.

The cost of vision loss in Canada. 2. Results.

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Cruess, Alan F; Gordon, Keith D; Bellan, Lorne; Mitchell, Scott; Pezzullo, M Lynne

2011-08-01

This study was conducted to provide the financial underpinnings necessary for effective planning for the provision of eye health services in Canada. Canada is facing an aging demographic and all the major eye diseases are diseases associated with aging. It is essential that we have information based on the best available data to support national and provincial vision health plans. The design associated with the prevalence-based approach used in this study was outlined previously in detail in The Cost of Vision Loss in Canada: Methodology. The methods associated with the prevalence-based approach used in this study were previously outlined in detail in The Cost of Vision Loss in Canada: Methodology. The financial cost of VL in Canada in 2007 was estimated to be $15.8 billion per annum: $8.6 billion (54.6%) represents direct health system expenditure; $4.4 billion (28.0%) was productivity lost due to lower employment, higher absenteeism, and premature death of Canadians with VL; $1.8 billion (11.1%) was the dead weight losses (DWL) from transfers including welfare payments and taxation forgone; $0.7 billion (4.4%) was the value of the care for people with VL; $305 million (1.9%) was other indirect costs such as aids and home modifications and the bring forward of funeral costs. Additionally, the value of the lost well-being (disability and premature death) was estimated at a further $11.7 billion. In per capita terms, this amounts to a financial cost of $19370 per person with VL per annum. Including the value of lost well-being, the cost is $33704 per person per annum. There is a growing awareness in Canada and around the world of the impact of VL on health costs and on the economy in general. This awareness is supported by the growing number of independent studies on the cost of vision loss both nationally and globally. Because most of these studies are limited by the minimal amount of available data, the overall cost of vision loss is likely underestimated

Color vision tests comparison: Farnsworth D-15 versus Lanthony D-15

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Szmigiel, Marta; Geniusz, Malwina; Geniusz, Maciej K.

2017-09-01

Disorder of color vision in humans is the inability to perceive differences between some or all of the colors that are normally perceived by others. Color blindness is usually a birth defect, a genetically determined. For this reason it is much more common in men than women. This paper presents the results of the test FarnsworthD-15 and Lanthony D-15 on a group of volunteers, both adults and children. The study was conducted to compare the results of both tests.

Seeing the Light: Optics in Nature, Photography, Color, Vision, and Holography

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Falk, David R.; Brill, Dieter R.; Stork, David G.

1985-11-01

The most complete and lucid nonmathematical study of light available. Chapters are self-contained, making the book flexible and easy to read. Coverage includes such non-traditional topics as processes of vision and the eye, atmospherical optical phenomena, color perception and illusions, color in nature and in art, Kirilian photography, and holography. Includes experiments that can be carried out with simple equipment. Chapters contain optional advanced sections, and appendixes review the mathematics for quantitative aspects. Illustrated, including a four-color insert.

Color vision abnormality as an initial presentation of the complete type of congenital stationary night blindness

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Tan X

2013-08-01

Full Text Available Xue Tan, Aya Aoki, Yasuo YanagiDepartment of Ophthalmology, University of Tokyo School of Medicine, Hongo, Bunkyo-ku, Tokyo, JapanAbstract: Patients with the complete form of congenital stationary night blindness (CSNB often have reduced visual acuity, myopia, impaired night vision, and sometimes nystagmus and strabismus, however, they seldom complain of color vision abnormality. A 17-year-old male who was at technical school showed abnormalities in the color perception test for employment, and was referred to our hospital for a detailed examination. He had no family history of color vision deficiency and no other symptoms. During the initial examination, his best-corrected visual acuity was 1.2 in both eyes. His fundus showed no abnormalities except for somewhat yellowish reflex in the fovea of both eyes. Electroretinogram (ERG showed a good response in cone ERG and 30 Hz flicker ERG, however, the bright flash, mixed rod and cone ERG showed a negative type with a reduced b-wave (positive deflection. There was no response in the rod ERG, either. From the findings of the typical ERG, the patient was diagnosed with complete congenital stationary night blindness. This case underscores the importance of ERG in order to diagnose the cause of a color vision anomaly.Keywords: congenital stationary night blindness, CSNB, electroretinogram, ERG, color vision defect

The evolution of opsins and color vision: connecting genotype to a complex phenotype

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Natasha I Bloch

2016-09-01

Full Text Available Dissecting the genetic basis of adaptive traits is key to our understanding of evolutionary processes. A major and essential step in the study of evolutionary genetics is drawing link between genotype and phenotype, which depends on the difficult process of defining the phenotype at different levels, from functional to organismal. Visual pigments are a key component of the visual system and their evolution could also provide important clues on the evolution of visual sensory system in response to sexual and natural selection. As a system in which genotype can be linked to phenotype, I will use visual pigments and color vision, particularly in birds, as a case of a complex phenotype. I aim to emphasize the difficulties in drawing the genotype-phenotype relationship for complex phenotypes and to highlight the challenges of doing so for color vision. The use of vision-based receiver models to quantify animal colors and patterns is increasingly important in many fields of evolutionary research, spanning studies of mate choice, predation, camouflage and sensory ecology. Given these models impact on evolution and ecology, it is important to provide other researchers with the opportunity to better understand animal vision and the corresponding advantages and limitations of these models.

Visual memory for objects following foveal vision loss.

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Geringswald, Franziska; Herbik, Anne; Hofmüller, Wolfram; Hoffmann, Michael B; Pollmann, Stefan

2015-09-01

Allocation of visual attention is crucial for encoding items into visual long-term memory. In free vision, attention is closely linked to the center of gaze, raising the question whether foveal vision loss entails suboptimal deployment of attention and subsequent impairment of object encoding. To investigate this question, we examined visual long-term memory for objects in patients suffering from foveal vision loss due to age-related macular degeneration. We measured patients' change detection sensitivity after a period of free scene exploration monocularly with their worse eye when possible, and under binocular vision, comparing sensitivity and eye movements to matched normal-sighted controls. A highly salient cue was used to capture attention to a nontarget location before a target change occurred in half of the trials, ensuring that change detection relied on memory. Patients' monocular and binocular sensitivity to object change was comparable to controls, even after more than 4 intervening fixations, and not significantly correlated with visual impairment. We conclude that extrafoveal vision suffices for efficient encoding into visual long-term memory. (c) 2015 APA, all rights reserved).

Accessible maps for the color vision deficient observers: past and present knowledge and future possibilities

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Kvitle, Anne Kristin

2018-05-01

Color is part of the visual variables in map, serving an aesthetic part and as a guide of attention. Impaired color vision affects the ability to distinguish colors, which makes the task of decoding the map colors difficult. Map reading is reported as a challenging task for these observers, especially when the size of stimuli is small. The aim of this study is to review existing methods for map design for color vision deficient users. A systematic review of research literature and case studies of map design for CVD observers has been conducted in order to give an overview of current knowledge and future research challenges. In addition, relevant research on simulations of CVD and color image enhancement for these observers from other fields of industry is included. The study identified two main approaches: pre-processing by using accessible colors and post-processing by using enhancement methods. Some of the methods may be applied for maps, but requires tailoring of test images according to map types.

Assessment of Color Vision Among School Children: A Comparative Study Between The Ishihara Test and The Farnsworth D-15 Test

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Rajesh Kishor Shrestha

2016-10-01

Full Text Available Introduction: Color vision is one of the important attribute of visual perception. The study was conducted at different schools of Kathmandu to compare the  ndings of the Ishihara Pseudoisochromatic test and the Farnsworth D-15 test.  Method: A cross-sectional study was conducted among 2120 students of four schools of Kathmandu. Assessment included visual acuity measurement, slit lamp examination of anterior segment and fundus examination with direct ophthalmoscopy. Each student was assessed with the Ishihara pseudoisochromatic test and the Farnsworth D-15 test. The Chi-square test was performed to analyse color vision defect detected by the Ishihara test and the Farnsworth D-15 test. Results: A total of 2120 students comprising of 1114 males (52.5% and 1006 females (47.5% were recruited in the study with mean age of 12.2 years (SD 2.3 years. The prevalence of color vision defect as indicated by the Ishihara was 2.6 and as indicated by the D-15 test was 2.15 in males.  Conclusion: For school color vision screening, the Ishihara color test and the Farnsworth D-15 test have equal capacity to detect congenital color vision defect and they complement each other.  Keywords: color vision; children; defect; Farnsworth D-15; Ishihara.

Color vision abnormality as an initial presentation of the complete type of congenital stationary night blindness.

Science.gov (United States)

Tan, Xue; Aoki, Aya; Yanagi, Yasuo

2013-01-01

Patients with the complete form of congenital stationary night blindness (CSNB) often have reduced visual acuity, myopia, impaired night vision, and sometimes nystagmus and strabismus, however, they seldom complain of color vision abnormality. A 17-year-old male who was at technical school showed abnormalities in the color perception test for employment, and was referred to our hospital for a detailed examination. He had no family history of color vision deficiency and no other symptoms. During the initial examination, his best-corrected visual acuity was 1.2 in both eyes. His fundus showed no abnormalities except for somewhat yellowish reflex in the fovea of both eyes. Electroretinogram (ERG) showed a good response in cone ERG and 30 Hz flicker ERG, however, the bright flash, mixed rod and cone ERG showed a negative type with a reduced b-wave (positive deflection). There was no response in the rod ERG, either. From the findings of the typical ERG, the patient was diagnosed with complete congenital stationary night blindness. This case underscores the importance of ERG in order to diagnose the cause of a color vision anomaly.

Performance of Color Camera Machine Vision in Automated Furniture Rough Mill Systems

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D. Earl Kline; Agus Widoyoko; Janice K. Wiedenbeck; Philip A. Araman

1998-01-01

The objective of this study was to evaluate the performance of color camera machine vision for lumber processing in a furniture rough mill. The study used 134 red oak boards to compare the performance of automated gang-rip-first rough mill yield based on a prototype color camera lumber inspection system developed at Virginia Tech with both estimated optimum rough mill...

Visual Memory for Objects Following Foveal Vision Loss

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Geringswald, Franziska; Herbik, Anne; Hofmüller, Wolfram; Hoffmann, Michael B.; Pollmann, Stefan

2015-01-01

Allocation of visual attention is crucial for encoding items into visual long-term memory. In free vision, attention is closely linked to the center of gaze, raising the question whether foveal vision loss entails suboptimal deployment of attention and subsequent impairment of object encoding. To investigate this question, we examined visual…

Color vision predicts processing modes of goal activation during action cascading.

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Jongkees, Bryant J; Steenbergen, Laura; Colzato, Lorenza S

2017-09-01

One of the most important functions of cognitive control is action cascading: the ability to cope with multiple response options when confronted with various task goals. A recent study implicates a key role for dopamine (DA) in this process, suggesting higher D1 efficiency shifts the action cascading strategy toward a more serial processing mode, whereas higher D2 efficiency promotes a shift in the opposite direction by inducing a more parallel processing mode (Stock, Arning, Epplen, & Beste, 2014). Given that DA is found in high concentration in the retina and modulation of retinal DA release displays characteristics of D2-receptors (Peters, Schweibold, Przuntek, & Müller, 2000), color vision discrimination might serve as an index of D2 efficiency. We used color discrimination, assessed with the Lanthony Desaturated Panel D-15 test, to predict individual differences (N = 85) in a stop-change paradigm that provides a well-established measure of action cascading. In this task it is possible to calculate an individual slope value for each participant that estimates the degree of overlap in task goal activation. When the stopping process of a previous task goal has not finished at the time the change process toward a new task goal is initiated (parallel processing), the slope value becomes steeper. In case of less overlap (more serial processing), the slope value becomes flatter. As expected, participants showing better color vision were more prone to activate goals in a parallel manner as indicated by a steeper slope. Our findings suggest that color vision might represent a predictor of D2 efficiency and the predisposed processing mode of goal activation during action cascading. Copyright © 2017 Elsevier Ltd. All rights reserved.

Disseminated neurocysticercosis presenting as isolated acute monocular painless vision loss

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Gaurav M Kasundra

2014-01-01

Full Text Available Neurocysticercosis, the most common parasitic infection of the nervous system, is known to affect the brain, eyes, muscular tissues and subcutaneous tissues. However, it is very rare for patients with ocular cysts to have concomitant cerebral cysts. Also, the dominant clinical manifestation of patients with cerebral cysts is either seizures or headache. We report a patient who presented with acute monocular painless vision loss due to intraocular submacular cysticercosis, who on investigation had multiple cerebral parenchymal cysticercal cysts, but never had any seizures. Although such a vision loss after initiation of antiparasitic treatment has been mentioned previously, acute monocular vision loss as the presenting feature of ocular cysticercosis is rare. We present a brief review of literature along with this case report.

Validity of FAA-approved color vision tests for class II and class III aeromedical screening.

Science.gov (United States)

1993-09-01

All clinical color vision tests currently used in the medical examination of pilots were studied regarding validity for prediction of performance on practical tests of ability to discriminate the aviation signal colors, red, green, and white given un...

Prevalence of vision loss among hospital in-patients; a risk factor for falls?

Science.gov (United States)

Leat, Susan J; Zecevic, Aleksandra A; Keeling, Alexis; Hileeto, Denise; Labreche, Tammy; Brymer, Christopher

2018-01-01

Despite poor vision being a risk factor for falls, current hospital policies and practices often do not include a vision assessment at patient admission or in the hospital's incident reporting system when a fall occurs. Our purpose was to document the prevalence of vision loss in hospital general medicine units to increase awareness of poor vision as a potential risk factor for falls that occur within the hospital, and inform future preventative practice. This cross-sectional study took place in medicine units of an acute care hospital. Participants were adult in-patients. Visual acuity (VA), contrast sensitivity and stereoacuity were measured, and patients were screened for field loss, extinction and neglect. 115 participants took part (average age 67 ± 17, 48% female). Overall, 89% had a visual impairment defined as being outside the age-norms for one or more vision measure, 62% had low vision, and 36% had vision loss equivalent to legal blindness [VA equal to or poorer than 1.0 logMAR (6/60, 20/200) or ≥10x below age-norms]. There was a considerable discrepancy between the prevalence of low vision and the percentage of patients who reported an ocular diagnosis that would result in visual loss (30%). Ten patients fell during the study period, and of these 100% had visual impairment, 90% had low vision and 60% had vision loss equivalent to legal blindness, which compares to 58%, 22% and 9% for non-fallers. Similar high prevalences were found in those whose reason for admission to the hospital was a fall (92%, 63% and 33% respectively). Vision loss has a high prevalence among patients in hospital medicine units, and is higher still among those who fall. Since vision loss may be a contributing factor to falls that occur in hospitals, implementing an assessment of vision at hospital admission would be useful to alert staff to those patients who are at risk for falls due to poor vision, so that preventative measures can be applied. © 2017 The Authors Ophthalmic

Computer vision system in real-time for color determination on flat surface food

Directory of Open Access Journals (Sweden)

Erick Saldaña

2013-03-01

Full Text Available Artificial vision systems also known as computer vision are potent quality inspection tools, which can be applied in pattern recognition for fruits and vegetables analysis. The aim of this research was to design, implement and calibrate a new computer vision system (CVS in real-time for the color measurement on flat surface food. For this purpose was designed and implemented a device capable of performing this task (software and hardware, which consisted of two phases: a image acquisition and b image processing and analysis. Both the algorithm and the graphical interface (GUI were developed in Matlab. The CVS calibration was performed using a conventional colorimeter (Model CIEL* a* b*, where were estimated the errors of the color parameters: eL* = 5.001%, and ea* = 2.287%, and eb* = 4.314 % which ensure adequate and efficient automation application in industrial processes in the quality control in the food industry sector.

Computer vision system in real-time for color determination on flat surface food

Directory of Open Access Journals (Sweden)

Erick Saldaña

2013-01-01

Full Text Available Artificial vision systems also known as computer vision are potent quality inspection tools, which can be applied in pattern recognition for fruits and vegetables analysis. The aim of this research was to design, implement and calibrate a new computer vision system (CVS in real - time f or the color measurement on flat surface food. For this purpose was designed and implemented a device capable of performing this task (software and hardware, which consisted of two phases: a image acquisition and b image processing and analysis. Both th e algorithm and the graphical interface (GUI were developed in Matlab. The CVS calibration was performed using a conventional colorimeter (Model CIEL* a* b*, where were estimated the errors of the color parameters: e L* = 5.001%, and e a* = 2.287%, and e b* = 4.314 % which ensure adequate and efficient automation application in industrial processes in the quality control in the food industry sector.

Impact of congenital color vision defect on color‑related tasks among ...

African Journals Online (AJOL)

Aim: To assess the difficulties encountered by students with congenital color vision defects in daily living and school activities. Methods: A cross‑sectional descriptive study conducted among students of public secondary schools in Ibadan, Nigeria. Structured questionnaires were administered to all consenting students to ...

Profound vision loss impairs psychological well-being in young and middle-aged individuals.

Science.gov (United States)

Garcia, Giancarlo A; Khoshnevis, Matin; Gale, Jesse; Frousiakis, Starleen E; Hwang, Tiffany J; Poincenot, Lissa; Karanjia, Rustum; Baron, David; Sadun, Alfredo A

2017-01-01

The aim of this study was to evaluate the effects of profound vision loss on psychological well-being in adolescents, young adults, and middle-aged adults with regard to mood, interpersonal interactions, and career-related goals. In addition, we assessed the significance of the resources that may be used to enhance psychological well-being in cases of profound vision loss, and in particular, examined the utility of low vision aids and the role of the ophthalmologist as a provider of emotional support. A questionnaire was issued to individuals aged 13-65 years with profound vision loss resulting from Leber's hereditary optic neuropathy (LHON). Depression prevalence was evaluated with questions regarding major depressive disorder symptomatology. Participants appraised the effects of vision loss on their interpersonal interactions and career goals by providing an impact rating (IR) on a 21-point psychometric scale from -10 to +10. Social well-being index was defined as the average of interpersonal IR and career IR. Subjects were additionally asked about the use of low vision aids and sources of emotional support. A total of 103 participants (mean age =26.4±11.2 years at LHON diagnosis; mean ± standard deviation) completed the questionnaire. Nearly half (49.5%) met the depression criteria after vision loss. Negative impacts on interpersonal interactions (median IR = -5) and career goals (median IR = -6) were observed; both ratings were worse ( P negative interpersonal IR and career IR. Sixty-eight percent of subjects used electronic vision aids; controlling for age, social well-being index was higher among these individuals than for those who did not use electronic aids ( P =0.03). Over half of the participants (52.4%) asserted that they derived emotional support from their ophthalmologist. Profound vision loss in adolescents, young adults, and middle-aged adults is associated with significant negative psychological and psychosocial effects, which are influenced by

The Disunity of Color

OpenAIRE

Matthen, Mohan

1999-01-01

What is color? What is color vision? Most philosophers answer by reference to humans: to human color qualia, or to the environmental properties or "quality spaces" perceived by humans. It is argued, with reference to empirical findings concerning comparative color vision and the evolution of color vision, that all such attempts are mistaken. An adequate definition of color vision must eschew reference to its outputs in the human cognition and refer only to inputs: color vision consists in...

Preventing Vision Loss in Diabetes - Summary

Centers for Disease Control (CDC) Podcasts

2008-04-24

This podcast is for a professional audience and briefly discusses how to prevent vision loss in people with diabetes.  Created: 4/24/2008 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP), Division of Diabetes Translation (DDT), National Diabetes Education Program (NDEP).   Date Released: 6/4/2008.

Acute Vision Loss Following Endoscopic Sinus Surgery

Directory of Open Access Journals (Sweden)

Serena Byrd

2017-01-01

Full Text Available A 41-year-old female with a history of uterine cancer and Celiac and Raynaud’s Disease presented to our institution with frequent migraines and nasal congestion. She underwent functional endoscopic sinus surgery (FESS and experienced acute unilateral vision loss postoperatively. Rapid recognition of the etiology and effective treatment are paramount given the permanent and irreversible vision loss that can result. Arterial vasospasm following FESS is rare. Patients with autoimmune diseases have perhaps an increased risk for vasospasm secondary to an increased vasoreactive profile. We present the first documented case of nitroglycerin sublingual therapy to successfully treat ophthalmic artery vasospasm following FESS. Nitroglycerin sublingual therapy is a promising treatment for ophthalmic vasospasm secondary to its ability to cross the blood-ocular barrier, its rapid onset of action, and its ability to promote relaxation of vascular smooth muscle.

Qualitative evaluations and comparisons of six night-vision colorization methods

Science.gov (United States)

Zheng, Yufeng; Reese, Kristopher; Blasch, Erik; McManamon, Paul

2013-05-01

Current multispectral night vision (NV) colorization techniques can manipulate images to produce colorized images that closely resemble natural scenes. The colorized NV images can enhance human perception by improving observer object classification and reaction times especially for low light conditions. This paper focuses on the qualitative (subjective) evaluations and comparisons of six NV colorization methods. The multispectral images include visible (Red-Green- Blue), near infrared (NIR), and long wave infrared (LWIR) images. The six colorization methods are channel-based color fusion (CBCF), statistic matching (SM), histogram matching (HM), joint-histogram matching (JHM), statistic matching then joint-histogram matching (SM-JHM), and the lookup table (LUT). Four categries of quality measurements are used for the qualitative evaluations, which are contrast, detail, colorfulness, and overall quality. The score of each measurement is rated from 1 to 3 scale to represent low, average, and high quality, respectively. Specifically, high contrast (of rated score 3) means an adequate level of brightness and contrast. The high detail represents high clarity of detailed contents while maintaining low artifacts. The high colorfulness preserves more natural colors (i.e., closely resembles the daylight image). Overall quality is determined from the NV image compared to the reference image. Nine sets of multispectral NV images were used in our experiments. For each set, the six colorized NV images (produced from NIR and LWIR images) are concurrently presented to users along with the reference color (RGB) image (taken at daytime). A total of 67 subjects passed a screening test ("Ishihara Color Blindness Test") and were asked to evaluate the 9-set colorized images. The experimental results showed the quality order of colorization methods from the best to the worst: CBCF colorization and for quantitative evaluation using an objective metric such as objective evaluation index

The cost of vision loss in Canada. 1. Methodology.

Science.gov (United States)

Gordon, Keith D; Cruess, Alan F; Bellan, Lorne; Mitchell, Scott; Pezzullo, M Lynne

2011-08-01

This paper outlines the methodology used to estimate the cost of vision loss in Canada. The results of this study will be presented in a second paper. The cost of vision loss (VL) in Canada was estimated using a prevalence-based approach. This was done by estimating the number of people with VL in a base period (2007) and the costs associated with treating them. The cost estimates included direct health system expenditures on eye conditions that cause VL, as well as other indirect financial costs such as productivity losses. Estimates were also made of the value of the loss of healthy life, measured in Disability Adjusted Life Years or DALY's. To estimate the number of cases of VL in the population, epidemiological data on prevalence rates were applied to population data. The number of cases of VL was stratified by gender, age, ethnicity, severity and cause. The following sources were used for estimating prevalence: Population-based eye studies; Canadian Surveys; Canadian journal articles and research studies; and International Population Based Eye Studies. Direct health costs were obtained primarily from Health Canada and Canadian Institute for Health Information (CIHI) sources, while costs associated with productivity losses were based on employment information compiled by Statistics Canada and on economic theory of productivity loss. Costs related to vision rehabilitation (VR) were obtained from Canadian VR organizations. This study shows that it is possible to estimate the costs for VL for a country in the absence of ongoing local epidemiological studies. Copyright © 2011 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

Central and Peripheral Vision Loss Differentially Affects Contextual Cueing in Visual Search

Science.gov (United States)

Geringswald, Franziska; Pollmann, Stefan

2015-01-01

Visual search for targets in repeated displays is more efficient than search for the same targets in random distractor layouts. Previous work has shown that this contextual cueing is severely impaired under central vision loss. Here, we investigated whether central vision loss, simulated with gaze-contingent displays, prevents the incidental…

Is My World Getting Smaller? The Challenges of Living with Vision Loss

Science.gov (United States)

Berger, Sue

2012-01-01

Introduction: Vision loss influences both basic and instrumental activities of daily living. There is limited information, however, on the relationship between vision loss and leisure activities. The research presented here was part of a larger study that aimed to understand the importance of participation in leisure activities for those with…

Universal Design: Supporting Students with Color Vision Deficiency (CVD) in Medical Education

Science.gov (United States)

Meeks, Lisa M.; Jain, Neera R.; Herzer, Kurt R.

2016-01-01

Color Vision Deficiency (CVD) is a commonly occurring condition in the general population. For medical students, it has the potential to create unique challenges in the classroom and clinical environments. Few studies have provided medical educators with comprehensive recommendations to assist students with CVD. This article presents a focused…

Measurement of meat color using a computer vision system.

Science.gov (United States)

Girolami, Antonio; Napolitano, Fabio; Faraone, Daniela; Braghieri, Ada

2013-01-01

The limits of the colorimeter and a technique of image analysis in evaluating the color of beef, pork, and chicken were investigated. The Minolta CR-400 colorimeter and a computer vision system (CVS) were employed to measure colorimetric characteristics. To evaluate the chromatic fidelity of the image of the sample displayed on the monitor, a similarity test was carried out using a trained panel. The panelists found the digital images of the samples visualized on the monitor very similar to the actual ones (Pmeat sample and the sample image on the monitor in order to evaluate the similarity between them (test A). Moreover, the panelists were asked to evaluate the similarity between two colors, both generated by the software Adobe Photoshop CS3 one using the L, a and b values read by the colorimeter and the other obtained using the CVS (test B); which of the two colors was more similar to the sample visualized on the monitor was also assessed (test C). The panelists found the digital images very similar to the actual samples (Pcolors the panelists found significant differences between them (Pcolor of the sample on the monitor was more similar to the CVS generated color than to the colorimeter generated color. The differences between the values of the L, a, b, hue angle and chroma obtained with the CVS and the colorimeter were statistically significant (Pcolor of meat. Instead, the CVS method seemed to give valid measurements that reproduced a color very similar to the real one. Copyright © 2012 Elsevier Ltd. All rights reserved.

Intelligent Color Vision System for Ripeness Classification of Oil Palm Fresh Fruit Bunch

OpenAIRE

Fadilah, Norasyikin; Mohamad-Saleh, Junita; Halim, Zaini Abdul; Ibrahim, Haidi; Ali, Syed Salim Syed

2012-01-01

Ripeness classification of oil palm fresh fruit bunches (FFBs) during harvesting is important to ensure that they are harvested during optimum stage for maximum oil production. This paper presents the application of color vision for automated ripeness classification of oil palm FFB. Images of oil palm FFBs of type DxP Yangambi were collected and analyzed using digital image processing techniques. Then the color features were extracted from those images and used as the inputs for Artificial Ne...

Advances in understanding the molecular basis of the first steps in color vision

Science.gov (United States)

Hofmann, Lukas; Palczewski, Krzysztof

2015-01-01

Serving as one of our primary environmental inputs, vision is the most sophisticated sensory system in humans. Here, we present recent findings derived from energetics, genetics and physiology that provide a more advanced understanding of color perception in mammals. Energetics of cis–trans isomerization of 11-cis-retinal accounts for color perception in the narrow region of the electromagnetic spectrum and how human eyes can absorb light in the near infrared (IR) range. Structural homology models of visual pigments reveal complex interactions of the protein moieties with the light sensitive chromophore 11-cis-retinal and that certain color blinding mutations impair secondary structural elements of these G protein-coupled receptors (GPCRs). Finally, we identify unsolved critical aspects of color tuning that require future investigation. PMID:26187035

High-speed potato grading and quality inspection based on a color vision system

Science.gov (United States)

Noordam, Jacco C.; Otten, Gerwoud W.; Timmermans, Toine J. M.; van Zwol, Bauke H.

2000-03-01

A high-speed machine vision system for the quality inspection and grading of potatoes has been developed. The vision system grades potatoes on size, shape and external defects such as greening, mechanical damages, rhizoctonia, silver scab, common scab, cracks and growth cracks. A 3-CCD line-scan camera inspects the potatoes in flight as they pass under the camera. The use of mirrors to obtain a 360-degree view of the potato and the lack of product holders guarantee a full view of the potato. To achieve the required capacity of 12 tons/hour, 11 SHARC Digital Signal Processors perform the image processing and classification tasks. The total capacity of the system is about 50 potatoes/sec. The color segmentation procedure uses Linear Discriminant Analysis (LDA) in combination with a Mahalanobis distance classifier to classify the pixels. The procedure for the detection of misshapen potatoes uses a Fourier based shape classification technique. Features such as area, eccentricity and central moments are used to discriminate between similar colored defects. Experiments with red and yellow skin-colored potatoes have shown that the system is robust and consistent in its classification.

Effect of elimination of nitrogen and/or hypoxia or restricted visual environment on color vision and range of accommodation

Science.gov (United States)

Wolbarsht, M. L.; White, C. W.; Anderson, W. B., Jr.

1973-01-01

The effects upon range of accommodation and color vision of reduced atmospheric pressure, at partial and complete elimination of nitrogen, of hypoxia, and of exposure for varying periods of time to restricted visual environment, have been studied alone or in various combinations. Measurements were made on the electroretinogram, the electrooculogram, and the diameter of the retinal vessels as an indicator of blood flow to the retina at the time of total elimination of nitrogen. An objective method was used to test range of accommodation. In the color vision test the flicker colors of a Benham's top were matched with a colorimeter.

Patterns of functional vision loss in glaucoma determined with archetypal analysis

Science.gov (United States)

Elze, Tobias; Pasquale, Louis R.; Shen, Lucy Q.; Chen, Teresa C.; Wiggs, Janey L.; Bex, Peter J.

2015-01-01

Glaucoma is an optic neuropathy accompanied by vision loss which can be mapped by visual field (VF) testing revealing characteristic patterns related to the retinal nerve fibre layer anatomy. While detailed knowledge about these patterns is important to understand the anatomic and genetic aspects of glaucoma, current classification schemes are typically predominantly derived qualitatively. Here, we classify glaucomatous vision loss quantitatively by statistically learning prototypical patterns on the convex hull of the data space. In contrast to component-based approaches, this method emphasizes distinct aspects of the data and provides patterns that are easier to interpret for clinicians. Based on 13 231 reliable Humphrey VFs from a large clinical glaucoma practice, we identify an optimal solution with 17 glaucomatous vision loss prototypes which fit well with previously described qualitative patterns from a large clinical study. We illustrate relations of our patterns to retinal structure by a previously developed mathematical model. In contrast to the qualitative clinical approaches, our results can serve as a framework to quantify the various subtypes of glaucomatous visual field loss. PMID:25505132

Profound vision loss impairs psychological well-being in young and middle-aged individuals

Directory of Open Access Journals (Sweden)

Garcia GA

2017-02-01

Full Text Available Giancarlo A Garcia,1,2 Matin Khoshnevis,1,3 Jesse Gale,1,4 Starleen E Frousiakis,1,5 Tiffany J Hwang,1,6 Lissa Poincenot,1 Rustum Karanjia,1,7–9 David Baron,6 Alfredo A Sadun1,7 1Doheny Eye Institute, Los Angeles, CA, USA; 2University of California, Irvine School of Medicine, Irvine, CA, USA; 3Department of Ophthalmology, Temple University, Philadelphia, PA, USA; 4Wellington School of Medicine and Health Sciences, University of Otago, Wellington, NZ; 5Department of Ophthalmology, New York Medical College, Valhalla, NY, USA; 6Department of Psychiatry & The Behavioral Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; 7Doheny Eye Centers, Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles California, CA, USA; 8Department of Ophthalmology, University of Ottawa, Ottawa, ON, Canada; 9Ottawa Hospital Health Research Institute, Ottawa, ON, Canada Purpose: The aim of this study was to evaluate the effects of profound vision loss on psychological well-being in adolescents, young adults, and middle-aged adults with regard to mood, interpersonal interactions, and career-related goals. In addition, we assessed the significance of the resources that may be used to enhance psychological well-being in cases of profound vision loss, and in particular, examined the utility of low vision aids and the role of the ophthalmologist as a provider of emotional support.Methods: A questionnaire was issued to individuals aged 13–65 years with profound vision loss resulting from Leber’s hereditary optic neuropathy (LHON. Depression prevalence was evaluated with questions regarding major depressive disorder symptomatology. Participants appraised the effects of vision loss on their interpersonal interactions and career goals by providing an impact rating (IR on a 21-point psychometric scale from −10 to +10. Social well-being index was defined as the average of interpersonal IR and career IR

Role of vision loss, functional limitations and the supporting network in depression in a general population.

Science.gov (United States)

van Nispen, Ruth M A; Vreeken, Hilde L; Comijs, Hannie C; Deeg, Dorly J H; van Rens, Ger H M B

2016-02-01

Although the prevalence of depression in visually impaired older persons is high, the association between vision loss and depression seems to be influenced by factors other than visual impairment. In this study, the role of vision loss, functional limitations and social network characteristics in relation to depressive symptoms was investigated. Cross-sectional data (N = 1237) from the Longitudinal Aging Study Amsterdam were used to investigate the prevalence of depression (Center of Epidemiological Studies-Depression scale) within subgroups with increasing vision loss. In linear regression models, functional limitations and social network characteristics were examined as possible mediators in the association between vision loss and depression. Having a partner was considered to be a potential moderator. Although a significant linear trend was found in the presence of depressive symptoms with 14% in normally sighted, 23% in mild and 37% in severe vision loss (χ(2)(1) = 14.9; p depression. Mediators were functional limitations (p depression, a trend was found with increasing severity of vision loss, indicating the need for more attention in (mental) health care and low-vision rehabilitation. In the general older population, vision loss was not an independent determinant of depression but was mediated by functional limitations and social network size. Rather than receiving actual social support, the idea of having a social network to rely on when needed seemed to be associated with lower levels of depression. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Long-term occupational exposure to organic solvents affects color vision, contrast sensitivity and visual fields.

Directory of Open Access Journals (Sweden)

Thiago Leiros Costa

Full Text Available The purpose of this study was to evaluate the visual outcome of chronic occupational exposure to a mixture of organic solvents by measuring color discrimination, achromatic contrast sensitivity and visual fields in a group of gas station workers. We tested 25 workers (20 males and 25 controls with no history of chronic exposure to solvents (10 males. All participants had normal ophthalmologic exams. Subjects had worked in gas stations on an average of 9.6 ± 6.2 years. Color vision was evaluated with the Lanthony D15d and Cambridge Colour Test (CCT. Visual field assessment consisted of white-on-white 24-2 automatic perimetry (Humphrey II-750i. Contrast sensitivity was measured for sinusoidal gratings of 0.2, 0.5, 1.0, 2.0, 5.0, 10.0 and 20.0 cycles per degree (cpd. Results from both groups were compared using the Mann-Whitney U test. The number of errors in the D15d was higher for workers relative to controls (p<0.01. Their CCT color discrimination thresholds were elevated compared to the control group along the protan, deutan and tritan confusion axes (p<0.01, and their ellipse area and ellipticity were higher (p<0.01. Genetic analysis of subjects with very elevated color discrimination thresholds excluded congenital causes for the visual losses. Automated perimetry thresholds showed elevation in the 9°, 15° and 21° of eccentricity (p<0.01 and in MD and PSD indexes (p<0.01. Contrast sensitivity losses were found for all spatial frequencies measured (p<0.01 except for 0.5 cpd. Significant correlation was found between previous working years and deutan axis thresholds (rho = 0.59; p<0.05, indexes of the Lanthony D15d (rho=0.52; p<0.05, perimetry results in the fovea (rho= -0.51; p<0.05 and at 3, 9 and 15 degrees of eccentricity (rho= -0.46; p<0.05. Extensive and diffuse visual changes were found, suggesting that specific occupational limits should be created.

Heuristics in primary care for recognition of unreported vision loss in older people: a technology development study.

Science.gov (United States)

Wijeyekoon, Skanda; Kharicha, Kalpa; Iliffe, Steve

2015-09-01

To evaluate heuristics (rules of thumb) for recognition of undetected vision loss in older patients in primary care. Vision loss is associated with ageing, and its prevalence is increasing. Visual impairment has a broad impact on health, functioning and well-being. Unrecognised vision loss remains common, and screening interventions have yet to reduce its prevalence. An alternative approach is to enhance practitioners' skills in recognising undetected vision loss, by having a more detailed picture of those who are likely not to act on vision changes, report symptoms or have eye tests. This paper describes a qualitative technology development study to evaluate heuristics for recognition of undetected vision loss in older patients in primary care. Using a previous modelling study, two heuristics in the form of mnemonics were developed to aid pattern recognition and allow general practitioners to identify potential cases of unreported vision loss. These heuristics were then analysed with experts. Findings It was concluded that their implementation in modern general practice was unsuitable and an alternative solution should be sort.

[Ocular myositis as a rare cause of vision loss].

Science.gov (United States)

Rollnik, J D; Requadt, H

2017-04-01

Ocular myositis is a rare disease characterized by painful diplopia but loss of vision rarely occurs. The article reviews the literature focusing on the differential diagnostics. We report the case of an 80-year-old women suffering from slowly progressive loss of vision in the left eye. Diplopia was only present at the beginning and there was only moderate pain. Computed tomography and magnetic resonance imaging revealed a swelling of the left medial, lateral and inferior rectus muscles of the orbit leading to compression of the optic nerve in the orbital cone. An intravenous prednisolone stoss therapy (1000 mg per day for 3 consecutive days) was initiated, followed by oral medication of 100 mg per day then tapering over 10 weeks. Vision improved and no relapses were observed. Physicians should be aware of this rare disease to ensure quick diagnosis and treatment of ocular myositis.

Reduced Discrimination in the Tritanopic Confusion Line for Congenital Color Deficiency Adults.

Science.gov (United States)

Costa, Marcelo F; Goulart, Paulo R K; Barboni, Mirella T S; Ventura, Dora F

2016-01-01

In congenital color blindness the red-green discrimination is impaired resulting in an increased confusion between those colors with yellow. Our post-receptoral physiological mechanisms are organized in two pathways for color perception, a red-green (protanopic and deuteranopic) and a blue-yellow (tritanopic). We argue that the discrimination losses in the yellow area in congenital color vision deficiency subjects could generate a subtle loss of discriminability in the tritanopic channel considering discrepancies with yellow perception. We measured color discrimination thresholds for blue and yellow of tritanopic channel in congenital color deficiency subjects. Chromaticity thresholds were measured around a white background (0.1977 u', 0.4689 v' in the CIE 1976) consisting of a blue-white and white-yellow thresholds in a tritanopic color confusion line of 21 congenital colorblindness subjects (mean age = 27.7; SD = 5.6 years; 14 deuteranomalous and 7 protanomalous) and of 82 (mean age = 25.1; SD = 3.7 years) normal color vision subjects. Significant increase in the whole tritanopic axis was found for both deuteranomalous and protanomalous subjects compared to controls for the blue-white (F 2,100 = 18.80; p color confusion axis is significantly reduced in congenital color vision deficiency compared to normal subjects. Since yellow discrimination was impaired the balance of the blue-yellow channels is impaired justifying the increased thresholds found for blue-white discrimination. The weighting toward the yellow region of the color space with the deuteranomalous contributing to that perceptual distortion is discussed in terms of physiological mechanisms.

Gene loss, adaptive evolution and the co-evolution of plumage coloration genes with opsins in birds.

Science.gov (United States)

Borges, Rui; Khan, Imran; Johnson, Warren E; Gilbert, M Thomas P; Zhang, Guojie; Jarvis, Erich D; O'Brien, Stephen J; Antunes, Agostinho

2015-10-06

The wide range of complex photic systems observed in birds exemplifies one of their key evolutionary adaptions, a well-developed visual system. However, genomic approaches have yet to be used to disentangle the evolutionary mechanisms that govern evolution of avian visual systems. We performed comparative genomic analyses across 48 avian genomes that span extant bird phylogenetic diversity to assess evolutionary changes in the 17 representatives of the opsin gene family and five plumage coloration genes. Our analyses suggest modern birds have maintained a repertoire of up to 15 opsins. Synteny analyses indicate that PARA and PARIE pineal opsins were lost, probably in conjunction with the degeneration of the parietal organ. Eleven of the 15 avian opsins evolved in a non-neutral pattern, confirming the adaptive importance of vision in birds. Visual conopsins sw1, sw2 and lw evolved under negative selection, while the dim-light RH1 photopigment diversified. The evolutionary patterns of sw1 and of violet/ultraviolet sensitivity in birds suggest that avian ancestors had violet-sensitive vision. Additionally, we demonstrate an adaptive association between the RH2 opsin and the MC1R plumage color gene, suggesting that plumage coloration has been photic mediated. At the intra-avian level we observed some unique adaptive patterns. For example, barn owl showed early signs of pseudogenization in RH2, perhaps in response to nocturnal behavior, and penguins had amino acid deletions in RH2 sites responsible for the red shift and retinal binding. These patterns in the barn owl and penguins were convergent with adaptive strategies in nocturnal and aquatic mammals, respectively. We conclude that birds have evolved diverse opsin adaptations through gene loss, adaptive selection and coevolution with plumage coloration, and that differentiated selective patterns at the species level suggest novel photic pressures to influence evolutionary patterns of more-recent lineages.

Vision loss associated with the use and removal of intraocular silicone oil

Directory of Open Access Journals (Sweden)

Patrick D Williams

2009-02-01

Full Text Available Patrick D Williams1, Christopher G Fuller1, Ingrid U Scott2, Dwain G Fuller1, Harry W Flynn Jr31Texas Retina Associates, Dallas, TX, USA; 2Departments of Ophthalmology and Health Evaluation Sciences, Penn State College of Medicine, Hershey, PA, USA; 3Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USAPurpose: To describe vision loss associated with the use or removal of silicone oil retinal tamponade.Methods: Records were reviewed of all patients with a decrease in visual acuity of at least 3 Snellen lines from best acuity with 5000 centistoke silicone oil in place or after removal of silicone oil at a single retina-only practice between 1996 and 2006.Results: Nine patients (6 men, 3 women with a mean age of 48 years (range, 16–61 met study inclusion criteria. Seven patients lost at least three Snellen lines of vision while the silicone oil was in place. Four patients had late modest improvements in acuity when compared to their final recorded Snellen vision before silicone oil removal, however no patients exhibited visual improvement when comparing their final recorded visual acuities after oil removal with best recorded acuities under oil tamponade. Loss of the foveal depression was a consistent feature on optical coherence tomography.Conclusions: Vision loss is a possible complication of silicone oil use and removal. Late visual improvement may occur in some patients. Further research is warranted to elucidate the mechanism(s of vision loss associated with the use or removal of silicone oil.Keywords: retinal tamponade, visual acuity, snellen vision, silicone oil

Bilateral idiopathic optic perineuritis with severe vision loss: A case report

Directory of Open Access Journals (Sweden)

Wee-Min Teh

2015-07-01

Full Text Available Optic perineuritis is an orbital inflammatory disorder that is either idiopathic or secondary to other conditions such as infection or systemic inflammatory disorders. This condition is very similar to demyelinating optic neuritis, but certain features of the history and magnetic resonance imaging findings are characteristic for and aid in the diagnosis of optic perineuritis. Vision loss varies greatly, from minimal clouding of vision up to only light perception. We report a case of a 44-year-old female with idiopathic bilateral optic perineuritis with vision loss of up to no light perception in both eyes. Radio imaging studies were typical of optic perineuritis and she was started on systemic corticosteroids. She responded very well to steroid therapy and achieved nearly complete visual recovery. There had been no relapse despite cessation of therapy.

New experimental diffractive-optical data on E.Land's Retinex mechanism in human color vision: Part II

Science.gov (United States)

Lauinger, N.

2007-09-01

A better understanding of the color constancy mechanism in human color vision [7] can be reached through analyses of photometric data of all illuminants and patches (Mondrians or other visible objects) involved in visual experiments. In Part I [3] and in [4, 5 and 6] the integration in the human eye of the geometrical-optical imaging hardware and the diffractive-optical hardware has been described and illustrated (Fig.1). This combined hardware represents the main topic of the NAMIROS research project (nano- and micro- 3D gratings for optical sensors) [8] promoted and coordinated by Corrsys 3D Sensors AG. The hardware relevant to (photopic) human color vision can be described as a diffractive or interference-optical correlator transforming incident light into diffractive-optical RGB data and relating local RGB onto global RGB data in the near-field behind the 'inverted' human retina. The relative differences at local/global RGB interference-optical contrasts are available to photoreceptors (cones and rods) only after this optical pre-processing.

Basic design principles of colorimetric vision systems

Science.gov (United States)

Mumzhiu, Alex M.

1998-10-01

Color measurement is an important part of overall production quality control in textile, coating, plastics, food, paper and other industries. The color measurement instruments such as colorimeters and spectrophotometers, used for production quality control have many limitations. In many applications they cannot be used for a variety of reasons and have to be replaced with human operators. Machine vision has great potential for color measurement. The components for color machine vision systems, such as broadcast quality 3-CCD cameras, fast and inexpensive PCI frame grabbers, and sophisticated image processing software packages are available. However the machine vision industry has only started to approach the color domain. The few color machine vision systems on the market, produced by the largest machine vision manufacturers have very limited capabilities. A lack of understanding that a vision based color measurement system could fail if it ignores the basic principles of colorimetry is the main reason for the slow progress of color vision systems. the purpose of this paper is to clarify how color measurement principles have to be applied to vision systems and how the electro-optical design features of colorimeters have to be modified in order to implement them for vision systems. The subject of this presentation far exceeds the limitations of a journal paper so only the most important aspects will be discussed. An overview of the major areas of applications for colorimetric vision system will be discussed. Finally, the reasons why some customers are happy with their vision systems and some are not will be analyzed.

Simulation of the color vision: decoding quantum-electric transduction

Directory of Open Access Journals (Sweden)

Élgion Lúcio da Silva Loreto

2008-08-01

Full Text Available We propose an experimental simulation, using accessible and low cost materials, on the biophysical mechanism of the color vision in accordance with the Young-Helmholtz s Trichromatic Theory, approaching mainly the coding and decoding process of electric signs that arrive to the cerebral cortex. The stimulus that unchains this process is given through transformation of the quantized energy of a light photon that takes place in the photocells of the retina of the human eye. The construction of a simple system of collection and analysis of data, using a multimeter, filters, LDR and LEDs allows us to establish connections between the visual system and the simulation model.

A Call for Considering Color Vision Deficiency When Creating Graphics for Psychology Reports.

Science.gov (United States)

Frane, Andrew

2015-01-01

Although color vision deficiency (CVD) is fairly common, it is often not adequately considered when data is presented in color graphics. This study found that CVD tends to be mentioned neither in the author guidelines of psychology journals nor in the standard publication manuals of the field (e.g., the publication manuals of the American Psychological Association and the American Medical Association). To illustrate the relevance of this problem, a panel of scholars with CVD was used to evaluate the color figures in three respected psychological science journals. Results suggested that a substantial proportion of those figures were needlessly confusing for viewers with CVD and could have been easily improved through simple adjustments. Based on prior literature and on feedback from the panelists, recommendations are made for improving the accessibility of graphics in psychology reports.

[Retinitis pigmentosa and color vision deficiency in Kamigoto island, Nagasaki Prefecture].

Science.gov (United States)

Toda, S

1997-08-01

I studied two genetic diseases, retinitis pigmentosa (RP) and color vision anomaly, in Kamigoto, one of the off-shore islands in Nagasaki Prefecture. The Prevalance of RP patients in this island was estimated to be one in 473 persons. Among the RP patients observed, familial cases whose disorders are transmitted through successive generations comprised 25.7%. Although it seems that the inheritance mode of RP in these familial cases is autosomal dominant, an autosomal recessive fashion showing quasi-dominance cannot be ruled out, because inbreeding frequently occurs on this island. There were at least two types of RP, one with late onset (40 years of age or later) and the other with early onset, and patients with the latter RP tended to have a poor prognosis. Only a few RP patients had posterior subcapsular cataract, and none had pseudexfoliation in spite of advanced age. Color vision anomalies were found in 3.86% of high-school boys and in 0.41% of girls in this island, and they included protanopia (4.2%), protanomaly (10.4%), deuteranopia (37.5%), and deuteranomaly (47.9%). The prevalence in boys was comparable to that in the general Japanese population, but the prevalence in girls was higher in Kamigoto than in other districts. It is most likely that the unique findings regarding the two disorders reflect geographical and/or social features in Kamigoto island.

A new technique for robot vision in autonomous underwater vehicles using the color shift in underwater imaging

Science.gov (United States)

2017-06-01

FOR ROBOT VISION IN AUTONOMOUS UNDERWATER VEHICLES USING THE COLOR SHIFT IN UNDERWATER IMAGING by Jake A. Jones June 2017 Thesis Advisor...techniques to determine the distances from each pixel to the camera. 14. SUBJECT TERMS unmanned undersea vehicles (UUVs), autonomous ... AUTONOMOUS UNDERWATER VEHICLES USING THE COLOR SHIFT IN UNDERWATER IMAGING Jake A. Jones Lieutenant Commander, United States Navy B.S

The prevalence of vision loss due to ocular trauma in the Australian National Eye Health Survey.

Science.gov (United States)

Keel, Stuart; Xie, Jing; Foreman, Joshua; Taylor, Hugh R; Dirani, Mohamed

2017-11-01

To determine the prevalence of vision loss due to ocular trauma in Australia. The National Eye Health Survey (NEHS) is a population-based cross-sectional study that examined 3098 non-Indigenous Australians (aged 50-98 years) and 1738 Indigenous Australians (aged 40-92 years) living in 30 randomly selected sites, stratified by remoteness. An eye was considered to have vision loss due to trauma if the best-corrected visual acuity was worse than 6/12 and the main cause was attributed to ocular trauma. This determination was made by two independent ophthalmologists and any disagreements were adjudicated by a third senior ophthalmologist. The sampling weight adjusted prevalence of vision loss due to ocular trauma in non-Indigenous Australians aged 50 years and older and Indigenous Australians aged 40 years and over was 0.24% (95%CI: 0.10, 0.52) and 0.79% (95%CI: 0.56, 1.13), respectively. Trauma was attributed as an underlying cause of bilateral vision loss in one Indigenous participant, with all other cases being monocular. Males displayed a higher prevalence of vision loss from ocular trauma than females in both the non-Indigenous (0.47% vs. 1.25%, p=0.03) and Indigenous populations (0.12% vs. 0.38%, p=0.02). After multivariate adjustments, residing in Very Remote geographical areas was associated with higher odds of vision loss from ocular trauma. We estimate that 2.4 per 1000 non-Indigenous and 7.9 per 1000 Indigenous Australian adults have monocular vision loss due to a previous severe ocular trauma. Our findings indicate that males, Indigenous Australians and those residing in Very Remote communities may benefit from targeted health promotion to improve awareness of trauma prevention strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reduced Discrimination in the Tritanopic Confusion Line for Congenital Color Deficiency Adults

Directory of Open Access Journals (Sweden)

Marcelo Fernandes Costa

2016-03-01

Full Text Available In congenital color blindness the red-green discrimination is impaired resulting in an increased confusion between those colors with yellow. Our post-receptoral physiological mechanisms are organized in two pathways for color perception, a red-green (protanopic and deuteranopic and a blue-yellow (tritanopic. We argue that the discrimination losses in the yellow area in congenital color vision deficiency subjects could generate a subtle loss of discriminability in the tritanopic channel considering discrepancies with yellow perception. We measured color discrimination thresholds for blue and yellow of tritanopic channel in congenital color deficiency subjects. Chromaticity thresholds were measured around a white background (0.1977 u’, 0.4689 v’ in the CIE 1976 consisting of a blue-white and white-yellow thresholds in a tritanopic color confusion line of 21 congenital colorblindness subjects (mean age = 27.7; SD= 5.6 years; 14 deuteranomalous and 7 protanomalous and of 82 (mean age = 25.1; SD= 3.7 years normal color vision subjects. Significant increase in the whole tritanopic axis was found for both deuteranomalous and protanomalous subjects compared to controls for the blue-white (F2,100= 18.80; p< 0.0001 and white-yellow (F2,100= 22.10; p< 0.0001 thresholds. A Principal Component Analysis found a weighting toward to the yellow thresholds induced by deuteranomalous subjects. In conclusion, the discrimination in the tritanopic color confusion axis is significantly reduced in congenital color vision deficiency compared to normal subjects. Since yellow discrimination was impaired the balance of the blue-yellow channels is impaired justifying the increased thresholds found for blue-white discrimination. The weighting toward the yellow region of the color space with the deuteranomalous contributing to that perceptual distortion is discussed in terms of physiological mechanisms.

Psychophysical Evaluation of Achromatic and Chromatic Vision of Workers Chronically Exposed to Organic Solvents

International Nuclear Information System (INIS)

Lacerda, E.M.D.B.; Lima, M.G.; Silveira, L.C.D.S.; Rodrigues, A.R.; Teixeira, C.E.C.; De Lima, L.J.B.; Silveira, L.C.D.S.; Ventura, D.F.; Ventura, D.F.

2012-01-01

The purpose of this paper was to evaluate achromatic and chromatic vision of workers chronically exposed to organic solvents through psychophysical methods. Thirty-one gas station workers (31.5 ± 8.4 years old) were evaluated. Psychophysical tests were achromatic tests (Snellen chart, spatial and temporal contrast sensitivity, and visual perimetry) and chromatic tests (Ishihara's test, color discrimination ellipses, and Farnsworth-Munsell 100 hue test FM100). Spatial contrast sensitivities of exposed workers were lower than the control at spatial frequencies of 20 and 30 cpd whilst the temporal contrast sensitivity was preserved. Visual field losses were found in 10-30 degrees of eccentricity in the solvent exposed workers. The exposed workers group had higher error values of FM100 and wider color discrimination ellipses area compared to the controls. Workers occupationally exposed to organic solvents had abnormal visual functions, mainly color vision losses and visual field constriction

Epistatic adaptive evolution of human color vision.

Directory of Open Access Journals (Sweden)

Shozo Yokoyama

2014-12-01

Full Text Available Establishing genotype-phenotype relationship is the key to understand the molecular mechanism of phenotypic adaptation. This initial step may be untangled by analyzing appropriate ancestral molecules, but it is a daunting task to recapitulate the evolution of non-additive (epistatic interactions of amino acids and function of a protein separately. To adapt to the ultraviolet (UV-free retinal environment, the short wavelength-sensitive (SWS1 visual pigment in human (human S1 switched from detecting UV to absorbing blue light during the last 90 million years. Mutagenesis experiments of the UV-sensitive pigment in the Boreoeutherian ancestor show that the blue-sensitivity was achieved by seven mutations. The experimental and quantum chemical analyses show that 4,008 of all 5,040 possible evolutionary trajectories are terminated prematurely by containing a dehydrated nonfunctional pigment. Phylogenetic analysis further suggests that human ancestors achieved the blue-sensitivity gradually and almost exclusively by epistasis. When the final stage of spectral tuning of human S1 was underway 45-30 million years ago, the middle and long wavelength-sensitive (MWS/LWS pigments appeared and so-called trichromatic color vision was established by interprotein epistasis. The adaptive evolution of human S1 differs dramatically from orthologous pigments with a major mutational effect used in achieving blue-sensitivity in a fish and several mammalian species and in regaining UV vision in birds. These observations imply that the mechanisms of epistatic interactions must be understood by studying various orthologues in different species that have adapted to various ecological and physiological environments.

Relative advantages of dichromatic and trichromatic color vision in camouflage breaking.

Science.gov (United States)

Troscianko, Jolyon; Wilson-Aggarwal, Jared; Griffiths, David; Spottiswoode, Claire N; Stevens, Martin

2017-01-01

There is huge diversity in visual systems and color discrimination abilities, thought to stem from an animal's ecology and life history. Many primate species maintain a polymorphism in color vision, whereby most individuals are dichromats but some females are trichromats, implying that selection sometimes favors dichromatic vision. Detecting camouflaged prey is thought to be a task where dichromatic individuals could have an advantage. However, previous work either has not been able to disentangle camouflage detection from other ecological or social explanations, or did not use biologically relevant cryptic stimuli to test this hypothesis under controlled conditions. Here, we used online "citizen science" games to test how quickly humans could detect cryptic birds (incubating nightjars) and eggs (of nightjars, plovers and coursers) under trichromatic and simulated dichromatic viewing conditions. Trichromats had an overall advantage, although there were significant differences in performance between viewing conditions. When searching for consistently shaped and patterned adult nightjars, simulated dichromats were more heavily influenced by the degree of pattern difference than were trichromats, and were poorer at detecting prey with inferior pattern and luminance camouflage. When searching for clutches of eggs-which were more variable in appearance and shape than the adult nightjars-the simulated dichromats learnt to detect the clutches faster, but were less sensitive to subtle luminance differences. These results suggest there are substantial differences in the cues available under viewing conditions that simulate different receptor types, and that these interact with the scene in complex ways to affect camouflage breaking.

Theoretical research on color indirect effects

Science.gov (United States)

Liu, T. C.; Liao, Changjun; Liu, Songhao

1995-05-01

Color indirect effects (CIE) means the physiological and psychological effects of color resulting from color vision. In this paper, we study CIE from the viewpoints of the integrated western and Chinese traditional medicine and the time quantum theory established by C. Y. Liu et al., respectively, and then put forward the color-automatic-nervous-subsystem model that could color excites parasympathetic subsystem and hot color excites sympathetic subsystem. Our theory is in agreement with modern color vision theory, and moreover, it leads to the resolution of the conflict between the color code theory and the time code theory oncolor vision. For the latitude phenomena on athlete stars number and the average lifespan, we also discuss the possibility of UV vision. The applications of our theory lead to our succeeding in explaining a number of physiological and psychological effects of color, in explaining the effects of age on color vision, and in explaining the Chinese chromophototherapy. We also discuss its application to neuroimmunology. This research provides the foundation of the clinical applications of chromophototherapy.

Neurogenic vision loss: Causes and outcome. An experience from a tertiary center in Northern India

Directory of Open Access Journals (Sweden)

Rajesh Verma

2014-01-01

Full Text Available Introduction: Vision loss can be a consequence of numerous disorders of eye and neural pathway conveying visual input to brain. A variety of conditions can affect visual pathway producing neurogenic vision loss. The presentation and course of vision loss depends on the site of involvement and underlying etiology. We conducted this unprecedented study to evaluate the characteristics and outcome of various diseases of the visual pathway. Materials and Methods: In this prospective cohort study, we evaluated 64 patients with neurogenic visual impairment. Ophthalmological causes were excluded in all of them. Their presentation, ophthalmological characteristics and investigation findings were recorded. These patients were followed up till 6 months. Results: Out of 69 patients evaluated, 5 were excluded as they had ophthalmological abnormalities. The remaining 64 cases (113 eyes were enrolled. 54 cases were due to diseases of anterior visual pathway and rest 10 had cortical vision loss. The etiologic distribution is as follows: Isolated optic neuritis- 12 (19%, multiple sclerosis- 4 (6.3%, neuromyelitis optica- 5 (7.9%, tubercular meningitis- 15 (23.8%, non-arteritic ischemic optic neuropathy, ischemic optic neuropathy complicating cavernous sinus thrombosis, cryptococcal meningitis, malignant infiltration of optic nerve, Crouzon′s syndrome, calvarial thickening and traumatic occipital gliosis- 1 (1.6% case each, idiopathic intracranial hypertension, pituitary adenoma, acute disseminated encephalomyelitis, posterior reversible leukoencephalopathy- 3 (4.8% cases each, cortical venous thrombosis 5 (7.9%, subacute scleroing panencephalitis- 4 (6.3% cases. Conclusions: The diseases of anterior visual pathway were much more common than cortical vision loss. A majority of our patients had severe impairment of vision at presentation.

Acute Zonal Cone Photoreceptor Outer Segment Loss.

Science.gov (United States)

Aleman, Tomas S; Sandhu, Harpal S; Serrano, Leona W; Traband, Anastasia; Lau, Marisa K; Adamus, Grazyna; Avery, Robert A

2017-05-01

The diagnostic path presented narrows down the cause of acute vision loss to the cone photoreceptor outer segment and will refocus the search for the cause of similar currently idiopathic conditions. To describe the structural and functional associations found in a patient with acute zonal occult photoreceptor loss. A case report of an adolescent boy with acute visual field loss despite a normal fundus examination performed at a university teaching hospital. Results of a complete ophthalmic examination, full-field flash electroretinography (ERG) and multifocal ERG, light-adapted achromatic and 2-color dark-adapted perimetry, and microperimetry. Imaging was performed with spectral-domain optical coherence tomography (SD-OCT), near-infrared (NIR) and short-wavelength (SW) fundus autofluorescence (FAF), and NIR reflectance (REF). The patient was evaluated within a week of the onset of a scotoma in the nasal field of his left eye. Visual acuity was 20/20 OU, and color vision was normal in both eyes. Results of the fundus examination and of SW-FAF and NIR-FAF imaging were normal in both eyes, whereas NIR-REF imaging showed a region of hyporeflectance temporal to the fovea that corresponded with a dense relative scotoma noted on light-adapted static perimetry in the left eye. Loss in the photoreceptor outer segment detected by SD-OCT co-localized with an area of dense cone dysfunction detected on light-adapted perimetry and multifocal ERG but with near-normal rod-mediated vision according to results of 2-color dark-adapted perimetry. Full-field flash ERG findings were normal in both eyes. The outer nuclear layer and inner retinal thicknesses were normal. Localized, isolated cone dysfunction may represent the earliest photoreceptor abnormality or a distinct entity within the acute zonal occult outer retinopathy complex. Acute zonal occult outer retinopathy should be considered in patients with acute vision loss and abnormalities on NIR-REF imaging, especially if

Cross-media color reproduction using the frequency-based spatial gamut mapping algorithm based on human color vision

Science.gov (United States)

Wu, Guangyuan; Niu, Shijun; Li, Xiaozhou; Hu, Guichun

2018-04-01

Due to the increasing globalization of printing industry, remoting proofing will become the inevitable development trend. Cross-media color reproduction will occur in different color gamuts using remote proofing technologies, which usually leads to the problem of incompatible color gamut. In this paper, to achieve equivalent color reproduction between a monitor and a printer, a frequency-based spatial gamut mapping algorithm is proposed for decreasing the loss of visual color information. The design of algorithm is based on the contrast sensitivity functions (CSF), which exploited CSF spatial filter to preserve luminance of the high spatial frequencies and chrominance of the low frequencies. First we show a general framework for how to apply CSF spatial filter in retention of relevant visual information. Then we compare the proposed framework with HPMINDE, CUSP, Bala's algorithm. The psychophysical experimental results indicated the good performance of the proposed algorithm.

Cone photoreceptor structure in patients with x-linked cone dysfunction and red-green color vision deficiency

DEFF Research Database (Denmark)

Patterson, Emily J.; Wilk, Melissa; Langlo, Christopher S.

2016-01-01

encoded by exon 4, and two with a novel insertion in exon 2. Foveal cone structure and retinal thickness was disrupted to a variable degree, even among related individuals with the same L/M array. CONCLUSIONS. Our findings provide a direct link between disruption of the cone mosaic and L/ M opsin variants......PURPOSE. Mutations in the coding sequence of the L and M opsin genes are often associated with X-linked cone dysfunction (such as Bornholm Eye Disease, BED), though the exact color vision phenotype associated with these disorders is variable. We examined individuals with L/ M opsin gene mutations...... to clarify the link between color vision deficiency and cone dysfunction.  METHODS. We recruited 17 males for imaging. The thickness and integrity of the photoreceptor layers were evaluated using spectral-domain optical coherence tomography. Cone density was measured using high-resolution images of the cone...

Color-based scale-invariant feature detection applied in robot vision

Science.gov (United States)

Gao, Jian; Huang, Xinhan; Peng, Gang; Wang, Min; Li, Xinde

2007-11-01

The scale-invariant feature detecting methods always require a lot of computation yet sometimes still fail to meet the real-time demands in robot vision fields. To solve the problem, a quick method for detecting interest points is presented. To decrease the computation time, the detector selects as interest points those whose scale normalized Laplacian values are the local extrema in the nonholonomic pyramid scale space. The descriptor is built with several subregions, whose width is proportional to the scale factor, and the coordinates of the descriptor are rotated in relation to the interest point orientation just like the SIFT descriptor. The eigenvector is computed in the original color image and the mean values of the normalized color g and b in each subregion are chosen to be the factors of the eigenvector. Compared with the SIFT descriptor, this descriptor's dimension has been reduced evidently, which can simplify the point matching process. The performance of the method is analyzed in theory in this paper and the experimental results have certified its validity too.

Mental stress as consequence and cause of vision loss: the dawn of psychosomatic ophthalmology for preventive and personalized medicine.

Science.gov (United States)

Sabel, Bernhard A; Wang, Jiaqi; Cárdenas-Morales, Lizbeth; Faiq, Muneeb; Heim, Christine

2018-06-01

The loss of vision after damage to the retina, optic nerve, or brain has often grave consequences in everyday life such as problems with recognizing faces, reading, or mobility. Because vision loss is considered to be irreversible and often progressive, patients experience continuous mental stress due to worries, anxiety, or fear with secondary consequences such as depression and social isolation. While prolonged mental stress is clearly a consequence of vision loss, it may also aggravate the situation. In fact, continuous stress and elevated cortisol levels negatively impact the eye and brain due to autonomous nervous system (sympathetic) imbalance and vascular dysregulation; hence stress may also be one of the major causes of visual system diseases such as glaucoma and optic neuropathy. Although stress is a known risk factor, its causal role in the development or progression of certain visual system disorders is not widely appreciated. This review of the literature discusses the relationship of stress and ophthalmological diseases. We conclude that stress is both consequence and cause of vision loss. This creates a vicious cycle of a downward spiral, in which initial vision loss creates stress which further accelerates vision loss, creating even more stress and so forth. This new psychosomatic perspective has several implications for clinical practice. Firstly, stress reduction and relaxation techniques (e.g., meditation, autogenic training, stress management training, and psychotherapy to learn to cope) should be recommended not only as complementary to traditional treatments of vision loss but possibly as preventive means to reduce progression of vision loss. Secondly, doctors should try their best to inculcate positivity and optimism in their patients while giving them the information the patients are entitled to, especially regarding the important value of stress reduction. In this way, the vicious cycle could be interrupted. More clinical studies are now

Usability of light-emitting diodes in precision approach path indicator systems by individuals with marginal color vision.

Science.gov (United States)

2014-05-01

To save energy, the FAA is planning to convert from incandescent lights to light-emitting diodes (LEDs) in : precision approach path indicator (PAPI) systems. Preliminary work on the usability of LEDs by color vision-waivered pilots (Bullough, Skinne...

Wavelength Discrimination in Drosophila Suggests a Role of Rhodopsin 1 in Color Vision

OpenAIRE

Garbers, Christian; Wachtler, Thomas

2016-01-01

Among the five photoreceptor opsins in the eye of Drosophila, Rhodopsin 1 (Rh1) is expressed in the six outer photoreceptors. In a previous study that combined behavioral genetics with computational modeling, we demonstrated that flies can use the signals from Rh1 for color vision. Here, we provide an in-depth computational analysis of wildtype Drosophila wavelength discrimination specifically considering the consequences of different choices of computations in the preprocessing of the behavi...

Serum low-density lipoprotein cholesterol level is strong risk factor for acquired color vision impairment in young to middle-aged Japanese men: the Okubo Color Study Report 2.

Science.gov (United States)

Shoji, Takuhei; Sakurai, Yutaka; Sato, Hiroki; Chihara, Etsuo; Ishida, Masahiro; Omae, Kazuyuki

2010-06-01

To investigate associations between blood low-density lipoprotein cholesterol (LDL-C) levels and the prevalence of acquired color vision impairment (ACVI) in middle-aged Japanese men. Participants in this cross-sectional study underwent color vision testing, ophthalmic examination, a standardized interview and examination of venous blood samples. Ishihara plates, a Lanthony 15-hue desaturated panel, and Standard pseudoisochromatic Plates part 2 were used to examine color vision ability. The Farnsworth-Munsell 100-hue test was performed to define ACVI. Smoking status and alcohol intake were recorded during the interview. We performed logistic regression analysis adjusted for age, LDL-C level, systemic hypertension, diabetes, cataract, glaucoma, overweight, smoking status, and alcohol intake. Adjusted odds ratios for four LDL-C levels were calculated. A total of 1042 men were enrolled, 872 participants were eligible for the study, and 31 subjects were diagnosed with ACVI. As compared to the lowest LDL-C category level (or=160 mg/dl). The multiple-adjusted ORs were 2.91 (95% CI, 0.87-9.70) for the 2nd highest category and 3.81 (95% CI, 1.03-14.05) for the highest level. Tests for trend were significant (Pmen with elevated LDL-C levels. These changes might be related to deteriorated neurologic function associated with lipid metabolite abnormalities. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.

Loss of binocular vision as direct cause for misrouting of temporal retinal fibers in albinism.

Science.gov (United States)

Banihani, Saleh M

2015-10-01

In humans, the nasal retina projects to the contralateral hemisphere, whereas the temporal retina projects ipsilaterally. The nasotemporal line that divides the retina into crossed and uncrossed parts coincides with the vertical meridian through the fovea. This normal projection of the retina is severely altered in albinism, in which the nasotemporal line shifted into the temporal retina with temporal retinal fibers cross the midline at the optic chiasm. This study proposes the loss of binocular vision as direct cause for misrouting of temporal retinal fibers and shifting of the nasotemporal line temporally in albinism. It is supported by many observations that clearly indicate that loss of binocular vision causes uncrossed retinal fibers to cross the midline. This hypothesis may alert scientists and clinicians to find ways to prevent or minimize the loss of binocular vision that may occur in some diseases such as albinism and early squint. Hopefully, this will minimize the misrouting of temporal fibers and improve vision in such diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.

Predictors of vision impairment in Multiple Sclerosis.

Science.gov (United States)

Sanchez-Dalmau, Bernardo; Martinez-Lapiscina, Elena H; Pulido-Valdeolivas, Irene; Zubizarreta, Irati; Llufriu, Sara; Blanco, Yolanda; Sola-Valls, Nuria; Sepulveda, Maria; Guerrero, Ana; Alba, Salut; Andorra, Magi; Camos, Anna; Sanchez-Vela, Laura; Alfonso, Veronica; Saiz, Albert; Villoslada, Pablo

2018-01-01

Visual impairment significantly alters the quality of life of people with Multiple Sclerosis (MS). The objective of this study was to identify predictors (independent variables) of visual outcomes, and to define their relationship with neurological disability and retinal atrophy when assessed by optical coherence tomography (OCT). We performed a cross-sectional analysis of 119 consecutive patients with MS, assessing vision using high contrast visual acuity (LogMar), 2.5% and 1.25% low contrast visual acuity (Sloan charts), and color vision (Hardy-Rand-Rittler plates). Quality of vision is a patient reported outcome based on an individual's unique perception of his or her vision and was assessed with the Visual Functioning Questionnaire-25 (VFQ-25) with the 10 neuro-ophthalmologic items. MS disability was assessed using the expanded disability status scale (EDSS), the MS functional composite (MSFC) and the brief repetitive battery-neuropsychology (BRB-N). Retinal atrophy was assessed using spectral domain OCT, measuring the thickness of the peripapillar retinal nerve fiber layer (pRNFL) and the volume of the ganglion cell plus inner plexiform layer (GCIPL). The vision of patients with MS was impaired, particularly in eyes with prior optic neuritis. Retinal atrophy (pRNFL and GCIPL) was closely associated with impaired low contrast vision and color vision, whereas the volume of the GCIPL showed a trend (p = 0.092) to be associated with quality of vision. Multiple regression analysis revealed that EDSS was an explanatory variable for high contrast vision after stepwise analysis, GCIPL volume for low contrast vision, and GCIPL volume and EDSS for color vision. The explanatory variables for quality of vision were high contrast vision and color vision. In summary, quality of vision in MS depends on the impairment of high contrast visual acuity and color vision due to the disease.

Space grating optical structure of the retina and RGB-color vision.

Science.gov (United States)

Lauinger, Norbert

2017-02-01

Diffraction of light at the spatial cellular phase grating outer nuclear layer of the retina could produce Fresnel near-field interferences in three RGB diffraction orders accessible to photoreceptors (cones/rods). At perpendicular light incidence the wavelengths of the RGB diffraction orders in photopic vision-a fundamental R-wave with two G+B-harmonics-correspond to the peak wavelengths of the spectral brightness sensitivity curves of the cones at 559 nmR, 537 nmG, and 447 nmB. In scotopic vision the R+G diffraction orders optically fuse at 512 nm, the peak value of the rod's spectral brightness sensitivity curve. The diffractive-optical transmission system with sender (resonator), space waves, and receiver antennae converts the spectral light components involved in imaging into RGB space. The colors seen at objects are diffractive-optical products in the eye, as the German philosopher A. Schopenhauer predicted. They are second related to the overall illumination in object space. The RGB transmission system is the missing link optically managing the spectral tuning of the RGB photopigments.

Portable real-time color night vision

NARCIS (Netherlands)

Toet, A.; Hogervorst, M.A.

2008-01-01

We developed a simple and fast lookup-table based method to derive and apply natural daylight colors to multi-band night-time images. The method deploys an optimal color transformation derived from a set of samples taken from a daytime color reference image. The colors in the resulting colorized

Contact Lenses for Color Blindness.

Science.gov (United States)

Badawy, Abdel-Rahman; Hassan, Muhammad Umair; Elsherif, Mohamed; Ahmed, Zubair; Yetisen, Ali K; Butt, Haider

2018-06-01

Color vision deficiency (color blindness) is an inherited genetic ocular disorder. While no cure for this disorder currently exists, several methods can be used to increase the color perception of those affected. One such method is the use of color filtering glasses which are based on Bragg filters. While these glasses are effective, they are high cost, bulky, and incompatible with other vision correction eyeglasses. In this work, a rhodamine derivative is incorporated in commercial contact lenses to filter out the specific wavelength bands (≈545-575 nm) to correct color vision blindness. The biocompatibility assessment of the dyed contact lenses in human corneal fibroblasts and human corneal epithelial cells shows no toxicity and cell viability remains at 99% after 72 h. This study demonstrates the potential of the dyed contact lenses in wavelength filtering and color vision deficiency management. © 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Color machine vision system for process control in the ceramics industry

Science.gov (United States)

Penaranda Marques, Jose A.; Briones, Leoncio; Florez, Julian

1997-08-01

This paper is focused on the design of a machine vision system to solve a problem found in the manufacturing process of high quality polished porcelain tiles. This consists of sorting the tiles according to the criteria 'same appearance to the human eye' or in other words, by color and visual texture. In 1994 this problem was tackled and led to a prototype which became fully operational at production scale in a manufacturing plant, named Porcelanatto, S.A. The system has evolved and has been adapted to meet the particular needs of this manufacturing company. Among the main issues that have been improved, it is worth pointing out: (1) improvement to discern subtle variations in color or texture, which are the main features of the visual appearance; (2) inspection time reduction, as a result of algorithm optimization and the increasing computing power. Thus, 100 percent of the production can be inspected, reaching a maximum of 120 tiles/sec.; (3) adaptation to the different types and models of tiles manufactured. The tiles vary not only in their visible patterns but also in dimensions, formats, thickness and allowances. In this sense, one major problem has been reaching an optimal compromise: The system must be sensitive enough to discern subtle variations in color, but at the same time insensitive thickness variations in the tiles. The following parts have been used to build the system: RGB color line scan camera, 12 bits per channel, PCI frame grabber, PC, fiber optic based illumination and the algorithm which will be explained in section 4.

Eleven Colors That Are Almost Never Confused

Science.gov (United States)

Boynton, Robert M.

1989-08-01

1.1. Three functions of color vision. Setting aside the complex psychological effects of color, related to esthetics, fashion, and mood, three relatively basic functions of color vision, which can be examined scientifically, are discernable. (1) With the eye in a given state of adaptation, color vision allows the perception of signals that otherwise would be below threshold, and therefore lost to perception. Evidence for this comes from a variety of two-color threshold experiments. (2) Visible contours can be maintained by color differences alone, regardless of the relative radiances of the two parts of the field whose junction defines the border. For achromatic vision, contour disappears at the isoluminant point. (3) Color specifies what seems to be an absolute property of a surface, one that enhances its recognizability and allows a clearer separation and classification of non-contiguous elements in the visual field.

Adjustment to acquired vision loss in adults presenting for visual disability certification.

Science.gov (United States)

Nakade, Aditya; Rohatgi, Jolly; Bhatia, Manjeet S; Dhaliwal, Upreet

2017-03-01

Rehabilitation of the visually disabled depends on how they adjust to loss; understanding contributing factors may help in effective rehabilitation. The aim of this study is to assess adjustment to acquired vision loss in adults. This observational study, conducted in the Department of Ophthalmology at a tertiary-level teaching hospital, included thirty persons (25-65 years) with visual disability, might contribute to reducing stress and depression.

Comparison of the color of natural teeth measured by a colorimeter and Shade Vision System.

Science.gov (United States)

Cho, Byeong-Hoon; Lim, Yong-Kyu; Lee, Yong-Keun

2007-10-01

The objectives were to measure the difference in the color and color parameters of natural teeth measured by a tristimulus colorimeter (CM, used as a reference) and Shade Vision System (SV), and to determine the influence of color parameters on the color difference between the values measured by two instruments. Color of 12 maxillary and mandibular anterior teeth was measured by CM and SV for 47 volunteers (number of teeth=564). Color parameters such as CIE L*, a* and b* values, chroma and hue angle measured by two instruments were compared. Chroma was calculated as C*ab=(a*2 = b*2)1/2, and hue angle was calculated as h degrees =arctan(b*/a*). The influence of color parameters measured by CM on the color difference (DeltaE*(ab)) between the values measured by two instruments was analyzed with multiple regression analysis (alpha=0.01). Mean DeltaE*(ab) value between the values measured by two instruments was 21.7 (+/-3.7), and the mean difference in lightness (CIE L*) and chroma was 16.2 (+/-3.9) and 13.2 (+/-3.0), respectively. Difference in hue angle was high as 132.7 (+/-53.3) degrees . Except for the hue angle, all the color parameters showed significant correlations and the coefficient of determination (r(2)) was in the range of 0.089-0.478. Based on multiple regression analysis, the standardized partial correlation coefficient (beta) of the included predictors for the color difference was -0.710 for CIE L* and -0.300 for C*(ab) (p<0.01). All the color parameters showed significant but weak correlations except for hue angle. When lightness and chroma of teeth were high, color difference between the values measured by two instruments was small. Clinical accuracy of two instruments should be investigated further.

Psychologic adjustment to irreversible vision loss in adults: a systematic review.

Science.gov (United States)

Senra, Hugo; Barbosa, Fernando; Ferreira, Patrícia; Vieira, Cristina R; Perrin, Paul B; Rogers, Heather; Rivera, Diego; Leal, Isabel

2015-04-01

To summarize relevant evidence investigating the psychologic adjustment to irreversible vision loss (IVL) in adults. Irreversible vision loss entails a challenging medical condition in which rehabilitation outcomes are strongly dependent on the patient's psychologic adjustment to illness and impairment. So far, no study has systematically reviewed the psychologic adjustment to IVL in adults. We reviewed all articles examining the psychologic adjustment to IVL in adults. We included articles published in English in peer-reviewed journals. We performed a keyword literature search using 4 databases (PubMed, EBSCO, Cochrane Library, and Science Direct) for all years through July 2014. We assessed risk of bias of selected studies using the RTI Item Bank for Assessing Risk of Bias and Confounding for Observational Studies of Interventions or Exposures and the Cochrane risk of bias tool for randomized controlled trials. Of a total of 3948 citations retrieved, we selected 52 eligible studies published between 1946 and 2014. The majority of studies were observational and cross-sectional in nature. Our review suggests that high levels of depression occur during the adjustment to IVL. Better adjustment to IVL was associated with greater acceptance of vision loss and use of instrumental coping, good social support, positivity, and use of assistive aids. The overall findings indicate that IVL often has negative effects on patients' quality of life and mental health and that such effects tend to remain over time. Specific factors and variables associated with the adjustment to IVL need to be clarified through further in-depth and longitudinal research. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Muller cell-specific autoantibodies in a patient with progressive loss of vision

NARCIS (Netherlands)

Peek, R.; Verbraak, F.; Coevoet, H. M.; Kijlstra, A.

1998-01-01

PURPOSE. To study the specificity of circulating retinal autoantibodies in a patient with progressive loss of vision resembling cancer-associated retinopathy in the absence of systemic malignancy. METHODS. Patient's serum was tested for the presence of antiretinal antibodies by Western blot

Developing a machine vision system for simultaneous prediction of freshness indicators based on tilapia (Oreochromis niloticus) pupil and gill color during storage at 4°C.

Science.gov (United States)

Shi, Ce; Qian, Jianping; Han, Shuai; Fan, Beilei; Yang, Xinting; Wu, Xiaoming

2018-03-15

The study assessed the feasibility of developing a machine vision system based on pupil and gill color changes in tilapia for simultaneous prediction of total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA) and total viable counts (TVC) during storage at 4°C. The pupils and gills were chosen and color space conversion among RGB, HSI and L ∗ a ∗ b ∗ color spaces was performed automatically by an image processing algorithm. Multiple regression models were established by correlating pupil and gill color parameters with TVB-N, TVC and TBA (R 2 =0.989-0.999). However, assessment of freshness based on gill color is destructive and time-consuming because gill cover must be removed before images are captured. Finally, visualization maps of spoilage based on pupil color were achieved using image algorithms. The results show that assessment of tilapia pupil color parameters using machine vision can be used as a low-cost, on-line method for predicting freshness during 4°C storage. Copyright © 2017 Elsevier Ltd. All rights reserved.

Computer vision based room interior design

Science.gov (United States)

Ahmad, Nasir; Hussain, Saddam; Ahmad, Kashif; Conci, Nicola

2015-12-01

This paper introduces a new application of computer vision. To the best of the author's knowledge, it is the first attempt to incorporate computer vision techniques into room interior designing. The computer vision based interior designing is achieved in two steps: object identification and color assignment. The image segmentation approach is used for the identification of the objects in the room and different color schemes are used for color assignment to these objects. The proposed approach is applied to simple as well as complex images from online sources. The proposed approach not only accelerated the process of interior designing but also made it very efficient by giving multiple alternatives.

Preferred memory color difference between the deuteranomalous and normal color vision

Science.gov (United States)

Baek, YeSeul; Kwak, Youngshin; Woo, Sungjoo; Park, Chongwook

2015-01-01

The goal of this study is to evaluate the difference of the preferred hues of familiar objects between the color deficient observer and the normal observer. Thirteen test color images were chosen covering fruit colors, natural scene and human faces. It contained red, yellow, green, blue, purple and skin color. Two color deficient observer (deuteranomal) and two normal observers were participated in this experiment. They controlled the YCC hue of the objects in the images to obtain the most preferred and the most natural image. The selected images were analyzed using CIELAB values of each pixel. Data analysis results showed that in the case of naturalness, both groups selected the similar hues for the most of image, while, in the case of preference, the color deficient observer preferred more reddish or more greenish images. Since the deuteranomalous observer has relatively week perception for red and green region, they may prefer more reddish or greenish color. The color difference between natural hue and preferred hue of deuteranomal observer is bigger than those of normal observer.

What Is Low Vision?

Science.gov (United States)

... Your Rights Training Resources Workplace Technology CareerConnect Stories Working as a Senior with Vision Loss For Seniors Age-Related Vision ... Changes Health and Aging Retirement Living Continuing to Work as a Senior with Vision Loss Get Connected About VisionAware Join ...

Evolution of cichlid vision via trans-regulatory divergence

Directory of Open Access Journals (Sweden)

O’Quin Kelly E

2012-12-01

Full Text Available Abstract Background Phenotypic evolution may occur through mutations that affect either the structure or expression of protein-coding genes. Although the evolution of color vision has historically been attributed to structural mutations within the opsin genes, recent research has shown that opsin regulatory mutations can also tune photoreceptor sensitivity and color vision. Visual sensitivity in African cichlid fishes varies as a result of the differential expression of seven opsin genes. We crossed cichlid species that express different opsin gene sets and scanned their genome for expression Quantitative Trait Loci (eQTL responsible for these differences. Our results shed light on the role that different structural, cis-, and trans-regulatory mutations play in the evolution of color vision. Results We identified 11 eQTL that contribute to the divergent expression of five opsin genes. On three linkage groups, several eQTL formed regulatory “hotspots” associated with the expression of multiple opsins. Importantly, however, the majority of the eQTL we identified (8/11 or 73% occur on linkage groups located trans to the opsin genes, suggesting that cichlid color vision has evolved primarily via trans-regulatory divergence. By modeling the impact of just two of these trans-regulatory eQTL, we show that opsin regulatory mutations can alter cichlid photoreceptor sensitivity and color vision at least as much as opsin structural mutations can. Conclusions Combined with previous work, we demonstrate that the evolution of cichlid color vision results from the interplay of structural, cis-, and especially trans-regulatory loci. Although there are numerous examples of structural and cis-regulatory mutations that contribute to phenotypic evolution, our results suggest that trans-regulatory mutations could contribute to phenotypic divergence more commonly than previously expected, especially in systems like color vision, where compensatory changes in the

Acute loss of vision in a young woman: A case report on ...

African Journals Online (AJOL)

Background: Acute loss of vision needs urgent attention and treatment. We report on a young Ethiopian woman who experienced acute bilateral blindness. In the presence of normal ophthalmological findings psychogenic blindness has to be considered. Case Details: A 21 years old woman was admitted to the psychiatry ...

Colored Contact Lens Dangers

Medline Plus

Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... Costume Contact Lenses Can Ruin Vision Eye Makeup Safety In fact, it is illegal to sell colored ...

TrkB Activators for the Treatment of Traumatic Vision Loss

Science.gov (United States)

2016-10-01

appropriate dry eye treatment . Such optimized treatment is of major interest as possible scarring of the filtration site is a known major threat for...Society for Eye Resear... http://www.abstractserver.com/iser2016/absmgm/printpreview.php? 1 of 1 5/26/16, 11:25 AM ORAL PRESEN TATIONS Ocular...for the treatment of t rauma-induced vision loss. Activation of the Innate Immune System Following Blast Injury to the Eye ELDON GEISERT, Felix

The evolution of concepts of color vision.

Science.gov (United States)

Lee, Barry B

2008-07-01

The evolution of ideas about the way we see color was closely linked to physical theories of light. Proponents of both corpuscular and wave theories viewed light as a continuous spectrum. This was not easily reconciled with the fact that, for the human eye, all colors can be matched by mixture of three primaries. Physicists such as Mayer who described trichromatic color matching often assumed that there were just three types of rays in the spectrum. This argument was finally resolved by Thomas Young, who noted that trichromatic color matching was consistent with a continuous spectrum if there were just three receptors in the eye. This kind of conceptual mistake, in this case the confusion of the properties of the visual system with physical properties of light, has been common in the history of color science. As another example, the idea of trichromacy was disputed by those who viewed color sensations as opponent processes, red-green, blue-yellow and black-white. The discovery of color-opponent neurons in the visual pathway has partly resolved this dilemma. Much of the physiological substrate of the way we detect and distinguish colors is now established, but the link between the signals leaving the retina and the way we name and order colors is still poorly defined.

Lentes de contato filtrantes coloridas nas discromatopsias: relato de casos Absorptive and colored contact lenses in color-vision defects: case report

Directory of Open Access Journals (Sweden)

Luciene Chaves Fernandes

2003-06-01

test. Subject # 2 showed an subjective reduced glare, in external and internal environment. Visual acuity and color vision remained the same. The findings suggest the use of absorptive colored contact lenses to increase color judgement and reduce glare sensitivity in dichromatic subjects.

Color Constancy by Deep Learning

NARCIS (Netherlands)

Lou, Z.; Gevers, T.; Hu, N.; Lucassen, M.P.; Xie, X.; Jones, M.W.; Tam, G.K.L.

2015-01-01

Computational color constancy aims to estimate the color of the light source. The performance of many vision tasks, such as object detection and scene understanding, may benefit from color constancy by estimating the correct object colors. Since traditional color constancy methods are based on

Spatial imaging in color and HDR: prometheus unchained

Science.gov (United States)

McCann, John J.

2013-03-01

The Human Vision and Electronic Imaging Conferences (HVEI) at the IS and T/SPIE Electronic Imaging meetings have brought together research in the fundamentals of both vision and digital technology. This conference has incorporated many color disciplines that have contributed to the theory and practice of today's imaging: color constancy, models of vision, digital output, high-dynamic-range imaging, and the understanding of perceptual mechanisms. Before digital imaging, silver halide color was a pixel-based mechanism. Color films are closely tied to colorimetry, the science of matching pixels in a black surround. The quanta catch of the sensitized silver salts determines the amount of colored dyes in the final print. The rapid expansion of digital imaging over the past 25 years has eliminated the limitations of using small local regions in forming images. Spatial interactions can now generate images more like vision. Since the 1950's, neurophysiology has shown that post-receptor neural processing is based on spatial interactions. These results reinforced the findings of 19th century experimental psychology. This paper reviews the role of HVEI in color, emphasizing the interaction of research on vision and the new algorithms and processes made possible by electronic imaging.

Dirt detection on brown eggs by means of color computer vision.

Science.gov (United States)

Mertens, K; De Ketelaere, B; Kamers, B; Bamelis, F R; Kemps, B J; Verhoelst, E M; De Baerdemaeker, J G; Decuypere, E M

2005-10-01

In the last 20 yr, different methods for detecting defects in eggs were developed. Until now, no satisfying technique existed to sort and quantify dirt on eggshells. The work presented here focuses on the design of an off-line computer vision system to differentiate and quantify the presence of different dirt stains on brown eggs: dark (feces), white (uric acid), blood, and yolk stains. A system that provides uniform light exposure around the egg was designed. In this uniform light, pictures of dirty and clean eggs were taken, stored, and analyzed. The classification was based on a few standard logical operators, allowing for a quick implementation in an online set-up. In an experiment, 100 clean and 100 dirty eggs were used to validate the classification algorithm. The designed vision system showed an accuracy of 99% for the detection of dirt stains. Two percent of the clean eggs had a light-colored eggshell and were subsequently mistaken for showing large white stains. The accuracy of differentiation of the different kinds of dirt stains was 91%. Of the eggs with dark stains, 10.81% were mistaken for having bloodstains, and 33.33% of eggs with bloodstains were mistaken for having dark stains. The developed system is possibly a first step toward an on line dirt evaluation technique for brown eggs.

Configuration color vision tests: the interaction between aging and the complexity of figure-ground segregation.

Science.gov (United States)

Stanford, T; Pollack, R H

1984-09-01

A cross-sectional study comparing response time and the percentage of items correctly identified in three color vision tests (Pflügertrident, HRR-AO pseudoisochromatic plates, and AO pseudoisochromatic plates) was carried out on 72 women (12 in each decade) ranging from ages 20 to 79 years. Overall, time scores increased across the age groups. Analysis of the correctness scores indicated that the AO pseudoisochromatic plates requiring the identification of numbers was more difficult than the other tests which consisted of geometric forms or the letter E. This differential difficulty increased as a function of age. There was no indication of color defect per se which led to the conclusion that figure complexity may be the key variable determining performance. The results were similar to those obtained by Lee and Pollack (1978) in their study of the Embedded Figures Test.

Intelligent color vision system for ripeness classification of oil palm fresh fruit bunch.

Science.gov (United States)

Fadilah, Norasyikin; Mohamad-Saleh, Junita; Abdul Halim, Zaini; Ibrahim, Haidi; Syed Ali, Syed Salim

2012-10-22

Ripeness classification of oil palm fresh fruit bunches (FFBs) during harvesting is important to ensure that they are harvested during optimum stage for maximum oil production. This paper presents the application of color vision for automated ripeness classification of oil palm FFB. Images of oil palm FFBs of type DxP Yangambi were collected and analyzed using digital image processing techniques. Then the color features were extracted from those images and used as the inputs for Artificial Neural Network (ANN) learning. The performance of the ANN for ripeness classification of oil palm FFB was investigated using two methods: training ANN with full features and training ANN with reduced features based on the Principal Component Analysis (PCA) data reduction technique. Results showed that compared with using full features in ANN, using the ANN trained with reduced features can improve the classification accuracy by 1.66% and is more effective in developing an automated ripeness classifier for oil palm FFB. The developed ripeness classifier can act as a sensor in determining the correct oil palm FFB ripeness category.

Intelligent Color Vision System for Ripeness Classification of Oil Palm Fresh Fruit Bunch

Directory of Open Access Journals (Sweden)

Haidi Ibrahim

2012-10-01

Full Text Available Ripeness classification of oil palm fresh fruit bunches (FFBs during harvesting is important to ensure that they are harvested during optimum stage for maximum oil production. This paper presents the application of color vision for automated ripeness classification of oil palm FFB. Images of oil palm FFBs of type DxP Yangambi were collected and analyzed using digital image processing techniques. Then the color features were extracted from those images and used as the inputs for Artificial Neural Network (ANN learning. The performance of the ANN for ripeness classification of oil palm FFB was investigated using two methods: training ANN with full features and training ANN with reduced features based on the Principal Component Analysis (PCA data reduction technique. Results showed that compared with using full features in ANN, using the ANN trained with reduced features can improve the classification accuracy by 1.66% and is more effective in developing an automated ripeness classifier for oil palm FFB. The developed ripeness classifier can act as a sensor in determining the correct oil palm FFB ripeness category.

Craniopharyngioma causing bilateral vision loss 4 months after unremarkable magnetic resonance imaging of the brain

Directory of Open Access Journals (Sweden)

Rainy Betts

2015-01-01

Full Text Available A 65-year-old man developed bilateral vision loss 4 months after magnetic resonance imaging demonstrated no lesion in the vicinity of the optic chiasm, hypothalamus, and suprasellar tissues. Repeat computed tomography 3 months later showed a predominantly cystic mass of the suprasellar cistern with extension into the anterior third ventricle, which histologically was a craniopharyngioma. The clinical course of this case fuels the controversy whether craniopharyngiomas arise from embryonic rests or can be acquired. From a clinical perspective, it raises questions about when to obtain imaging studies dedicated to the chiasm and the appropriate interval in which a scan should be repeated to exclude structural causes of bilateral vision loss.

Pediatric Low Vision

Science.gov (United States)

... Asked Questions Español Condiciones Chinese Conditions Pediatric Low Vision What is Low Vision? Partial vision loss that cannot be corrected causes ... and play. What are the signs of Low Vision? Some signs of low vision include difficulty recognizing ...

Perception of color emotions for single colors in red-green defective observers.

Science.gov (United States)

Sato, Keiko; Inoue, Takaaki

2016-01-01

It is estimated that inherited red-green color deficiency, which involves both the protan and deutan deficiency types, is common in men. For red-green defective observers, some reddish colors appear desaturated and brownish, unlike those seen by normal observers. Despite its prevalence, few studies have investigated the effects that red-green color deficiency has on the psychological properties of colors (color emotions). The current study investigated the influence of red-green color deficiency on the following six color emotions: cleanliness, freshness, hardness, preference, warmth, and weight. Specifically, this study aimed to: (1) reveal differences between normal and red-green defective observers in rating patterns of six color emotions; (2) examine differences in color emotions related to the three cardinal channels in human color vision; and (3) explore relationships between color emotions and color naming behavior. Thirteen men and 10 women with normal vision and 13 men who were red-green defective performed both a color naming task and an emotion rating task with 32 colors from the Berkeley Color Project (BCP). Results revealed noticeable differences in the cleanliness and hardness ratings between the normal vision observers, particularly in women, and red-green defective observers, which appeared mainly for colors in the orange to cyan range, and in the preference and warmth ratings for colors with cyan and purple hues. Similarly, naming errors also mainly occurred in the cyan colors. A regression analysis that included the three cone-contrasts (i.e., red-green, blue-yellow, and luminance) as predictors significantly accounted for variability in color emotion ratings for the red-green defective observers as much as the normal individuals. Expressly, for warmth ratings, the weight of the red-green opponent channel was significantly lower in color defective observers than in normal participants. In addition, the analyses for individual warmth ratings in

Perception of color emotions for single colors in red-green defective observers

Directory of Open Access Journals (Sweden)

Keiko Sato

2016-12-01

Full Text Available It is estimated that inherited red-green color deficiency, which involves both the protan and deutan deficiency types, is common in men. For red-green defective observers, some reddish colors appear desaturated and brownish, unlike those seen by normal observers. Despite its prevalence, few studies have investigated the effects that red-green color deficiency has on the psychological properties of colors (color emotions. The current study investigated the influence of red-green color deficiency on the following six color emotions: cleanliness, freshness, hardness, preference, warmth, and weight. Specifically, this study aimed to: (1 reveal differences between normal and red-green defective observers in rating patterns of six color emotions; (2 examine differences in color emotions related to the three cardinal channels in human color vision; and (3 explore relationships between color emotions and color naming behavior. Thirteen men and 10 women with normal vision and 13 men who were red-green defective performed both a color naming task and an emotion rating task with 32 colors from the Berkeley Color Project (BCP. Results revealed noticeable differences in the cleanliness and hardness ratings between the normal vision observers, particularly in women, and red-green defective observers, which appeared mainly for colors in the orange to cyan range, and in the preference and warmth ratings for colors with cyan and purple hues. Similarly, naming errors also mainly occurred in the cyan colors. A regression analysis that included the three cone-contrasts (i.e., red-green, blue-yellow, and luminance as predictors significantly accounted for variability in color emotion ratings for the red-green defective observers as much as the normal individuals. Expressly, for warmth ratings, the weight of the red-green opponent channel was significantly lower in color defective observers than in normal participants. In addition, the analyses for individual warmth

Conjunction of color and form without attention: evidence from an orientation-contingent color aftereffect.

Science.gov (United States)

Houck, M R; Hoffman, J E

1986-05-01

According to feature-integration theory (Treisman & Gelade, 1980), separable features such as color and shape exist in separate maps in preattentive vision and can be integrated only through the use of spatial attention. Many perceptual aftereffects, however, which are also assumed to reflect the features available in preattentive vision, are sensitive to conjunctions of features. One possible resolution of these views holds that adaptation to conjunctions depends on spatial attention. We tested this proposition by presenting observers with gratings varying in color and orientation. The resulting McCollough aftereffects were independent of whether the adaptation stimuli were presented inside or outside of the focus of spatial attention. Therefore, color and shape appear to be conjoined preattentively, when perceptual aftereffects are used as the measure. These same stimuli, however, appeared to be separable in two additional experiments that required observers to search for gratings of a specified color and orientation. These results show that different experimental procedures may be tapping into different stages of preattentive vision.

NEURORETINITIS : A RARE CASE REPORT OF SUDDEN LOSS OF VISION IN YOUNG ADULT

Directory of Open Access Journals (Sweden)

Padmini

2015-05-01

Full Text Available Neuro retinitis (NR though a rare disease occurring in young adults , mostly unilateral is an inflammatory disorder characterized by swelling of optic nerve head and adjoining retinal nerve fibre layer resulting in a typical Macular star configuration due to lipid exudation within macula and fovea. Neuroretinitis can be due to an infectious process involving the disc , a post viral event , of an autoimmune inflammatory mechanism or sometimes idiopathic in nature resulting in a sudden loss of vision in affected eye along with multiple pupillary defects in form of Anisokoria ( dilated on affected side , Marcus Gunn pupil or ill sustained pupillary reactions . Patients may also present with painful ocular movements mostly adduction and elevation of the eye . Features common to above all 3 groups included age , absence of pain and fundus findings . Preceding systemic symptoms and visual field loss are more common in patient with Cat scratch disease and Multiple Sclerosis and uncommon in those with recurrences . With today’s technological advances , decision making regarding evaluation and treatment of NR is made accurately to reduce the incidence of optic atrophy which leads to total loss of vision

Emerging from Water: Underwater Image Color Correction Based on Weakly Supervised Color Transfer

OpenAIRE

Li, Chongyi; Guo, Jichang; Guo, Chunle

2017-01-01

Underwater vision suffers from severe effects due to selective attenuation and scattering when light propagates through water. Such degradation not only affects the quality of underwater images but limits the ability of vision tasks. Different from existing methods which either ignore the wavelength dependency of the attenuation or assume a specific spectral profile, we tackle color distortion problem of underwater image from a new view. In this letter, we propose a weakly supervised color tr...

Feedback from horizontal cells to cones mediates color induction and may facilitate color constancy in rainbow trout

NARCIS (Netherlands)

Sabbah, Shai; Zhu, Changhai; Hornsby, Mark A. W.; Kamermans, Maarten; Hawryshyn, Craig W.

2013-01-01

Color vision is most beneficial when the visual system is color constant and can correct the excitations of photoreceptors for differences in environmental irradiance. A phenomenon related to color constancy is color induction, where the color of an object shifts away from the color of its

Converting a fluorescence spectrophotometer into a three-channel colorimeter for color vision research

International Nuclear Information System (INIS)

Pardo, P.J.; Perez, A.L.; Suero, M.I.

2004-01-01

An old fluorescence spectrophotometer was recycled to make a three-channel colorimeter. The various modifications involved in its design and implementation are described. An optical system was added that allows the fusion of two visual stimuli coming from the two monochromators of the spectrofluorimeter. Each of these stimuli has a wavelength and bandwidth control, and a third visual stimulus may be taken from a monochromator, a cathode ray tube, a thin film transistor screen, or any other light source. This freedom in the choice of source of the third chromatic channel, together with the characteristics of the visual stimuli from the spectrofluorimeter, give this design a great versatility in its application to novel visual experiments on color vision

Converting a fluorescence spectrophotometer into a three-channel colorimeter for color vision research

Science.gov (United States)

Pardo, P. J.; Pérez, A. L.; Suero, M. I.

2004-01-01

An old fluorescence spectrophotometer was recycled to make a three-channel colorimeter. The various modifications involved in its design and implementation are described. An optical system was added that allows the fusion of two visual stimuli coming from the two monochromators of the spectrofluorimeter. Each of these stimuli has a wavelength and bandwidth control, and a third visual stimulus may be taken from a monochromator, a cathode ray tube, a thin film transistor screen, or any other light source. This freedom in the choice of source of the third chromatic channel, together with the characteristics of the visual stimuli from the spectrofluorimeter, give this design a great versatility in its application to novel visual experiments on color vision.

Role-play facilitates children's mindreading of those with atypical color perception.

Science.gov (United States)

Furumi, Fumikazu; Koyasu, Masuo

2014-01-01

The present study examined the effects of role-play experience on children's mindreading ability. Forty-one primary school children (20 boys, 21 girls, mean age: 9.37 years, range: 8-11 years) were introduced to a communication task in which the use of mindreading was essential. During each trial, participants viewed a shelf, presented on a laptop, which contained several familiar objects, and they were instructed to touch an object on the shelf following an order issued by a "manager" who stood at the opposite side of the shelf. There were two managers: one was a monkey manager with normal color vision, and the other was a dog manager with restricted color vision. The monkey manager could see all the objects in the same colors as the participants, whereas the dog manager saw some objects in different colors. Participants were required to respond according to the manager's instruction. In the restricted color vision condition, the dog manager saw the colors of objects differently; thus, participants had to work out his intentions, according to his different perspective. In the normal color vision condition, all objects were in the same colors as those seen by the monkey manager. Before the test phase, participants in the role-play group were provided a role-play experience in which they assumed the role of the dog manager with restricted color vision. The experimental data were analyzed using a 2 × 2 mixed-design ANOVA (role-play condition × communication partner condition) to examine differences in the error rate. Both main effects and its interaction were significant. According to the post-hoc analyses, participants in the no-role-play condition made significantly more errors in the restricted color vision condition than in the normal color vision condition, whereas no such difference was found among participants in the role-play condition. These results suggest that role-play experience could facilitate mindreading of characters with restricted color vision.

General principles in motion vision: color blindness of object motion depends on pattern velocity in honeybee and goldfish.

Science.gov (United States)

Stojcev, Maja; Radtke, Nils; D'Amaro, Daniele; Dyer, Adrian G; Neumeyer, Christa

2011-07-01

Visual systems can undergo striking adaptations to specific visual environments during evolution, but they can also be very "conservative." This seems to be the case in motion vision, which is surprisingly similar in species as distant as honeybee and goldfish. In both visual systems, motion vision measured with the optomotor response is color blind and mediated by one photoreceptor type only. Here, we ask whether this is also the case if the moving stimulus is restricted to a small part of the visual field, and test what influence velocity may have on chromatic motion perception. Honeybees were trained to discriminate between clockwise- and counterclockwise-rotating sector disks. Six types of disk stimuli differing in green receptor contrast were tested using three different rotational velocities. When green receptor contrast was at a minimum, bees were able to discriminate rotation directions with all colored disks at slow velocities of 6 and 12 Hz contrast frequency but not with a relatively high velocity of 24 Hz. In the goldfish experiment, the animals were trained to detect a moving red or blue disk presented in a green surround. Discrimination ability between this stimulus and a homogenous green background was poor when the M-cone type was not or only slightly modulated considering high stimulus velocity (7 cm/s). However, discrimination was improved with slower stimulus velocities (4 and 2 cm/s). These behavioral results indicate that there is potentially an object motion system in both honeybee and goldfish, which is able to incorporate color information at relatively low velocities but is color blind with higher speed. We thus propose that both honeybees and goldfish have multiple subsystems of object motion, which include achromatic as well as chromatic processing.

Vision, eye disease, and art: 2015 Keeler Lecture.

Science.gov (United States)

Marmor, M F

2016-02-01

The purpose of this study was to examine normal vision and eye disease in relation to art. Ophthalmology cannot explain art, but vision is a tool for artists and its normal and abnormal characteristics may influence what an artist can do. The retina codes for contrast, and the impact of this is evident throughout art history from Asian brush painting, to Renaissance chiaroscuro, to Op Art. Art exists, and can portray day or night, only because of the way retina adjusts to light. Color processing is complex, but artists have exploited it to create shimmer (Seurat, Op Art), or to disconnect color from form (fauvists, expressionists, Andy Warhol). It is hazardous to diagnose eye disease from an artist's work, because artists have license to create as they wish. El Greco was not astigmatic; Monet was not myopic; Turner did not have cataracts. But when eye disease is documented, the effects can be analyzed. Color-blind artists limit their palette to ambers and blues, and avoid greens. Dense brown cataracts destroy color distinctions, and Monet's late canvases (before surgery) showed strange and intense uses of color. Degas had failing vision for 40 years, and his pastels grew coarser and coarser. He may have continued working because his blurred vision smoothed over the rough work. This paper can barely touch upon the complexity of either vision or art. However, it demonstrates some ways in which understanding vision and eye disease give insight into art, and thereby an appreciation of both art and ophthalmology.

78 FR 12815 - Qualification of Drivers; Exemption Applications; Vision

Science.gov (United States)

2013-02-25

.... The best corrected visual acuity in his right eye is light perception, and in his left eye, 20/20.... Lifelong. Stable. Visual fields WNL. Color WNL. No contraindications for commercial driving.'' Mr. Clark... color vision, 180 degrees of peripheral vision, no medical contraindication to commercial truck driving...

[Web-based analysis of Stilling's color plates].

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Kuchenbecker, J

2014-12-01

Color vision tests with pseudoisochromatic plates currently represent the most common procedure for the screening of congenital color vision deficiencies. By means of a web-based color vision test, new and old color plates can be tested for diagnostic quality without major effort. A total of 16 digitized Stilling's color plates of the 11th edition from 1907 were included in a web-based color vision test (http://www.farbsehtest.de). The χ(2)-test was used to check whether the Stilling color plates showed similar results to the nine previously evaluated Ishihara color plates. A total of 518 subjects including101 (19.5 %) female subjects with a mean age of 34.6 ± 17 years, took the web-based test with the 25 plates. For all participants the range for the correctly recognized plates was between 5.2 % (n = 27) and 97.7 % (n = 506) for the Stilling color plates and between 64.9 % (n = 336) and 100 % (n = 518) for the Ishihara color plates. For participants with more than 5 errors (n = 247), the range for correctly recognized plates was between 2.0 % (n = 5) and 98.0 % (n = 242) for the Stilling plates and between 42.5 % (n = 105) and 100 % (n = 247) for the Ishihara plates. Taking all color plates and all participants into account there was a significantly higher incidence of erroneous recognition of the Stilling color plates (3038 false and 5250 true answers) compared to the Ishihara color plates (1511 false and 3151 true answers) (p plates could be used for the test edition of the Velhagen/Broschmann/Kuchenbecker color plates from 2014. Overall, the Stilling color plates were recognized with a higher incidence of error by all participants in the web-based test compared to the utilized Ishihara color plates, which in most cases was attributable to ambiguity of some symbols.

Colored Contact Lens Dangers

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Full Text Available ... lentes de contacto de color Sep. 26, 2013 It started as an impulsive buy from a souvenir ... Can Ruin Vision Eye Makeup Safety In fact, it is illegal to sell colored contact lenses without ...

Role-play facilitates children’s mindreading of those with atypical color perception

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Fumikazu eFurumi

2014-07-01

Full Text Available The present study examined the effects of role-play experience on children’s mindreading ability. Forty-one primary school children (20 boys, 21 girls, mean age: 9.37 years, range: 8–11 years were introduced to a communication task in which the use of mindreading was essential. During each trial, participants viewed a shelf, presented on a laptop, which contained several familiar objects, and they were instructed to touch an object on the shelf following an order issued by a manager who stood at the opposite side of the shelf. There were two managers: one was a monkey manager with normal color vision, and the other was a dog manager with restricted color vision. The monkey manager could see all the objects in the same colors as the participants, whereas the dog manager saw some objects in different colors. Participants were required to respond according to the manager's instruction. In the restricted color vision condition, the dog manager saw the colors of objects differently; thus, participants had to work out his intentions, according to his different perspective. In the normal color vision condition, all objects were in the same colors as those seen by the monkey manager. Before the test phase, participants in the role-play group were provided a role-play experience in which they assumed the role of the dog manager with restricted color vision. The experimental data were analyzed using a 2 x 2 mixed-design ANOVA (role-play condition x communication partner condition to examine differences in the error rate. Both main effects and its interaction were significant. According to the post-hoc analyses, participants in the no-role-play condition made significantly more errors in the restricted color vision condition than in the normal color vision condition, whereas no such difference was found among participants in the role-play condition. These results suggest that role-play experience could facilitate mindreading of characters with

Adjustment to acquired vision loss in adults presenting for visual disability certification

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Aditya Nakade

2017-01-01

Full Text Available Context: Rehabilitation of the visually disabled depends on how they adjust to loss; understanding contributing factors may help in effective rehabilitation. Aim: The aim of this study is to assess adjustment to acquired vision loss in adults. Settings and Design: This observational study, conducted in the Department of Ophthalmology at a tertiary-level teaching hospital, included thirty persons (25–65 years with <6/60 in the better eye, and vision loss since ≥6-months. Materials and Methods: Age, gender, rural/urban residence, education, current occupation, binocular distance vision, adjustment (Acceptance and Self-Worth Adjustment Scale, depression (Center for Epidemiologic Studies-Depression Scale, social support (Duke Social Support and Stress Scale, and personality (10-item Personality Inventory scale was recorded. Statistical Analysis: To determine their effect on adjustment, Student's t-test was used for categorical variables, Pearson's correlation for age, and Spearman's correlation for depression, personality trait and social support and stress. Results: Of 30 persons recruited, 24 were men (80%; 24 lived in urban areas (80%; 9 were employed (30%; and 14 (46.6% had studied < Class 3. Adjustment was low (range: 33%–60%; mean: 43.6 ± 5.73. Reported support was low (median: 27.2; interquartile range [IQR]: 18.1–36.3; reported stress was low (median: 0.09; IQR: 0–18.1. Predominant personality traits (max score 14 were “Agreeableness” (average 12.0 ± 1.68 and “Conscientiousness” (average 11.3 ± 2.12. Emotional stability (average 9.2 ± 2.53 was less prominent. Depression score ranged from 17 to 50 (average 31.6 ± 6.01. The factors studied did not influence adjustment. Conclusions: Although adjustment did not vary with factors studied, all patients were depressed. Since perceived support and emotional stability was low, attention could be directed to support networks. Training patients in handling emotions, and training

Spatial updating depends on gaze direction even after loss of vision.

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Reuschel, Johanna; Rösler, Frank; Henriques, Denise Y P; Fiehler, Katja

2012-02-15

Direction of gaze (eye angle + head angle) has been shown to be important for representing space for action, implying a crucial role of vision for spatial updating. However, blind people have no access to vision yet are able to perform goal-directed actions successfully. Here, we investigated the role of visual experience for localizing and updating targets as a function of intervening gaze shifts in humans. People who differed in visual experience (late blind, congenitally blind, or sighted) were briefly presented with a proprioceptive reach target while facing it. Before they reached to the target's remembered location, they turned their head toward an eccentric direction that also induced corresponding eye movements in sighted and late blind individuals. We found that reaching errors varied systematically as a function of shift in gaze direction only in participants with early visual experience (sighted and late blind). In the late blind, this effect was solely present in people with moveable eyes but not in people with at least one glass eye. Our results suggest that the effect of gaze shifts on spatial updating develops on the basis of visual experience early in life and remains even after loss of vision as long as feedback from the eyes and head is available.

P1-15: Categorical Color Perception of LED Illuminant Color for Deuteranomals

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Saeko Oishi

2012-10-01

Full Text Available Color information has great value in our everyday lives, but it is not mindful of people with color vision deficiency (CVD. We can choose several color names to categorize a lot of colors around us. Eleven color names (white, black, red, green, yellow, blue, brown, orange, pink, and gray are known as basic color categories, but people with CVD cannot necessarily describe colors as people who are color vision normal (CVN do. Previous studies showed that it was hard for people with CVD to discriminate illuminant color from object color, and their color perception changed largely depending on experimental conditions. In this study we investigated categorical color perception of illuminant color for deuteranomals, using a mixture of light which consists of a red, a green, and a blue LED as a test stimulus. We tested those stimuli with three luminance levels (180 cd/m2, 18 cd/m2, 1.8 cd/m2 and two visual angles (10 deg, 0.5 deg. Subjects were three deuteranomals and three people who are CVN. Our result showed that the categorical color of mild deuteranomals was similar to that of those who were CVN, but that of severe deuteranomals was not. Severe deuteranomals judged more low chromatic colors as achromatic colors than those who were CVN. The smaller visual angle or lower luminance level the test stimulus had, the more deuteranomals confused color. The results suggest that the effect of the Bezold-Brucke phenomenon is greater to deuteranomals than to those who are CVN. Furthermore, deuteranomals use not only chromatic information but also luminance information when they describe color.

Impairments to Vision

Science.gov (United States)

... an external Non-Government web site. Impairments to Vision Normal Vision Diabetic Retinopathy Age-related Macular Degeneration In this ... pictures, fixate on the nose to simulate the vision loss. In diabetic retinopathy, the blood vessels in ...

Rescue of cell death and inflammation of a mouse model of complex 1-mediated vision loss by repurposed drug molecules.

Science.gov (United States)

Yu, Alfred K; Datta, Sandipan; McMackin, Marissa Z; Cortopassi, Gino A

2017-12-15

Inherited mitochondrial optic neuropathies, such as Leber's hereditary optic neuropathy (LHON) and Autosomal dominant optic atrophy (ADOA) are caused by mutant mitochondrial proteins that lead to defects in mitochondrial complex 1-driven ATP synthesis, and cause specific retinal ganglion cell (RGC) loss. Complex 1 defects also occur in patients with primary open angle glaucoma (POAG), in which there is specific RGC loss. The treatment of mitochondrial optic neuropathy in the US is only supportive. The Ndufs4 knockout (Ndufs4 KO) mouse is a mitochondrial complex 1-deficient model that leads to RGC loss and rapid vision loss and allows for streamlined testing of potential therapeutics. Preceding RGC loss in the Ndufs4 KO is the loss of starburst amacrine cells, which may be an important target in the mechanism of complex 1-deficient vision loss. Papaverine and zolpidem were recently shown to be protective of bioenergetic loss in cell models of optic neuropathy. Treatment of Ndufs4 KO mice with papaverine, zolpidem, and rapamycin-suppressed inflammation, prevented cell death, and protected from vision loss. Thus, in the Ndufs4 KO mouse model of mitochondrial optic neuropathy, papaverine and zolpidem provided significant protection from multiple pathophysiological features, and as approved drugs in wide human use could be considered for the novel indication of human optic neuropathy. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

An unusual complication of combined gonioscopy-assisted transluminal trabeculotomy and phacoemulsification: vision loss due to intracapsular hematoma.

Science.gov (United States)

Yalinbas, Duygu; Aktas, Zeynep; Hepsen, İbrahim; Dilekmen, Nilay

2017-09-23

To report two cases with an acute vision loss due to intracapsular hemorrhage (hematoma) after an uncomplicated gonioscopy-assisted transluminal trabeculotomy (GATT) combined with phacoemulsification surgery. Case report. Seventy-six-year-old male and 75-year-old female patients with cataract and pseudoexfoliative glaucoma (XFG) uncontrolled with maximum medical therapy both underwent GATT combined with phacoemulsification. Shortly after the surgery, intracapsular hematoma behind the intraocular lens (IOL) were noted in both patients. Hematoma cleared in both of them via IOL extraction-anterior vitrectomy and YAG-laser capsulotomy, respectively. Hematoma cleared in both patients without any surgical complications. Vision loss due to unclearing intracapsular hematoma might be an early complication of combined GATT and phacoemulsification surgery.

Cardiorespiratory fitness and vision loss among young and middle-age U.S. adults.

Science.gov (United States)

Loprinzi, Paul D; Zebardast, Nazlee; Ramulu, Pradeep Y

2015-01-01

To examine the association between vision loss and cardiorespiratory fitness among young and middle-age U.S. adults. The study had a cross-sectional design. The National Health and Nutrition Examination Survey 1999-2004 served as the study setting. Study subjects included 3135 adults ages 20 to 49 years. Cardiorespiratory fitness was assessed from cardiorespiratory extrapolation using heart rate response during submaximal treadmill testing, with inadequate cardiorespiratory fitness defined as below the 60th percentile for age and gender. Visual acuity was objectively assessed for each eye. Multivariable regression (linear and logistic) models were computed to examine the association between cardiorespiratory fitness and vision. Poorer cardiorespiratory fitness (β = -3.7 mL O2/kg per minute; 95% confidence interval: -5.3 to -2.2) was observed in subjects with visual impairment after adjusting for age, gender, race/ethnicity, and comorbid illness. Participants with vision impairment, as compared with those with normal sight, had 4.4-fold higher odds of having inadequate cardiorespiratory fitness (95% confidence interval: 1.04-18.97), whereas participants with uncorrected refractive error were not more likely to demonstrate poorer cardiorespiratory fitness. Adults with visual impairment, but not adults with uncorrected refractive error, demonstrate a significant reduction in cardiorespiratory fitness and are much more likely to have inadequate fitness compared with those with normal vision. Evaluation and implementation of strategies to increase cardiorespiratory fitness among those with vision impairment, in particular, are needed.

The role of vision processing in prosthetic vision.

Science.gov (United States)

Barnes, Nick; He, Xuming; McCarthy, Chris; Horne, Lachlan; Kim, Junae; Scott, Adele; Lieby, Paulette

2012-01-01

Prosthetic vision provides vision which is reduced in resolution and dynamic range compared to normal human vision. This comes about both due to residual damage to the visual system from the condition that caused vision loss, and due to limitations of current technology. However, even with limitations, prosthetic vision may still be able to support functional performance which is sufficient for tasks which are key to restoring independent living and quality of life. Here vision processing can play a key role, ensuring that information which is critical to the performance of key tasks is available within the capability of the available prosthetic vision. In this paper, we frame vision processing for prosthetic vision, highlight some key areas which present problems in terms of quality of life, and present examples where vision processing can help achieve better outcomes.

Diagnosis System for Diabetic Retinopathy and Glaucoma Screening to Prevent Vision Loss

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Siva Sundhara Raja DHANUSHKODI

2014-03-01

Full Text Available Aim: Diabetic retinopathy (DR and glaucoma are two most common retinal disorders that are major causes of blindness in diabetic patients. DR caused in retinal images due to the damage in retinal blood vessels, which leads to the formation of hemorrhages spread over the entire region of retina. Glaucoma is caused due to hypertension in diabetic patients. Both DR and glaucoma affects the vision loss in diabetic patients. Hence, a computer aided development of diagnosis system for Diabetic retinopathy and Glaucoma screening is proposed in this paper to prevent vision loss. Method: The diagnosis system of DR consists of two stages namely detection and segmentation of fovea and hemorrhages. The diagnosis system of glaucoma screening consists of three stages namely blood vessel segmentation, Extraction of optic disc (OD and optic cup (OC region and determination of rim area between OD and OC. Results: The specificity and accuracy for hemorrhages detection is found to be 98.47% and 98.09% respectively. The accuracy for OD detection is found to be 99.3%. This outperforms state-of-the-art methods. Conclusion: In this paper, the diagnosis system is developed to classify the DR and glaucoma screening in to mild, moderate and severe respectively.

Neuropharmacology of vision in goldfish: a review.

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Mora-Ferrer, Carlos; Neumeyer, Christa

2009-05-01

The goldfish is one of the few animals exceptionally well analyzed in behavioral experiments and also in electrophysiological and neuroanatomical investigations of the retina. To get insight into the functional organization of the retina we studied color vision, motion detection and temporal resolution before and after intra-ocular injection of neuropharmaca with known effects on retinal neurons. Bicuculline, strychnine, curare, atropine, and dopamine D1- and D2-receptor antagonists were used. The results reviewed here indicate separate and parallel processing of L-cone contribution to different visual functions, and the influence of several neurotransmitters (dopamine, acetylcholine, glycine, and GABA) on motion vision, color vision, and temporal resolution.

Developmental Regulation with Progressive Vision Loss: Use of Control Strategies and Affective Well-Being

Science.gov (United States)

Schilling, Oliver K.; Wahl, Hans-Werner; Boerner, Kathrin; Horowitz, Amy; Reinhardt, Joann P.; Cimarolli, Verena R.; Brennan-Ing, Mark; Heckhausen, Jutta

2016-01-01

The present study addresses older adults' developmental regulation when faced with progressive and irreversible vision loss. We used the motivational theory of life span development as a conceptual framework and examined changes in older adults' striving for control over everyday goal achievement, and their association with affective well-being,…

Color blindness among multiple sclerosis patients in Isfahan.

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Shaygannejad, Vahid; Golabchi, Khodayar; Dehghani, Alireza; Ashtari, Fereshteh; Haghighi, Sepehr; Mirzendehdel, Mahsa; Ghasemi, Majid

2012-03-01

Multiple sclerosis (MS) is a disease of young and middle aged individuals with a demyelinative axonal damage nature in central nervous system that causes various signs and symptoms. As color vision needs normal function of optic nerve and macula, it is proposed that MS can alter it via influencing optic nerve. In this survey, we evaluated color vision abnormalities and its relationship with history of optic neuritis and abnormal visual evoked potentials (VEPs) among MS patients. The case group was included of clinically definitive MS patients and the same number of normal population was enrolled as the control group. Color vision of all the participants was evaluated by Ishihara test and then visual evoked potential (VEPs) and history of optic neuritis (ON) was assessed among them. Then, frequency of color blindness was compared between the case and the control group. Finally, color blinded patients were compared to those with the history of ON and abnormal VEPs. 63 MS patients and the same number of normal populations were enrolled in this study. 12 patients had color blindness based on the Ishihara test; only 3 of them were among the control group, which showed a significant different between the two groups (P = 0.013). There was a significant relationship between the color blindness and abnormal VEP (R = 0.53, P = 0.023) but not for the color blindness and ON (P = 0.67). This study demonstrates a significant correlation between color blindness and multiple sclerosis including ones with abnormal prolonged VEP latencies. Therefore, in individuals with acquired color vision impairment, an evaluation for potentially serious underlying diseases like MS is essential.

Color blindness among multiple sclerosis patients in Isfahan

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Vahid Shaygannejad

2012-01-01

Full Text Available Background: Multiple sclerosis (MS is a disease of young and middle aged individuals with a demyelinative axonal damage nature in central nervous system that causes various signs and symptoms. As color vision needs normal function of optic nerve and macula, it is proposed that MS can alter it via influencing optic nerve. In this survey, we evaluated color vision abnormalities and its relationship with history of optic neuritis and abnormal visual evoked potentials (VEPs among MS patients. Materials and Methods: The case group was included of clinically definitive MS patients and the same number of normal population was enrolled as the control group. Color vision of all the participants was evaluated by Ishihara test and then visual evoked potential (VEPs and history of optic neuritis (ON was assessed among them. Then, frequency of color blindness was compared between the case and the control group. Finally, color blinded patients were compared to those with the history of ON and abnormal VEPs. Results: 63 MS patients and the same number of normal populations were enrolled in this study. 12 patients had color blindness based on the Ishihara test; only 3 of them were among the control group, which showed a significant different between the two groups (P = 0.013. There was a significant relationship between the color blindness and abnormal VEP (R = 0.53, P = 0.023 but not for the color blindness and ON (P = 0.67. Conclusions: This study demonstrates a significant correlation between color blindness and multiple sclerosis including ones with abnormal prolonged VEP latencies. Therefore, in individuals with acquired color vision impairment, an evaluation for potentially serious underlying diseases like MS is essential.

Loss of Color by Afterimage Masking

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Kohske Takahashi

2013-05-01

Full Text Available When two images, one depicting colored disks and the other depicting colored windmill patterns, are displayed in succession, the color of the windmills is perceptually replaced by black. The illusion is striking. Experiments confirmed (1 that the luminance contrast between the target patterns and the background must be large and (2 that the disks and windmills must be static on the retina and in register. The illusion is weakened when the windmills and disks have different colors.

[The evaluation of color vision and its diagnostic value in predicting the risk of diabetic retinopathy in patients with glucose metabolism disorders].

Science.gov (United States)

Jończyk-Skórka, Katarzyna; Kowalski, Jan

2017-07-21

The aim of the study was to evaluate color vision and its diagnostic value in predicting the risk of diabetic retinopathy in patients with glucose metabolism disorders. The study involved 197 people, 92 women and 105 men aged 63.21 ± 8.74 years. In order to assess glucose metabolism disorders, patients were divided into three groups. The first group (DM) consisted of 60 people (16 women and 44 men aged 61.92 ± 8.46 years). These were people with type 2 diabetes. Second group (IFG IGT) consisted of 67 people (35 women and 32 men aged 65 ± 8.5 years). These were people who were diagnosed with impaired fasting glucose or impaired glucose tolerance. The third group, the control one (K) consisted of 70 people (41 women and 29 men aged 62.6 ± 9.06 years). They were healthy individuals. In order to assess diabetic retinopathy study population was divided into two groups. The first group (BZ) consisted of 177 patients (84 women and 93 men aged 62.9 ± 8.78 years) without diabetic retinopathy. The second group (NPDR) consisted of 20 patients (8 women and 12 men aged 65.95 ± 8.17 years) with diabetic retinopathy. Glucose metabolism disorders were diagnosed with glucose tolerance test (OGTT). Evaluation of retinopathy was based on eye examination. All patients underwent binocular Farnsworth-Munsell 100 Hue color vision test (test result is a Total Error Score - TES). In the healthy control group (K) there were less patients with diabetic retinopathy (p = 0,0101), and less patients with abnormal color vision test (p = 0,0001) than in other groups. Majority of patients in K group had generalized abnormalities of color vision while other groups demonstrated tritanomalią (p = 0,0018). It was discovered that sTES value adequately distinguishes group K from group IFG, IGT, DM (AUC = 0,673), group K from group DM (AUC = 0,701), and group K from group IFG IGT (AUC = 0,648) sTES does not differentiate groups IGT, IFG and DM (AUC = 0,563). It was shown that in IGT, IFG group s

Multi-capability color night vision HD camera for defense, surveillance, and security

Science.gov (United States)

Pang, Francis; Powell, Gareth; Fereyre, Pierre

2015-05-01

e2v has developed a family of high performance cameras based on our next generation CMOS imagers that provide multiple features and capabilities to meet the range of challenging imaging applications in defense, surveillance, and security markets. Two resolution sizes are available: 1920x1080 with 5.3 μm pixels, and an ultra-low light level version at 1280x1024 with 10μm pixels. Each type is available in either monochrome or e2v's unique bayer pattern color version. The camera is well suited to accommodate many of the high demands for defense, surveillance, and security applications: compact form factor (SWAP+C), color night vision performance (down to 10-2 lux), ruggedized housing, Global Shutter, low read noise (<6e- in Global shutter mode and <2.5e- in Rolling shutter mode), 60 Hz frame rate, high QE especially in the enhanced NIR range (up to 1100nm). Other capabilities include active illumination and range gating. This paper will describe all the features of the sensor and the camera. It will be followed with a presentation of the latest test data with the current developments. Then, it will conclude with a description of how these features can be easily configured to meet many different applications. With this development, we can tune rather than create a full customization, making it more beneficial for many of our customers and their custom applications.

Neuropathies of the optic nerve and visual evoked potentials with special reference to color vision and differential light threshold measured with the computer perimeter OCTOPUS.

Science.gov (United States)

Wildberger, H

1984-10-31

The contrast evoked potentials (VEPs) to different check sizes were recorded in about 200 cases of discrete optic neuropathies (ON) of different origin. Differential light threshold (DLT) was tested with the computer perimeter OCTOPUS. Saturated and desaturated tests were applied to evaluate the degree of acquired color vision deficiency. Delayed VEP responses are not confined to optic neuritis (RBN) alone and the different latency times obtained from other ON are confluent. The delay may be due to demyelination, to an increasing dominance of paramacular VEP subcomponents or to an increasing dominance of the upper half-field responses. Recording with smaller check sizes has the advantage that discrete dysfunctions in the visual field (VF) center are more easily detected: a correlation between amplitudes and visual acuity is best in strabismic amblyopias, is less expressed in maculopathies of the retina and weak in ON. The absence or reduction of amplitudes to smaller check sizes, however, is an important indication of a disorder in the VF center of ON in an early or recovered stage. Acquired color vision defects of the tritan-like type are more confined to discrete ON, whereas the red/green type is reserved to more severe ON. The DLT of the VF center is reduced in a different, significant and non significant extent in discrete optic neuropathies and the correlation between DLT and visual acuity is weak. A careful numerical analysis is needed in types of discrete ON where the central DLT lies within normal statistical limits: a side difference of the DLT between the affected and the normal fellow eye is always present. Evaluation of visual fatigue effects and of the relative sensitivity loss of VF center and VF periphery may provide further diagnostic information.

Dural metastasis from prostatic adenocarcinoma mimicking meningioma: Report of a case with unilateral loss of vision

International Nuclear Information System (INIS)

Tokgoz, Ozlem; Voyvoda, Nuray; Tokgoz, Husnu

2011-01-01

We report a case of PCa (prostatic adenocarcinoma) with transdural metastasis which radiologically simulated a meningioma. During the course of the disease, the patient complained of progressive unilateral loss of vision as the first presentation of intracranial, extra-axial metastasis

Image Transform Based on the Distribution of Representative Colors for Color Deficient

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Ohata, Fukashi; Kudo, Hiroaki; Matsumoto, Tetsuya; Takeuchi, Yoshinori; Ohnishi, Noboru

This paper proposes the method to convert digital image containing distinguishing difficulty sets of colors into the image with high visibility. We set up four criteria, automatically processing by a computer, retaining continuity in color space, not making images into lower visible for people with normal color vision, and not making images not originally having distinguishing difficulty sets of colors into lower visible. We conducted the psychological experiment. We obtained the result that the visibility of a converted image had been improved at 60% for 40 images, and we confirmed the main criterion of the continuity in color space was kept.

An Investigation of the Effects of Practice on Color Memory as a Function of Condition, Dimension and Color

OpenAIRE

Remus, Britten Grace

2001-01-01

Forty-two college aged participants took part in a mixed repeated measures factorial design experiment that assessed color memory as a function of condition (practice with feedback, practice without feedback and no practice), dimension (hue, saturation and lightness) and color (red, yellow, green and blue). Attention was focused on the distinction between memory color and color memory, color experience and preference, mechanisms of color perception and theories of color vision (see below). ...

Industrial Color Physics

CERN Document Server

Klein, Georg A

2010-01-01

This unique book starts with a short historical overview of the development of the theories of color vision and applications of industrial color physics. The three dominant factors producing color - light source, color sample, and observer - are described in detail. The standardized color spaces are shown and related color values are applied to characteristic color qualities of absorption as well as of effect colorants. The fundamentals of spectrometric and colorimetric measuring techniques together with specific applications are described. Theoretical models for radiative transfer in transparent, translucent, and opaque layers are detailed; the two, three, and multi-flux approximations are presented for the first time in a coherent formalism. These methods constitute the fundamentals not only for the important classical methods, but also modern methods of recipe prediction applicable to all known colorants. The text is supplied with 52 tables, more than 200 partially colored illustrations, an appendix, and a...

Color vision versus pattern visual evoked potentials in the assessment of subclinical optic pathway involvement in multiple sclerosis

Directory of Open Access Journals (Sweden)

Fatih C Gundogan

2013-01-01

Full Text Available Background: Optic pathway involvement in multiple sclerosis is frequently the initial sign in the disease process. In most clinical applications, pattern visual evoked potential (PVEP is used in the assessment of optic pathway involvement. Objective: To question the value of PVEP against color vision assessment in the diagnosis of subclinical optic pathway involvement. Materials and Methods: This prospective, cross-sectional study included 20 multiple sclerosis patients without a history of optic neuritis, and 20 healthy control subjects. Farnsworth-Munsell (FM 100-Hue testing and PVEPs to 60-min arc and 15-min arc checks by using Roland-Consult RetiScan® system were performed. P 100 amplitude, P 100 latency in PVEP and total error scores (TES in FM 100-Hue test were assessed. Results: Expanded Disability Status Scale score and the time from diagnosis were 2.21 ± 2.53 (ranging from 0 to 7 and 4.1 ± 4.4 years. MS group showed significantly delayed P 100 latency for both checks (P 0.05 for all. 14 MS patients (70% had an increased TESs in FM-100 Hue, 11 (55% MS patients had delayed P 100 latency and 9 (45% had reduced P 100 amplitude. The areas under the ROC curves were 0.944 for FM-100 Hue test, 0.753 for P 100 latency, and 0.173 for P 100 amplitude. Conclusions: Color vision testing seems to be more sensitive than PVEP in detecting subclinical visual pathway involvement in MS.

Visual system plasticity in mammals: the story of monocular enucleation-induced vision loss

Science.gov (United States)

Nys, Julie; Scheyltjens, Isabelle; Arckens, Lutgarde

2015-01-01

The groundbreaking work of Hubel and Wiesel in the 1960’s on ocular dominance plasticity instigated many studies of the visual system of mammals, enriching our understanding of how the development of its structure and function depends on high quality visual input through both eyes. These studies have mainly employed lid suturing, dark rearing and eye patching applied to different species to reduce or impair visual input, and have created extensive knowledge on binocular vision. However, not all aspects and types of plasticity in the visual cortex have been covered in full detail. In that regard, a more drastic deprivation method like enucleation, leading to complete vision loss appears useful as it has more widespread effects on the afferent visual pathway and even on non-visual brain regions. One-eyed vision due to monocular enucleation (ME) profoundly affects the contralateral retinorecipient subcortical and cortical structures thereby creating a powerful means to investigate cortical plasticity phenomena in which binocular competition has no vote.In this review, we will present current knowledge about the specific application of ME as an experimental tool to study visual and cross-modal brain plasticity and compare early postnatal stages up into adulthood. The structural and physiological consequences of this type of extensive sensory loss as documented and studied in several animal species and human patients will be discussed. We will summarize how ME studies have been instrumental to our current understanding of the differentiation of sensory systems and how the structure and function of cortical circuits in mammals are shaped in response to such an extensive alteration in experience. In conclusion, we will highlight future perspectives and the clinical relevance of adding ME to the list of more longstanding deprivation models in visual system research. PMID:25972788

Curing Color Blindness—Mice and Nonhuman Primates

Science.gov (United States)

Neitz, Maureen; Neitz, Jay

2014-01-01

It has been possible to use viral-mediated gene therapy to transform dichromatic (red-green color-blind) primates to trichromatic. Even though the third cone type was added after the end of developmental critical periods, treated animals acquired red-green color vision. What happened in the treated animals may represent a recapitulation of the evolution of trichromacy, which seems to have evolved with the acquisition of a third cone type without the need for subsequent modification to the circuitry. Some transgenic mice in which a third cone type was added also acquired trichromacy. However, compared with treated primates, red-green color vision in mice is poor, indicating large differences between mice and monkeys in their ability to take advantage of the new input. These results have implications for understanding the limits and opportunities for using gene therapy to treat vision disorders caused by defects in cone function. PMID:25147187

75 FR 9480 - Qualification of Drivers; Exemption Applications; Vision

Science.gov (United States)

2010-03-02

... injury sustained as a child. The best corrected visual acuity in his right eye is light-perception only... medical opinion, Mr. Williford has sufficient visual acuity, color vision and peripheral vision to perform...

Low Vision Rehabilitation and Diabetic Retinopathy

International Nuclear Information System (INIS)

Khan, Sarfaraz A.

2007-01-01

Diabetic retinopathy is emerging as a major cause of blindness. Diabetic retinopathy calls for a multidisciplinary to the patients. Management of the patient requires a team work by the internist, diabetologist, dietician, ophthalmologist and low vision therapist. Diabetic retinopathy very often results in vision loss. It is important for ophthalmologist to recognize the importance of low vision rehabilitation in formulating appropriate treatment strategies. People with low vision loss due to diabetic retinopathy usually experience difficulty in daily life. Most people with diabetic retinopathy (who have remaining useful vision) can be helped with low vision devices. However, often one low vision device may not be suitable for all purposes. A comprehensive low vision evaluation is required to assess the person's current visual status, identify the goals and the visual needs, and then design an individualized vision rehabilitation program to meet these needs. (author)

Monitoring Hydration Status Pre- and Post-Training among University Athletes Using Urine Color and Weight Loss Indicators

Science.gov (United States)

Webb, Marquitta C.; Salandy, Sinead T.; Beckford, Safiya E.

2016-01-01

Objective: To investigate the hydration status pre- and post-training among university athletes using urine color and weight loss as indicators. Participants: Participants were 52 university athletes training for campus games in a developing country. Methods: Pre- and post-training urine specimens were compared with a standard urine color scale.…

Dietary Approaches to Protect Against Eye Blast Induced Oxidative Stress and Vision Loss

Science.gov (United States)

2016-11-01

type (C57Bl/6) and Gulo-/- mice maintained on normal or low vitamin C. C, D ) MDA levels in the A) cortex and B) liver of Gulo-/- mice maintained...significantly to the progressive cell death and neuronal degeneration that we detect after ocular trauma and, thus, treating with Vitamins C and E or a...we may have identified IL-1 as an important mediator of vision loss after ocular trauma. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17

Visual wetness perception based on image color statistics.

Science.gov (United States)

Sawayama, Masataka; Adelson, Edward H; Nishida, Shin'ya

2017-05-01

Color vision provides humans and animals with the abilities to discriminate colors based on the wavelength composition of light and to determine the location and identity of objects of interest in cluttered scenes (e.g., ripe fruit among foliage). However, we argue that color vision can inform us about much more than color alone. Since a trichromatic image carries more information about the optical properties of a scene than a monochromatic image does, color can help us recognize complex material qualities. Here we show that human vision uses color statistics of an image for the perception of an ecologically important surface condition (i.e., wetness). Psychophysical experiments showed that overall enhancement of chromatic saturation, combined with a luminance tone change that increases the darkness and glossiness of the image, tended to make dry scenes look wetter. Theoretical analysis along with image analysis of real objects indicated that our image transformation, which we call the wetness enhancing transformation, is consistent with actual optical changes produced by surface wetting. Furthermore, we found that the wetness enhancing transformation operator was more effective for the images with many colors (large hue entropy) than for those with few colors (small hue entropy). The hue entropy may be used to separate surface wetness from other surface states having similar optical properties. While surface wetness and surface color might seem to be independent, there are higher order color statistics that can influence wetness judgments, in accord with the ecological statistics. The present findings indicate that the visual system uses color image statistics in an elegant way to help estimate the complex physical status of a scene.

An Adaptive Fuzzy-Based System to Simulate, Quantify and Compensate Color Blindness

OpenAIRE

Lee, Jinmi; Santos, Wellington Pinheiro dos

2017-01-01

About 8% of the male population of the world are affected by a determined type of color vision disturbance, which varies from the partial to complete reduction of the ability to distinguish certain colors. A considerable amount of color blind people are able to live all life long without knowing they have color vision disabilities and abnormalities. Nowadays the evolution of information technology and computer science, specifically image processing techniques and computer graphics, can be fun...

Braille Reading Accuracy of Students Who Are Visually Impaired: The Effects of Gender, Age at Vision Loss, and Level of Education

Science.gov (United States)

Argyropoulos, Vassilis; Papadimitriou, Vassilios

2015-01-01

Introduction: The present study assesses the performance of students who are visually impaired (that is, those who are blind or have low vision) in braille reading accuracy and examines potential correlations among the error categories on the basis of gender, age at loss of vision, and level of education. Methods: Twenty-one visually impaired…

Realtime Color Stereovision Processing

National Research Council Canada - National Science Library

Formwalt, Bryon

2000-01-01

.... This research takes a step forward in real time machine vision processing. It investigates techniques for implementing a real time stereovision processing system using two miniature color cameras...

Curing color blindness--mice and nonhuman primates.

Science.gov (United States)

Neitz, Maureen; Neitz, Jay

2014-08-21

It has been possible to use viral-mediated gene therapy to transform dichromatic (red-green color-blind) primates to trichromatic. Even though the third cone type was added after the end of developmental critical periods, treated animals acquired red-green color vision. What happened in the treated animals may represent a recapitulation of the evolution of trichromacy, which seems to have evolved with the acquisition of a third cone type without the need for subsequent modification to the circuitry. Some transgenic mice in which a third cone type was added also acquired trichromacy. However, compared with treated primates, red-green color vision in mice is poor, indicating large differences between mice and monkeys in their ability to take advantage of the new input. These results have implications for understanding the limits and opportunities for using gene therapy to treat vision disorders caused by defects in cone function. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.

A child's vision.

Science.gov (United States)

Nye, Christina

2014-06-01

Implementing standard vision screening techniques in the primary care practice is the most effective means to detect children with potential vision problems at an age when the vision loss may be treatable. A critical period of vision development occurs in the first few weeks of life; thus, it is imperative that serious problems are detected at this time. Although it is not possible to quantitate an infant's vision, evaluating ocular health appropriately can mean the difference between sight and blindness and, in the case of retinoblastoma, life or death. Copyright © 2014 Elsevier Inc. All rights reserved.

Automated segmentation of geographic atrophy of the retinal epithelium via random forests in AREDS color fundus images☆

Science.gov (United States)

Feeny, Albert K.; Tadarati, Mongkol; Freund, David E.; Bressler, Neil M.; Burlina, Philippe

2015-01-01

Background Age-related macular degeneration (AMD), left untreated, is the leading cause of vision loss in people older than 55. Severe central vision loss occurs in the advanced stage of the disease, characterized by either the in growth of choroidal neovascularization (CNV), termed the “wet” form, or by geographic atrophy (GA) of the retinal pigment epithelium (RPE) involving the center of the macula, termed the “dry” form. Tracking the change in GA area over time is important since it allows for the characterization of the effectiveness of GA treatments. Tracking GA evolution can be achieved by physicians performing manual delineation of GA area on retinal fundus images. However, manual GA delineation is time-consuming and subject to inter-and intra-observer variability. Methods We have developed a fully automated GA segmentation algorithm in color fundus images that uses a supervised machine learning approach employing a random forest classifier. This algorithm is developed and tested using a dataset of images from the NIH-sponsored Age Related Eye Disease Study (AREDS). GA segmentation output was compared against a manual delineation by a retina specialist. Results Using 143 color fundus images from 55 different patient eyes, our algorithm achieved PPV of 0.82±0.19, and NPV of 0:95±0.07. Discussion This is the first study, to our knowledge, applying machine learning methods to GA segmentation on color fundus images and using AREDS imagery for testing. These preliminary results show promising evidence that machine learning methods may have utility in automated characterization of GA from color fundus images. PMID:26318113

Automated segmentation of geographic atrophy of the retinal epithelium via random forests in AREDS color fundus images.

Science.gov (United States)

Feeny, Albert K; Tadarati, Mongkol; Freund, David E; Bressler, Neil M; Burlina, Philippe

2015-10-01

Age-related macular degeneration (AMD), left untreated, is the leading cause of vision loss in people older than 55. Severe central vision loss occurs in the advanced stage of the disease, characterized by either the in growth of choroidal neovascularization (CNV), termed the "wet" form, or by geographic atrophy (GA) of the retinal pigment epithelium (RPE) involving the center of the macula, termed the "dry" form. Tracking the change in GA area over time is important since it allows for the characterization of the effectiveness of GA treatments. Tracking GA evolution can be achieved by physicians performing manual delineation of GA area on retinal fundus images. However, manual GA delineation is time-consuming and subject to inter-and intra-observer variability. We have developed a fully automated GA segmentation algorithm in color fundus images that uses a supervised machine learning approach employing a random forest classifier. This algorithm is developed and tested using a dataset of images from the NIH-sponsored Age Related Eye Disease Study (AREDS). GA segmentation output was compared against a manual delineation by a retina specialist. Using 143 color fundus images from 55 different patient eyes, our algorithm achieved PPV of 0.82±0.19, and NPV of 0:95±0.07. This is the first study, to our knowledge, applying machine learning methods to GA segmentation on color fundus images and using AREDS imagery for testing. These preliminary results show promising evidence that machine learning methods may have utility in automated characterization of GA from color fundus images. Copyright © 2015 Elsevier Ltd. All rights reserved.

A treatable cause of myelopathy and vision loss mimicking neuromyelitis optica spectrum disorder: late-onset biotinidase deficiency.

Science.gov (United States)

Yilmaz, Sanem; Serin, Mine; Canda, Ebru; Eraslan, Cenk; Tekin, Hande; Ucar, Sema Kalkan; Gokben, Sarenur; Tekgul, Hasan; Serdaroglu, Gul

2017-06-01

Biotinidase deficiency is characterized by severe neurological manifestations as hypotonia, lethargy, ataxia, hearing loss, seizures and developmental retardation in its classical form. Late-onset biotinidase deficiency presents distinctly from the classical form such as limb weakness and vision problems. A 14-year-old boy presented with progressive vision loss and upper limb weakness. The patient was initiated steroid therapy with a preliminary diagnosis of neuromyelitis optica spectrum disorder due to the craniospinal imaging findings demonstrating optic nerve, brainstem and longitudinally extensive spinal cord involvement. Although the patient exhibited partial clinical improvement after pulse steroid therapy, craniocervical imaging performed one month after the initiation of steroid therapy did not show any regression. The CSF IgG index was <0.8 (normal: <0.8), oligoclonal band and aquaporin-4 antibodies were negative. Metabolic investigations revealed a low biotinidase enzyme activity 8% (0.58 nmoL/min/mL; normal range: 4.4 to 12). Genetic testing showed c.98-104delinsTCC and p.V457 M mutations in biotinidase (BTD) gene. At the third month of biotin replacement therapy, control craniospinal MRI demonstrated a complete regression of the lesions. The muscle strength of the case returned to normal. His visual acuity was 7/10 in the left eye and 9/10 in the right. The late-onset form of the biotinidase deficiency should be kept in mind in all patients with myelopathy with or without vision loss, particularly in those with inadequate response to steroid therapy. The family screening is important to identify asymptomatic individuals and timely treatment.

Color-discrimination threshold determination using pseudoisochromatic test plates

Directory of Open Access Journals (Sweden)

Kaiva eJurasevska

2014-11-01

Full Text Available We produced a set of pseudoisochromatic plates for determining individual color-difference thresholds to assess test performance and test properties, and analyzed the results. We report a high test validity and classification ability for the deficiency type and severity level (comparable to that of the fourth edition of the Hardy–Rand–Rittler (HRR test. We discuss changes of the acceptable chromatic shifts from the protan and deutan confusion lines along the CIE xy diagram, and the high correlation of individual color-difference thresholds and the red–green discrimination index. Color vision was tested using an Oculus HMC anomaloscope, a Farnsworth D15, and an HRR test on 273 schoolchildren, and 57 other subjects with previously diagnosed red–green color-vision deficiency.

HYPERTENSIVE CHOROIDOPATHY AS AN UNCOMMON CAUSE S OF VISUAL LOSS IN PREGNANCY

Directory of Open Access Journals (Sweden)

Bijnya Birajita

2015-08-01

Full Text Available INTRODUCTION: HISTORY: A 30 year old lady in her 32 weeks gestation period was referred to our ophthalmology clinic with chief complaints of diminution of vision in both eyes for 4 months duration. Her medical history was suggestive of uncontrolled hypertension. On Ophthalmic evaluation she had best corrected visual acuity of 20/200 in both eyes with normal color vision. Her pupils were bilaterally equal in size and normally reacting to light. The intraocular pressure was within normal range and anterior segment evaluation was within normal limits. Dilated fundus evaluation revealed only arterio - venous crossing changes, mottled retina and resolving hard exudates in both eyes [Fig 1a, & 1 b]. The fundus picture could not explain the severity of vision loss in the patient which prompted us for further workup.

Frequency of color blindness in pre-employment screening in a tertiary health care center in Pakistan.

Science.gov (United States)

Chhipa, Shaukat Ali; Hashmi, Farzeen K; Ali, Shehreen; Kamal, Mustafa; Ahmad, Khabir

2017-01-01

To describe the frequency of color vision deficiency among Pakistani adults presenting for pre-employment health screening in a tertiary care hospital. The cross-sectional study was carried out at the Aga Khan University Hospital, Karachi, and the data was collected for color vision deficiency, age, gender, and job applied for from pre-employment examination during 2013-2014. IBM SPSS 20 was used for statistical analysis. Three thousand four hundred and thirty seven persons underwent pre-employment screening during 2013 and 2014; 1837 (53.44%) were males and 1600 (46.65%) females. The mean age was 29.01 (±6.53) years. A total of 0.9% (32/3437) persons had color vision deficiency with male being 1.4% and female 0.4%. Color vision deficiency was observed in 0.9% of candidates screened for pre-employment health check up in a tertiary care hospital. The color vision deficiency was predominantly present in male individuals.

Head-Mounted Display Technology for Low Vision Rehabilitation and Vision Enhancement

Science.gov (United States)

Ehrlich, Joshua R.; Ojeda, Lauro V.; Wicker, Donna; Day, Sherry; Howson, Ashley; Lakshminarayanan, Vasudevan; Moroi, Sayoko E.

2017-01-01

Purpose To describe the various types of head-mounted display technology, their optical and human factors considerations, and their potential for use in low vision rehabilitation and vision enhancement. Design Expert perspective. Methods An overview of head-mounted display technology by an interdisciplinary team of experts drawing on key literature in the field. Results Head-mounted display technologies can be classified based on their display type and optical design. See-through displays such as retinal projection devices have the greatest potential for use as low vision aids. Devices vary by their relationship to the user’s eyes, field of view, illumination, resolution, color, stereopsis, effect on head motion and user interface. These optical and human factors considerations are important when selecting head-mounted displays for specific applications and patient groups. Conclusions Head-mounted display technologies may offer advantages over conventional low vision aids. Future research should compare head-mounted displays to commonly prescribed low vision aids in order to compare their effectiveness in addressing the impairments and rehabilitation goals of diverse patient populations. PMID:28048975

A Vision Chip for Color Segmentation and Pattern Matching

Directory of Open Access Journals (Sweden)

Ralph Etienne-Cummings

2003-06-01

Full Text Available A 128(H × 64(V × RGB CMOS imager is integrated with region-of-interest selection, RGB-to-HSI transformation, HSI-based pixel segmentation, (36bins × 12bits-HSI histogramming, and sum-of-absolute-difference (SAD template matching. Thirty-two learned color templates are stored and compared to each image. The chip captures the R, G, and B images using in-pixel storage before passing the pixel content to a multiplying digital-to-analog converter (DAC for white balancing. The DAC can also be used to pipe in images for a PC. The color processing uses a biologically inspired color opponent representation and an analog lookup table to determine the Hue (H of each pixel. Saturation (S is computed using a loser-take-all circuit. Intensity (I is given by the sum of the color components. A histogram of the segments of the image, constructed by counting the number of pixels falling into 36 Hue intervals of 10 degrees, is stored on a chip and compared against the histograms of new segments using SAD comparisons. We demonstrate color-based image segmentation and object recognition with this chip. Running at 30 fps, it uses 1 mW. To our knowledge, this is the first chip that integrates imaging, color segmentation, and color-based object recognition at the focal plane.

[Acute monocular loss of vision : Differential diagnostic considerations apart from the internistic etiological clarification].

Science.gov (United States)

Rickmann, A; Macek, M A; Szurman, P; Boden, K

2017-08-03

We report the case of acute painless monocular loss of vision in a 53-year-old man. An interdisciplinary etiological evaluation remained without pathological findings with respect to arterial branch occlusion. A reevaluation of the patient history led to a possible association with the administration of phosphodiesterase type 5 inhibitor (PDE5 inhibitor). A critical review of the literature on PDE5 inhibitor administration with ocular participation was performed.

Improved reading performance using individualized compensation filters for observers with losses in central vision

Science.gov (United States)

Lawton, Teri B.

1989-01-01

A method to improve the reading performance of subjects with losses in central vision is proposed in which the amplitudes of the intermediate spatial frequencies are boosted relative to the lower spatial frequencies. In the method, words are filtered using an image enhancement function which is based on a subject's losses in visual function relative to a normal subject. It was found that 30-70 percent less magnification was necessary, and that reading rates were improved 2-3 times, using the method. The individualized compensation filters improved the clarity and visibility of words. The shape of the enhancement function was shown to be important in determining the optimum compensation filter for improving reading performance.

A Retrospective Study of Causes of Low Vision in Saud Arabia, A Case of Eye World Medical Complex in Riyadh.

Science.gov (United States)

Z Alotaibi, Abdullah

2015-10-20

Vision is the ability of seeing with a definite understanding of features, color and contrast, and to distinguish between objects visually. In the year 1999, the World Health Organization (WHO) and the International Agency for the Prevention of Blindness formulated a worldwide project for the eradication of preventable loss of sight with the subject of "Vision 2020: the Right to Sight". This global program aims to eradicate preventable loss of sight by the year 2020. This study was conducted to determine the main causes of low vision in Saudi Arabia and also to assess their visual improvement after using low vision aids (LVD).The study is a retrospective study and was conducted in low vision clinic at Eye World Medical Complex in Riyadh, Saudi Arabia. The file medical record of 280 patients attending low vision clinics from February 2008 to June 2010 was included. A data sheet was filled which include: age, gender, cause of low vision, unassisted visual acuity for long distances and short distances, low vision devices needed for long distances and short distances that provides best visual acuity. The result shows that the main cause of low vision was Optic atrophy (28.9%). Retinitis pigmentosa was the second cause of low vision, accounting for 73 patients (26%) followed by Diabetic retinopathy and Macular degeneration with 44 patients (15.7%) and 16 patients (5.7%) respectively. Inter family marriage could be one of the main causes of low vision. Public awareness should be embarked on for enlightenment on ocular diseases result in consanguineous marriage. Also, it is an important issue to start establishing low vision clinics in order to improve the situation.

Development and evaluation of vision rehabilitation devices.

Science.gov (United States)

Luo, Gang; Peli, Eli

2011-01-01

We have developed a range of vision rehabilitation devices and techniques for people with impaired vision due to either central vision loss or severely restricted peripheral visual field. We have conducted evaluation studies with patients to test the utilities of these techniques in an effort to document their advantages as well as their limitations. Here we describe our work on a visual field expander based on a head mounted display (HMD) for tunnel vision, a vision enhancement device for central vision loss, and a frequency domain JPEG/MPEG based image enhancement technique. All the evaluation studies included visual search paradigms that are suitable for conducting indoor controllable experiments.

Sudden Unilateral Vision Loss Arising from Calcified Amorphous Tumor of the Left Ventricle

Science.gov (United States)

Nazli, Yunus; Colak, Necmettin; Atar, Inci Asli; Alpay, Mehmet Fatih; Haltas, Hacer; Eryonucu, Beyhan; Cakir, Omer

2013-01-01

Calcified amorphous tumor of the heart is a very rare non-neoplastic intracavitary mass. The clinical presentation is similar to that of other cardiac masses. The precise cause and best approach to treatment remain unclear. We describe a case of cardiac calcified amorphous tumor presenting with refractory unilateral vision loss that was successfully treated by surgical excision. To our knowledge, this is only the 2nd reported case of retinal arterial embolism due to cardiac calcified amorphous tumor in the English-language literature. PMID:24082378

Multispectral Imaging of Meat Quality - Color and Texture

DEFF Research Database (Denmark)

Trinderup, Camilla Himmelstrup

transformations to the CIELAB color space, the common color space within food science. The results show that meat color assessment with a multispectral imaging is a great alternative to the traditional colorimeter, i.e. the vision system meets some of the limitations that the colorimeter possesses. To mention one...

Encyclopedia of color science and technology

CERN Document Server

2016-01-01

The Encyclopedia of Color Science and Technology provides an authoritative single source for understanding and applying the concepts of color to all fields of science and technology, including artistic and historical aspects of color. Many topics are discussed in this timely reference, including an introduction to the science of color, and entries on the physics, chemistry and perception of color. Color is described as it relates to optical phenomena of color and continues on through colorants and materials used to modulate color and also to human vision of color. The measurement of color is provided as is colorimetry, color spaces, color difference metrics, color appearance models, color order systems and cognitive color. Other topics discussed include industrial color, color imaging, capturing color, displaying color and printing color. Descriptions of color encodings, color management, processing color and applications relating to color synthesis for computer graphics are included in this work. The Encyclo...

INVIS : Integrated night vision surveillance and observation system

NARCIS (Netherlands)

Toet, A.; Hogervorst, M.A.; Dijk, J.; Son, R. van

2010-01-01

We present the design and first field trial results of the all-day all-weather INVIS Integrated Night Vision surveillance and observation System. The INVIS augments a dynamic three-band false-color nightvision image with synthetic 3D imagery in a real-time display. The night vision sensor suite

Consistency of color representation in smart phones.

Science.gov (United States)

Dain, Stephen J; Kwan, Benjamin; Wong, Leslie

2016-03-01

One of the barriers to the construction of consistent computer-based color vision tests has been the variety of monitors and computers. Consistency of color on a variety of screens has necessitated calibration of each setup individually. Color vision examination with a carefully controlled display has, as a consequence, been a laboratory rather than a clinical activity. Inevitably, smart phones have become a vehicle for color vision tests. They have the advantage that the processor and screen are associated and there are fewer models of smart phones than permutations of computers and monitors. Colorimetric consistency of display within a model may be a given. It may extend across models from the same manufacturer but is unlikely to extend between manufacturers especially where technologies vary. In this study, we measured the same set of colors in a JPEG file displayed on 11 samples of each of four models of smart phone (iPhone 4s, iPhone5, Samsung Galaxy S3, and Samsung Galaxy S4) using a Photo Research PR-730. The iPhones are white LED backlit LCD and the Samsung are OLEDs. The color gamut varies between models and comparison with sRGB space shows 61%, 85%, 117%, and 110%, respectively. The iPhones differ markedly from the Samsungs and from one another. This indicates that model-specific color lookup tables will be needed. Within each model, the primaries were quite consistent (despite the age of phone varying within each sample). The worst case in each model was the blue primary; the 95th percentile limits in the v' coordinate were ±0.008 for the iPhone 4 and ±0.004 for the other three models. The u'v' variation in white points was ±0.004 for the iPhone4 and ±0.002 for the others, although the spread of white points between models was u'v'±0.007. The differences are essentially the same for primaries at low luminance. The variation of colors intermediate between the primaries (e.g., red-purple, orange) mirror the variation in the primaries. The variation in

Color indirect effects on melatonin regulation

Science.gov (United States)

Mian, Tian; Liu, Timon C.; Li, Yan

2002-04-01

Color indirect effect (CIE) is referred to as the physiological and psychological effects of color resulting from color vision. In previous papers, we have studied CIE from the viewpoints of the integrated western and Chinese traditional medicine, put forward the color-autonomic- nervous-subsystem model (CAM), and provided its time-theory foundation. In this paper, we applied it to study light effects on melatonin regulation in humans, and suggested that it is CIE that mediates light effects on melatonin suppression.

Combining fine texture and coarse color features for color texture classification

Science.gov (United States)

Wang, Junmin; Fan, Yangyu; Li, Ning

2017-11-01

Color texture classification plays an important role in computer vision applications because texture and color are two fundamental visual features. To classify the color texture via extracting discriminative color texture features in real time, we present an approach of combining the fine texture and coarse color features for color texture classification. First, the input image is transformed from RGB to HSV color space to separate texture and color information. Second, the scale-selective completed local binary count (CLBC) algorithm is introduced to extract the fine texture feature from the V component in HSV color space. Third, both H and S components are quantized at an optimal coarse level. Furthermore, the joint histogram of H and S components is calculated, which is considered as the coarse color feature. Finally, the fine texture and coarse color features are combined as the final descriptor and the nearest subspace classifier is used for classification. Experimental results on CUReT, KTH-TIPS, and New-BarkTex databases demonstrate that the proposed method achieves state-of-the-art classification performance. Moreover, the proposed method is fast enough for real-time applications.

Eficiência dos testes cromáticos de comparação na discromatopsia hereditária: relato de casos Efficiency of color vision tests in hereditary dyschromatopsia: case report

Directory of Open Access Journals (Sweden)

Luciene Chaves Fernandes

2008-08-01

Full Text Available As autoras relatam dois casos de discromatopsia hereditária e discutem a eficiência dos testes cromáticos no diagnóstico de uma discromatopsia. Os pacientes foram reprovados em diferentes concursos públicos federais por apresentarem diagnóstico de discromatopsia hereditária pelo teste de Ishihara. Submeteram-se a exame oftalmológico, com resultados dentro da normalidade. Procuraram novo parecer para melhor caracterização da sua discromatopsia. Não havia sintomas relacionados à deficiência. Os testes Panel D15 simples, D28 de Roth mostraram-se normais e o D15 dessaturado confirmou deutanomalia no caso 1. No segundo caso os testes de comparação mostraram alterações sem significado cromático. O diagnóstico de uma discromatopsia é muito complexo. As autoras destacam a importância de realização de testes de visão cromática complementares ao teste de Ishihara para diagnóstico de uma discromatopsia.The authors describe two cases of hereditary dyschromatopsia and discuss the efficiency of the color vision tests. The patients were disapproved in different federal public examinations because Ishihara's test diagnosed hereditary dyschromatopsia. Ophthalmological evaluation was normal. No symptoms related to dyschromatopsia were presented. Panels D15 and Roth D 28 were normal. Desaturated D 15 showed deuteranomaly in case one. In the second case the comparative color vision tests showed nonspecific disorder. The diagnosis of dyschromatopsia is complex. The authors recommend comparative color vision tests to complement the Ishihara test for a better understanding of the color deficiency.

Barriers to accessing low vision services.

Science.gov (United States)

Pollard, Tamara L; Simpson, John A; Lamoureux, Ecosse L; Keeffe, Jill E

2003-07-01

To investigate barriers to accessing low vision services in Australia. Adults with a vision impairment (vision difficulties, duration of vision loss and satisfaction with vision and also examined issues of awareness of low vision services and referral to services. Focus groups were also conducted with vision impaired (Vision Australia Foundation. The discussions were recorded and transcribed. The questionnaire revealed that referral to low vision services was associated with a greater degree of vision loss (p = 0.002) and a greater self-perception of low vision (p = 0.005) but that referral was not associated with satisfaction (p = 0.144) or difficulties related to vision (p = 0.169). Participants with mild and moderate vision impairment each reported similar levels of difficulties with daily activities and satisfaction with their vision (p > 0.05). However, there was a significant difference in the level of difficulties experienced with daily activities between those with mild-moderate and severe vision impairment (p low vision services related to awareness of services among the general public and eye care professionals, understanding of low vision and the services available, acceptance of low vision, the referral process, and transport. In addition to the expected difficulties with lack of awareness of services by people with low vision, many people do not understand what the services provide and do not identify themselves as having low vision. Knowledge of these barriers, from the perspective of people with low vision, can now be used to guide the development and content of future health-promotion campaigns.

Stimulation of functional vision in children with perinatal brain damage.

Science.gov (United States)

Alimović, Sonja; Mejaski-Bosnjak, Vlatka

2011-01-01

Cerebral visual impairment (CVI) is one of the most common causes of bilateral visual loss, which frequently occurs due to perinatal brain injury. Vision in early life has great impact on acquisition of basic comprehensions which are fundamental for further development. Therefore, early detection of visual problems and early intervention is necessary. The aim of the present study is to determine specific visual functioning of children with perinatal brain damage and the influence of visual stimulation on development of functional vision at early age of life. We initially assessed 30 children with perinatal brain damage up to 3 years of age, who were reffered to our pediatric low vision cabinet in "Little house" from child neurologists, ophthalmologists Type and degree of visual impairment was determined according to functional vision assessment of each child. On the bases of those assessments different kind of visual stimulations were carried out with children who have been identified to have a certain visual impairment. Through visual stimulation program some of the children were stimulated with light stimulus, some with different materials under the ultraviolet (UV) light, and some with bright color and high contrast materials. Children were also involved in program of early stimulation of overall sensory motor development. Goals and methods of therapy were determined individually, based on observation of child's possibilities and need. After one year of program, reassessment was done. Results for visual functions and functional vision were compared to evaluate the improvement of the vision development. These results have shown that there was significant improvement in functional vision, especially in visual attention and visual communication.

Machine Vision System for Color Sorting Wood Edge-Glued Panel Parts

Science.gov (United States)

Qiang Lu; S. Srikanteswara; W. King; T. Drayer; Richard Conners; D. Earl Kline; Philip A. Araman

1997-01-01

This paper describes an automatic color sorting system for hardwood edge-glued panel parts. The color sorting system simultaneously examines both faces of a panel part and then determines which face has the "better" color given specified color uniformity and priority defined by management. The real-time color sorting system software and hardware are briefly...

Number of discernible colors for color-deficient observers estimated from the MacAdam limits.

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Perales, Esther; Martínez-Verdú, Francisco Miguel; Linhares, João Manuel Maciel; Nascimento, Sérgio Miguel Cardoso

2010-10-01

We estimated the number of colors perceived by color normal and color-deficient observers when looking at the theoretic limits of object-color stimuli. These limits, the optimal color stimuli, were computed for a color normal observer and CIE standard illuminant D65, and the resultant colors were expressed in the CIELAB and DIN99d color spaces. The corresponding color volumes for abnormal color vision were computed using models simulating for normal trichromatic observers the appearance for dichromats and anomalous trichomats. The number of colors perceived in each case was then computed from the color volumes enclosed by the optimal colors also known as MacAdam limits. It was estimated that dichromats perceive less than 1% of the colors perceived by normal trichromats and that anomalous trichromats perceive 50%-60% for anomalies in the medium-wavelength-sensitive and 60%-70% for anomalies in the long-wavelength-sensitive cones. Complementary estimates obtained similarly for the spectral locus of monochromatic stimuli suggest less impairment for color-deficient observers, a fact that is explained by the two-dimensional nature of the locus.

Impact of Congenital Color Vision Defect on Color‑related Tasks ...

African Journals Online (AJOL)

Table 1]. In activities of daily .... Watching sports because of color of team jersey. 1628 (99.6). 2 (0.1). 2 (0.1). 1 (0.1). 2 (0.1). 1635 (100) .... difficulty with selecting colors of clothes, identifying colors in sports, workplace, hobbies, and road signals.

Cross-orientation masking in human color vision: application of a two-stage model to assess dichoptic and monocular sources of suppression.

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Kim, Yeon Jin; Gheiratmand, Mina; Mullen, Kathy T

2013-05-28

Cross-orientation masking (XOM) occurs when the detection of a test grating is masked by a superimposed grating at an orthogonal orientation, and is thought to reveal the suppressive effects mediating contrast normalization. Medina and Mullen (2009) reported that XOM was greater for chromatic than achromatic stimuli at equivalent spatial and temporal frequencies. Here we address whether the greater suppression found in binocular color vision originates from a monocular or interocular site, or both. We measure monocular and dichoptic masking functions for red-green color contrast and achromatic contrast at three different spatial frequencies (0.375, 0.75, and 1.5 cpd, 2 Hz). We fit these functions with a modified two-stage masking model (Meese & Baker, 2009) to extract the monocular and interocular weights of suppression. We find that the weight of monocular suppression is significantly higher for color than achromatic contrast, whereas dichoptic suppression is similar for both. These effects are invariant across spatial frequency. We then apply the model to the binocular masking data using the measured values of the monocular and interocular sources of suppression and show that these are sufficient to account for color binocular masking. We conclude that the greater strength of chromatic XOM has a monocular origin that transfers through to the binocular site.

Vision in water.

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Atchison, David A; Valentine, Emma L; Gibson, Georgina; Thomas, Hannah R; Oh, Sera; Pyo, Young Ah; Lacherez, Philippe; Mathur, Ankit

2013-09-06

The purpose of this study is to determine visual performance in water, including the influence of pupil size. The water environment was simulated by placing goggles filled with saline in front of the eyes with apertures placed at the front of the goggles. Correction factors were determined for the different magnification under this condition in order to estimate vision in water. Experiments were conducted on letter visual acuity (seven participants), grating resolution (eight participants), and grating contrast sensitivity (one participant). For letter acuity, mean loss of vision in water, compared to corrected vision in air, varied between 1.1 log min of arc resolution (logMAR) for a 1 mm aperture to 2.2 logMAR for a 7 mm aperture. The vision in min of arc was described well by a linear relationship with pupil size. For grating acuity, mean loss varied between 1.1 logMAR for a 2 mm aperture to 1.2 logMAR for a 6 mm aperture. Contrast sensitivity for a 2 mm aperture deteriorated as spatial frequency increased with a 2 log unit loss by 3 c/°. Superimposed on this deterioration were depressions (notches) in sensitivity with the first three notches occurring at 0.45, 0.8, and 1.3 c/° with estimates for water of 0.39, 0.70, and 1.13 c/°. In conclusion, vision in water is poor. It becomes worse as pupil size increases, but the effects are much more marked for letter targets than for grating targets.

A robust embedded vision system feasible white balance algorithm

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Wang, Yuan; Yu, Feihong

2018-01-01

White balance is a very important part of the color image processing pipeline. In order to meet the need of efficiency and accuracy in embedded machine vision processing system, an efficient and robust white balance algorithm combining several classical ones is proposed. The proposed algorithm mainly has three parts. Firstly, in order to guarantee higher efficiency, an initial parameter calculated from the statistics of R, G and B components from raw data is used to initialize the following iterative method. After that, the bilinear interpolation algorithm is utilized to implement demosaicing procedure. Finally, an adaptive step adjustable scheme is introduced to ensure the controllability and robustness of the algorithm. In order to verify the proposed algorithm's performance on embedded vision system, a smart camera based on IMX6 DualLite, IMX291 and XC6130 is designed. Extensive experiments on a large amount of images under different color temperatures and exposure conditions illustrate that the proposed white balance algorithm avoids color deviation problem effectively, achieves a good balance between efficiency and quality, and is suitable for embedded machine vision processing system.

A Sensitive Dynamic and Active Pixel Vision Sensor for Color or Neural Imaging Applications.

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Moeys, Diederik Paul; Corradi, Federico; Li, Chenghan; Bamford, Simeon A; Longinotti, Luca; Voigt, Fabian F; Berry, Stewart; Taverni, Gemma; Helmchen, Fritjof; Delbruck, Tobi

2018-02-01

Applications requiring detection of small visual contrast require high sensitivity. Event cameras can provide higher dynamic range (DR) and reduce data rate and latency, but most existing event cameras have limited sensitivity. This paper presents the results of a 180-nm Towerjazz CIS process vision sensor called SDAVIS192. It outputs temporal contrast dynamic vision sensor (DVS) events and conventional active pixel sensor frames. The SDAVIS192 improves on previous DAVIS sensors with higher sensitivity for temporal contrast. The temporal contrast thresholds can be set down to 1% for negative changes in logarithmic intensity (OFF events) and down to 3.5% for positive changes (ON events). The achievement is possible through the adoption of an in-pixel preamplification stage. This preamplifier reduces the effective intrascene DR of the sensor (70 dB for OFF and 50 dB for ON), but an automated operating region control allows up to at least 110-dB DR for OFF events. A second contribution of this paper is the development of characterization methodology for measuring DVS event detection thresholds by incorporating a measure of signal-to-noise ratio (SNR). At average SNR of 30 dB, the DVS temporal contrast threshold fixed pattern noise is measured to be 0.3%-0.8% temporal contrast. Results comparing monochrome and RGBW color filter array DVS events are presented. The higher sensitivity of SDAVIS192 make this sensor potentially useful for calcium imaging, as shown in a recording from cultured neurons expressing calcium sensitive green fluorescent protein GCaMP6f.

DLP™-based dichoptic vision test system

Science.gov (United States)

Woods, Russell L.; Apfelbaum, Henry L.; Peli, Eli

2010-01-01

It can be useful to present a different image to each of the two eyes while they cooperatively view the world. Such dichoptic presentation can occur in investigations of stereoscopic and binocular vision (e.g., strabismus, amblyopia) and vision rehabilitation in clinical and research settings. Various techniques have been used to construct dichoptic displays. The most common and most flexible modern technique uses liquid-crystal (LC) shutters. When used in combination with cathode ray tube (CRT) displays, there is often leakage of light from the image intended for one eye into the view of the other eye. Such interocular crosstalk is 14% even in our state of the art CRT-based dichoptic system. While such crosstalk may have minimal impact on stereo movie or video game experiences, it can defeat clinical and research investigations. We use micromirror digital light processing (DLP™) technology to create a novel dichoptic visual display system with substantially lower interocular crosstalk (0.3% remaining crosstalk comes from the LC shutters). The DLP system normally uses a color wheel to display color images. Our approach is to disable the color wheel, synchronize the display directly to the computer's sync signal, allocate each of the three (former) color presentations to one or both eyes, and open and close the LC shutters in synchrony with those color events.

Protein loss in human hair from combination straightening and coloring treatments.

Science.gov (United States)

França-Stefoni, Simone Aparecida; Dario, Michelli Ferrera; Sá-Dias, Tânia Cristina; Bedin, Valcinir; de Almeida, Adriano José; Baby, André Rolim; Velasco, Maria Valéria R

2015-09-01

Hair chemical treatments, such as dyeing and straightening products, are known to cause damage that can be assessed by protein loss. The aim of this study was to evaluate the hair protein loss caused by combined chemical treatments (dye and relaxer) using the validated bicinchoninic acid (BCA) method. Three kinds of straighteners, based on ammonium thioglycolate, guanidine hydroxide and sodium hydroxide, were evaluated and the least harmful combination indicated. Caucasian virgin dark brown hair tresses were treated with developed natural brown color oxidative hair dyeing and/or straightening commercial products based on ammonium thioglycolate, sodium hydroxide, or guanidine hydroxide. Protein loss quantification was assessed by the validated BCA method which has several advantages for quantifying protein loss in chemically treated hair. When both treatments (straightening and dyeing) were combined, a higher negative effect was observed, particularly for dyed hair treated with sodium hydroxide. In this case, a 356% increase in protein loss relative to virgin hair was observed and 208% in relation to only dyed hair. The combination of dying and relaxers based on ammonium thioglycolate or guanidine hydroxide caused a small increase in protein loss, suggesting that these straightening products could be the best alternatives for individuals wishing to combine both treatments. These results indicated that when application of both types of products is desired, ammonium thioglycolate or guanidine hydroxide should be chosen for the straightening process. © 2015 Wiley Periodicals, Inc.

Development and clinical application of a color pediatric visual acuity chart

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Shu-Guo Yin

2014-12-01

Full Text Available AIM: To introduce a new color pediatric visual acuity chart and its clinical application.METHODS:The color pediatric visual acuity chart was designed based on principle of visual angle. The optotype on the color chart had graphics. The progression rate of optotype size between 2 lines was 10(101/2 and 1.2589. A regular geometric progression of optotype sizes and distribution was employed to arrange 8 lines with 11 optotype on the color chart. The testing distance was 3m. The visual acuity score could be recorded as logarithm of the minimum angle of resolution notation or decimal notation. The reliability of naked distant measurements with this new chart was tested in one eye of 100 children(4 ～6 years oldtaking the Chinese national standard logarithm visual acuity chart standard. RESULTS: The color pediatric visual acuity chart and logarithmic chart controls, visual acuity test results that in the two groups had no significant difference(t=1.2671, P>0.05. Two sets of vision data existed positive correlation(r=0.924, PCONCLUSION:Children are easier to accept used new color pediatric visual acuity chart to inspect vision. New chart is reliability and apply to children's vision screening.

How to Keep Your Sight for Life

Science.gov (United States)

... vision), eye coordination, depth perception, focusing ability, and color vision. Common impairments to vision include near-sightedness, ... NEI). Vision loss ranks ahead of loss of memory, speech, arm or leg, and hearing. After all, ...

Soft Computing Techniques in Vision Science

CERN Document Server

Yang, Yeon-Mo

2012-01-01

This Special Edited Volume is a unique approach towards Computational solution for the upcoming field of study called Vision Science. From a scientific firmament Optics, Ophthalmology, and Optical Science has surpassed an Odyssey of optimizing configurations of Optical systems, Surveillance Cameras and other Nano optical devices with the metaphor of Nano Science and Technology. Still these systems are falling short of its computational aspect to achieve the pinnacle of human vision system. In this edited volume much attention has been given to address the coupling issues Computational Science and Vision Studies.  It is a comprehensive collection of research works addressing various related areas of Vision Science like Visual Perception and Visual system, Cognitive Psychology, Neuroscience, Psychophysics and Ophthalmology, linguistic relativity, color vision etc. This issue carries some latest developments in the form of research articles and presentations. The volume is rich of contents with technical tools ...

A meta-analysis of the effects of shockwave and high pressure processing on color and cook loss of fresh meat.

Science.gov (United States)

Ha, Minh; Dunshea, Frank R; Warner, Robyn D

2017-10-01

Meta-analysis is a statistical approach for investigating experimental differences across studies. Meta-analyses were performed to examine the effects of hydrodynamic processing (shockwave; n=12 papers) and high pressure processing (HPP; n=8 papers) on the color and cook loss of fresh meat. Shockwave did not affect color (L*, a*), whereas cook loss was increased by 0.6% relative to untreated meat. HPP resulted in an increase in lightness (L*) and a decrease in redness (a*), with the effect being greater at higher pressures (>300MPa vs pressure (high pressure (>300MPa) the cook loss was increased (-1.5% vs 3.0% respectively). The increased cook loss with shockwave and high pressure (>300MPa) processing needs to be balanced against benefits in texture if this technology is applied to meat. The reduced cook loss of meat treated at moderate pressures (<300MPa) is an advantage which would likely improve sensory traits. Copyright © 2017 Elsevier Ltd. All rights reserved.

Broiler skin and meat color changes during storage.

Science.gov (United States)

Petracci, M; Fletcher, D L

2002-10-01

The importance of poultry skin and meat color (both absolute and variations in color) in the market place have been well established. It has also been reported that these colors change over time. With the development of computer-assisted vision grading systems, the changes in skin and meat color during and after processing have become important, based on calibrations and assessment values based on color. Four independent experiments were conducted to determine the pattern of color change in broiler skin and meat during processing and storage. Skin color change was measured on subscald (57 C) and semiscald (50 C) breast skin surfaces and on breast and leg meat, on the carcass and following deboning and packaging. A reflectance colorimeter was used to determine lightness (L*), redness (a*), and yellowness (b*) at 20-min intervals for the first 3 h, at 30-min intervals between 3 and 8 h, hourly between 8 and 12 h, and daily up to 8 d postmortem. Results clearly show that color values for both skin and meat changed dramatically for the first 6 h postmortem, after which the changes were less pronounced. The skin from semiscalded birds showed less change than the skin from subscalded birds. These results indicate that on-line vision systems need to take into account the dramatic changes in skin and meat color during the first 6 h postmortem, after which the color changes may be less important.

Vision Rehabilitation is Part of AMD Care

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August Colenbrander

2018-01-01

Full Text Available AMD does not just affect the retina. It severely affects people’s lives. Paying attention to this aspect will only become more important as the population ages and more otherwise healthy individuals become affected. This paper will discuss the need for teamwork to overcome the difference between medical care, which addresses the causes of AMD, and rehabilitative care, which addresses the consequences. Different aspects and different degrees of vision loss ask for different interventions. Loss of detailed vision can be addressed by a wide variety of magnification devices. The means to address this aspect are well recognized. Surround vision is largely processed pre-attentively. Its loss cannot be remediated by devices, but must be addressed through patient education to bring previously subconscious reactions to conscious awareness. Loss of contrast vision is an aspect that is not sufficiently studied. It is important for early detection, and for the safety of the patient. When the eye condition cannot be modified, environmental modifications provide the most effective remediation.

Low Vision Devices and Training

Directory of Open Access Journals (Sweden)

Imran Azam Butt

2004-01-01

Full Text Available Vision is the ability to see with a clear perception of detail, colour and contrast, and to distinguish objects visually. Like any other sense, vision tends to deteriorate or diminish naturally with age. In most cases, reduction in visual capability can be corrected with glasses, medicine or surgery. However, if the visual changes occur because of an incurable eye disease, condition or injury, vision loss can be permanent. Many people around the world with permanent visual impairment have some residual vision which can be used with the help of low vision services, materials and devices. This paper describes different options for the enhancement of residual vision including optical and non-optical devices and providing training for the low vision client.

Derivation of Color Confusion Lines for Pseudo-Dichromat Observers from Color Discrimination Thresholds

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Kahiro Matsudaira

2011-05-01

Full Text Available The objective is to develop a method of defining color confusion lines in the display RGB color space through color discrimination tasks. In the experiment, reference and test square patches were presented side by side on a CRT display. The subject's task is to set the test color where the color difference from the reference is just noticeable to him/her. In a single trial, the test color was only adjustable along one of 26 directions around the reference. Thus 26 colors with just noticeable difference (JND were obtained and made up a tube-like or an ellipsoidal shape around each reference. With color-anomalous subjects, the major axes of these shapes should be parallel to color confusion lines that have a common orientation vector corresponding to one of the cone excitation axes L, M, or S. In our method, the orientation vector was determined by minimizing the sum of the squares of the distances from JND colors to each confusion line. To assess the performance the method, the orientation vectors obtained by pseudo-dichromats (color normal observers with a dichromat simulator were compared to those theoretically calculated from the color vision model used in the simulator.

Vision restoration after brain and retina damage: the "residual vision activation theory".

Science.gov (United States)

Sabel, Bernhard A; Henrich-Noack, Petra; Fedorov, Anton; Gall, Carolin

2011-01-01

Vision loss after retinal or cerebral visual injury (CVI) was long considered to be irreversible. However, there is considerable potential for vision restoration and recovery even in adulthood. Here, we propose the "residual vision activation theory" of how visual functions can be reactivated and restored. CVI is usually not complete, but some structures are typically spared by the damage. They include (i) areas of partial damage at the visual field border, (ii) "islands" of surviving tissue inside the blind field, (iii) extrastriate pathways unaffected by the damage, and (iv) downstream, higher-level neuronal networks. However, residual structures have a triple handicap to be fully functional: (i) fewer neurons, (ii) lack of sufficient attentional resources because of the dominant intact hemisphere caused by excitation/inhibition dysbalance, and (iii) disturbance in their temporal processing. Because of this resulting activation loss, residual structures are unable to contribute much to everyday vision, and their "non-use" further impairs synaptic strength. However, residual structures can be reactivated by engaging them in repetitive stimulation by different means: (i) visual experience, (ii) visual training, or (iii) noninvasive electrical brain current stimulation. These methods lead to strengthening of synaptic transmission and synchronization of partially damaged structures (within-systems plasticity) and downstream neuronal networks (network plasticity). Just as in normal perceptual learning, synaptic plasticity can improve vision and lead to vision restoration. This can be induced at any time after the lesion, at all ages and in all types of visual field impairments after retinal or brain damage (stroke, neurotrauma, glaucoma, amblyopia, age-related macular degeneration). If and to what extent vision restoration can be achieved is a function of the amount of residual tissue and its activation state. However, sustained improvements require repetitive

Fuzzy-based simulation of real color blindness.

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Lee, Jinmi; dos Santos, Wellington P

2010-01-01

About 8% of men are affected by color blindness. That population is at a disadvantage since they cannot perceive a substantial amount of the visual information. This work presents two computational tools developed to assist color blind people. The first one tests color blindness and assess its severity. The second tool is based on Fuzzy Logic, and implements a method proposed to simulate real red and green color blindness in order to generate synthetic cases of color vision disturbance in a statistically significant amount. Our purpose is to develop correction tools and obtain a deeper understanding of the accessibility problems faced by people with chromatic visual impairment.

Low Vision Care: The Need to Maximise Visual Potential

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Ramachandra Pararajasegaram

2004-01-01

Full Text Available People with low vision have residual vision with some light perception, but their vision loss does not lend itself to improvement by standard spectacles or medical or surgical treatment. Such persons have the potential for enhanced functional vision if they receive appropriate low vision care services.

A multi-stage color model revisited: implications for a gene therapy cure for red-green colorblindness.

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Mancuso, Katherine; Mauck, Matthew C; Kuchenbecker, James A; Neitz, Maureen; Neitz, Jay

2010-01-01

In 1993, DeValois and DeValois proposed a 'multi-stage color model' to explain how the cortex is ultimately able to deconfound the responses of neurons receiving input from three cone types in order to produce separate red-green and blue-yellow systems, as well as segregate luminance percepts (black-white) from color. This model extended the biological implementation of Hurvich and Jameson's Opponent-Process Theory of color vision, a two-stage model encompassing the three cone types combined in a later opponent organization, which has been the accepted dogma in color vision. DeValois' model attempts to satisfy the long-remaining question of how the visual system separates luminance information from color, but what are the cellular mechanisms that establish the complicated neural wiring and higher-order operations required by the Multi-stage Model? During the last decade and a half, results from molecular biology have shed new light on the evolution of primate color vision, thus constraining the possibilities for the visual circuits. The evolutionary constraints allow for an extension of DeValois' model that is more explicit about the biology of color vision circuitry, and it predicts that human red-green colorblindness can be cured using a retinal gene therapy approach to add the missing photopigment, without any additional changes to the post-synaptic circuitry.

Preferred skin color enhancement for photographic color reproduction

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Zeng, Huanzhao; Luo, Ronnier

2011-01-01

Skin tones are the most important colors among the memory color category. Reproducing skin colors pleasingly is an important factor in photographic color reproduction. Moving skin colors toward their preferred skin color center improves the color preference of skin color reproduction. Several methods to morph skin colors to a smaller preferred skin color region has been reported in the past. In this paper, a new approach is proposed to further improve the result of skin color enhancement. An ellipsoid skin color model is applied to compute skin color probabilities for skin color detection and to determine a weight for skin color adjustment. Preferred skin color centers determined through psychophysical experiments were applied for color adjustment. Preferred skin color centers for dark, medium, and light skin colors are applied to adjust skin colors differently. Skin colors are morphed toward their preferred color centers. A special processing is applied to avoid contrast loss in highlight. A 3-D interpolation method is applied to fix a potential contouring problem and to improve color processing efficiency. An psychophysical experiment validates that the method of preferred skin color enhancement effectively identifies skin colors, improves the skin color preference, and does not objectionably affect preferred skin colors in original images.

Participation of the elderly after vision loss

NARCIS (Netherlands)

Alma, M.A.; Mei, van der S.F.; Melis-Dankers, B.J.M.; Tilburg, van T.G.; Groothoff, J.W.; Suurmeijer, T.P.B.M.

2011-01-01

Purpose. To assess the degree of participation of the visually impaired elderly and to make a comparison with population-based reference data. Method. This cross-sectional study included visually impaired elderly persons (≥55 years; n=173) who were referred to a low-vision rehabilitation centre.

Color discrimination impairment in workers exposed to mercury vapor.

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Urban, Pavel; Gobba, Fabriziomaria; Nerudová, Jana; Lukás, Edgar; Cábelková, Zdena; Cikrt, Miroslav

2003-08-01

To study color discrimination impairment in workers exposed to elemental mercury (Hg) vapor. Twenty-four male workers from a chloralkali plant exposed to Hg vapor, aged 42+/-9.8 years, duration of exposure 14.7+/-9.7 years, were examined. The 8h TWA air-borne Hg concentration in workplace was 59 microg/m(3); mean Hg urinary excretion (HgU) was 20.5+/-19.3 microg/g creatinine; mean Hg urinary excretion after the administration of a chelating agent, sodium 2,3-dimercapto-1-propane-sulfonate (DMPS), was 751.9+/-648 microg/48h. Twenty-four age- and gender-matched control subjects were compared. Visual acuity, alcohol intake, smoking habits, and history of diseases or drugs potentially influencing color vision were registered. The Lanthony 15-Hue desaturated test (L-D15-d) was used to assess color vision. The results were expressed quantitatively as Bowman's Color Confusion Index (CCI), and qualitatively according to Verriest's classification of acquired dyschromatopsias. The CCI was significantly higher in the exposed group than in the control (mean CCI 1.15 versus 1.04; P=0.04). The proportion of subjects with errorless performance on the Lanthony test was significantly lower in the Hg exposed group compared to referents (52% versus 73%; P=0.035). The exposed group showed higher frequency of type III dyschromatopsias (blue-yellow confusion axis) in comparison with the control group (12.5% versus 8.3%), however, the difference did not reach statistical significance. Multiple regression did not show any significant relationship between the CCI, and age, alcohol consumption, or measures of exposure. In agreement with previous studies by Cavalleri et al. [Toxicol. Lett. 77 (1995) 351; Environ. Res. Sec. A 77 (1998) 173], the results of this study support the hypothesis that exposure to mercury vapor can induce sub-clinical color vision impairment. This effect was observed at an exposure level below the current biological limit for occupational exposure to mercury. This

Cost effectiveness of strategies to combat vision and hearing loss in sub-Saharan Africa and South East Asia: mathematical modelling study.

NARCIS (Netherlands)

Baltussen, R.M.; Smith, A.

2012-01-01

OBJECTIVE: To determine the relative costs, effects, and cost effectiveness of selected interventions to control cataract, trachoma, refractive error, hearing loss, meningitis and chronic otitis media. DESIGN: Cost effectiveness analysis of or combined strategies for controlling vision and hearing

Human V4 Activity Patterns Predict Behavioral Performance in Imagery of Object Color.

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Bannert, Michael M; Bartels, Andreas

2018-04-11

Color is special among basic visual features in that it can form a defining part of objects that are engrained in our memory. Whereas most neuroimaging research on human color vision has focused on responses related to external stimulation, the present study investigated how sensory-driven color vision is linked to subjective color perception induced by object imagery. We recorded fMRI activity in male and female volunteers during viewing of abstract color stimuli that were red, green, or yellow in half of the runs. In the other half we asked them to produce mental images of colored, meaningful objects (such as tomato, grapes, banana) corresponding to the same three color categories. Although physically presented color could be decoded from all retinotopically mapped visual areas, only hV4 allowed predicting colors of imagined objects when classifiers were trained on responses to physical colors. Importantly, only neural signal in hV4 was predictive of behavioral performance in the color judgment task on a trial-by-trial basis. The commonality between neural representations of sensory-driven and imagined object color and the behavioral link to neural representations in hV4 identifies area hV4 as a perceptual hub linking externally triggered color vision with color in self-generated object imagery. SIGNIFICANCE STATEMENT Humans experience color not only when visually exploring the outside world, but also in the absence of visual input, for example when remembering, dreaming, and during imagery. It is not known where neural codes for sensory-driven and internally generated hue converge. In the current study we evoked matching subjective color percepts, one driven by physically presented color stimuli, the other by internally generated color imagery. This allowed us to identify area hV4 as the only site where neural codes of corresponding subjective color perception converged regardless of its origin. Color codes in hV4 also predicted behavioral performance in an

Spatial contrast sensitivity vision loss in children with cortical visual impairment.

Science.gov (United States)

Good, William V; Hou, Chuan; Norcia, Anthony M

2012-11-19

Although cortical visual impairment (CVI) is the leading cause of bilateral vision impairment in children in Western countries, little is known about the effects of CVI on visual function. The aim of this study was to compare visual evoked potential measures of contrast sensitivity and grating acuity in children with CVI with those of age-matched typically developing controls. The swept parameter visual evoked potential (sVEP) was used to measure contrast sensitivity and grating acuity in 34 children with CVI at 5 months to 5 years of age and in 16 age-matched control children. Contrast thresholds and spatial frequency thresholds (grating acuities) were derived by extrapolating the tuning functions to zero amplitude. These thresholds and maximal suprathreshold response amplitudes were compared between groups. Among 34 children with CVI, 30 had measurable but reduced contrast sensitivity with a median threshold of 10.8% (range 5.0%-30.0% Michelson), and 32 had measurable but reduced grating acuity with median threshold 0.49 logMAR (9.8 c/deg, range 5-14 c/deg). These thresholds were significantly reduced, compared with age-matched control children. In addition, response amplitudes over the entire sweep range for both measures were significantly diminished in children with CVI compared with those of control children. Our results indicate that spatial contrast sensitivity and response amplitudes are strongly affected by CVI. The substantial degree of loss in contrast sensitivity suggests that contrast is a sensitive measure for evaluating vision deficits in patients with CVI.

Quality Parameters of Six Cultivars of Blueberry Using Computer Vision

Directory of Open Access Journals (Sweden)

Silvia Matiacevich

2013-01-01

Full Text Available Background. Blueberries are considered an important source of health benefits. This work studied six blueberry cultivars: “Duke,” “Brigitta”, “Elliott”, “Centurion”, “Star,” and “Jewel”, measuring quality parameters such as °Brix, pH, moisture content using standard techniques and shape, color, and fungal presence obtained by computer vision. The storage conditions were time (0–21 days, temperature (4 and 15°C, and relative humidity (75 and 90%. Results. Significant differences (P<0.05 were detected between fresh cultivars in pH, °Brix, shape, and color. However, the main parameters which changed depending on storage conditions, increasing at higher temperature, were color (from blue to red and fungal presence (from 0 to 15%, both detected using computer vision, which is important to determine a shelf life of 14 days for all cultivars. Similar behavior during storage was obtained for all cultivars. Conclusion. Computer vision proved to be a reliable and simple method to objectively determine blueberry decay during storage that can be used as an alternative approach to currently used subjective measurements.

Using color and grayscale images to teach histology to color-deficient medical students.

Science.gov (United States)

Rubin, Lindsay R; Lackey, Wendy L; Kennedy, Frances A; Stephenson, Robert B

2009-01-01

Examination of histologic and histopathologic microscopic sections relies upon differential colors provided by staining techniques, such as hematoxylin and eosin, to delineate normal tissue components and to identify pathologic alterations in these components. Given the prevalence of color deficiency (commonly called "color blindness") in the general population, it is likely that this reliance upon color differentiation poses a significant obstacle for several medical students beginning a course of study that includes examination of histologic slides. In the past, first-year medical students at Michigan State University who identified themselves as color deficient were encouraged to use color transparency overlays or tinted contact lenses to filter out problematic colors. Recently, however, we have offered such students a computer monitor adjusted to grayscale for in-lab work, as well as grayscale copies of color photomicrographs for examination purposes. Grayscale images emphasize the texture of tissues and the contrasts between tissues as the students learn histologic architecture. Using this approach, color-deficient students have quickly learned to compensate for their deficiency by focusing on cell and tissue structure rather than on color variation. Based upon our experience with color-deficient students, we believe that grayscale photomicrographs may also prove instructional for students with normal (trichromatic) color vision, by encouraging them to consider structural characteristics of cells and tissues that may otherwise be overshadowed by stain colors.

Role of vision and mechanoreception in bed bug, Cimex lectularius L. behavior.

Directory of Open Access Journals (Sweden)

Narinderpal Singh

Full Text Available The role of olfactory cues such as carbon dioxide, pheromones, and kairomones in bed bug, Cimex lectularius L. behavior has been demonstrated. However, the role of vision and mechanoreception in bed bug behavior is poorly understood. We investigated bed bug vision by determining their responses to different colors, vertical objects, and their ability to detect colors and vertical objects under low and complete dark conditions. Results show black and red paper harborages are preferred compared to yellow, green, blue, and white harborages. A bed bug trapping device with a black or red exterior surface was significantly more attractive to bed bugs than that with a white exterior surface. Bed bugs exhibited strong orientation behavior toward vertical objects. The height (15 vs. 30 cm tall and color (brown vs. black of the vertical object had no significant effect on orientation behavior of bed bugs. Bed bugs could differentiate color and detect vertical objects at very low background light conditions, but not in complete darkness. Bed bug preference to different substrate textures (mechanoreception was also explored. Bed bugs preferred dyed tape compared to painted tape, textured painted plastic, and felt. These results revealed that substrate color, presence of vertical objects, and substrate texture affect host-seeking and harborage-searching behavior of bed bugs. Bed bugs may use a combination of vision, mechanoreception, and chemoreception to locate hosts and seek harborages.

Color constancy in Japanese animation

Science.gov (United States)

Ichihara, Yasuyo G.

2006-01-01

In this study, we measure the colors used in a Japanese Animations. The result can be seen on CIE-xy color spaces. It clearly shows that the color system is not a natural appearance system but an imagined and artistic appearance system. Color constancy of human vision can tell the difference in skin and hair colors between under moonlight and day light. Human brain generates a match to the memorized color of an object from daylight viewing conditions to the color of the object in different viewing conditions. For example, Japanese people always perceive the color of the Rising Sun in the Japanese flag as red even in a different viewing condition such as under moonlight. Color images captured by a camera cannot present those human perceptions. However, Japanese colorists in Animation succeeded in painting the effects of color constancy not only under moonlight but also added the memory matching colors. They aim to create a greater impact on viewer's perceptions by using the effect of the memory matching colors. In this paper, we propose the Imagined Japanese Animation Color System. This system in art is currently a subject of research in Japan. Its importance is that it could also provide an explanation on how human brain perceives the same color under different viewing conditions.

The fabrication of a multi-spectral lens array and its application in assisting color blindness

Science.gov (United States)

Di, Si; Jin, Jian; Tang, Guanrong; Chen, Xianshuai; Du, Ruxu

2016-01-01

This article presents a compact multi-spectral lens array and describes its application in assisting color-blindness. The lens array consists of 9 microlens, and each microlens is coated with a different color filter. Thus, it can capture different light bands, including red, orange, yellow, green, cyan, blue, violet, near-infrared, and the entire visible band. First, the fabrication process is described in detail. Second, an imaging system is setup and a color blindness testing card is selected as the sample. By the system, the vision results of normal people and color blindness can be captured simultaneously. Based on the imaging results, it is possible to be used for helping color-blindness to recover normal vision.

Color Space and Its Divisions: Color Order from Antiquity to the Present

Science.gov (United States)

Kuehni, Rolf G.

2003-03-01

It has been postulated that humans can differentiate between millions of gradations in color. Not surprisingly, no completely adequate, detailed catalog of colors has yet been devised, however the quest to understand, record, and depict color is as old as the quest to understand the fundamentals of the physical world and the nature of human consciousness. Rolf Kuehni's Color Space and Its Divisions: Color Order from Antiquity to the Present represents an ambitious and unprecedented history of man's inquiry into color order, focusing on the practical applications of the most contemporary developments in the field. Kuehni devotes much of his study to geometric, three-dimensional arrangements of color experiences, a type of system developed only in the mid-nineteenth century. Color spaces are of particular interest for color quality-control purposes in the manufacturing and graphics industries. The author analyzes three major color order systems in detail: Munsell, OSA-UCS, and NCS. He presents historical and current information on color space developments in color vision, psychology, psychophysics, and color technology. Chapter topics include: A historical account of color order systems Fundamentals of psychophysics and the relationship between stimuli and experience Results of perceptual scaling of colors according to attributes History of the development of mathematical color space and difference formulas Analysis of the agreements and discrepancies in psychophysical data describing color differences An experimental plan for the reliable, replicated perceptual data necessary to make progress in the field Experts in academia and industry, neuroscientists, designers, art historians, and anyone interested in the nature of color will find Color Space and Its Divisions to be the authoritative reference in its field.

Neurologic state transitions in the eye and brain: kinetics of loss and recovery of vision and consciousness.

Science.gov (United States)

Whinnery, Typ; Forster, Estrella M

2015-01-01

Visual alterations, peripheral light loss (PLL) and blackout (BO), are components of acceleration (+Gz) induced loss of consciousness (LOC) and recovery of consciousness (ROC). The kinetics of loss of vision (LOV) and recovery of vision (ROV) were determined utilizing ocular pressure induced retinal ischemia and compared to the kinetics of LOC and ROC resulting from +Gz-induced cephalic nervous system (CPNS) ischemia. The time from self-induced retinal ischemia in completely healthy subjects (N = 104) to the onset of PLL and complete BO was measured. The time from release of ocular pressure, with return of normal retinal circulation, to the time for complete recovery of visual fields was also measured. The kinetics of pressure induced LOV and ROV was compared with previously developed kinetics of +Gz-induced LOC and ROC focusing on the rapid onset, vertical arm, of the +Gz-induced LOC and ROC curves. The time from onset of increased ocular pressure, immediately inducing retinal ischemia, to PLL was 5.04 s with the time to BO being 8.73 s. Complete recovery of the visual field from BO following release of ocular pressure, immediately abolishing retinal ischemia, was 2.74 s. These results confirm experimental findings that visual loss is frequently not experienced prior to LOC during exposure to rapid onset, high levels of +Gz-stress above tolerance. Offset of pressure induced retinal ischemia to ROV was 2.74 s, while the time from offset of +Gz-induced CPNS ischemia to ROC was 5.29 s. Recovery of retinal function would be predicted to be complete before consciousness is regained following +Gz-induced LOC. Ischemia onset time normalization in neurologic tissues permits comparison between different stress-induced times to altered function. The +Gz-time tolerance curves for LOV and LOC provide comparison and integration of neurologic state transition kinetics in the retina and CPNS.

Gender inequality in vision loss and eye diseases: Evidence from the Sultanate of Oman

Directory of Open Access Journals (Sweden)

Khandekar Rajiv

2009-01-01

Full Text Available Purpose : The data from surveys of vision loss and monitoring of services were used to assess changes in gender inequality in Oman. Study Design : Retrospective review of data collection instruments. Materials and Method : The data sets of 12 years between 1996 and 2007 were abstracted to assess the gender equality for vision loss, eye disease prevalence, and service use. They included two surveys (1996 and 2005, Health Information from eye units (1998 and 2007, and eye screening in schools. Results : In 1996, the prevalence of bilateral blindness in ≥ 40 years of age was higher in females [Odd′s Ratio (OR = 0.36 (95% Confidence Interval (CI 0.24 - 0.53]. Gender differences in the prevalence of cataract [OR = 0.82 (95% CI 0.63 - 1.03] were not significant while trachomatous trichaisis (TT was less in males [OR = 0.33 (95% CI 0.22-0.48]. In 2005, gender differences in the prevalence of bilateral blindness [OR = 0.97 (95% CI 0.71 - 1.34] and TT [OR = 0.66 (95% CI 0.42- 1.04] were not statistically significant.But males were associated with higher prevalence of cataract [OR = 1.26 (95% CI 1.00 - 1.59]. Surgery rates for cataract, glaucoma and TT were not different by gender. More male compared to female patients with diabetic retinopathy were treated. Myopia was significantly higher in girls. Compliance of spectacle wear was higher in girls. Conclusions : Gender inequality for eye care seems to have reduced in the last 10 years in Oman. However, apart from TT and glaucoma patients the difference in service utilization by gender was not statistically significant.

Scanner-based macroscopic color variation estimation

Science.gov (United States)

Kuo, Chunghui; Lai, Di; Zeise, Eric

2006-01-01

Flatbed scanners have been adopted successfully in the measurement of microscopic image artifacts, such as granularity and mottle, in print samples because of their capability of providing full color, high resolution images. Accurate macroscopic color measurement relies on the use of colorimeters or spectrophotometers to provide a surrogate for human vision. The very different color response characteristics of flatbed scanners from any standard colorimetric response limits the utility of a flatbed scanner as a macroscopic color measuring device. This metamerism constraint can be significantly relaxed if our objective is mainly to quantify the color variations within a printed page or between pages where a small bias in measured colors can be tolerated as long as the color distributions relative to the individual mean values is similar. Two scenarios when converting color from the device RGB color space to a standardized color space such as CIELab are studied in this paper, blind and semi-blind color transformation, depending on the availability of the black channel information. We will show that both approaches offer satisfactory results in quantifying macroscopic color variation across pages while the semi-blind color transformation further provides fairly accurate color prediction capability.

Color features for quality control in ceramic tile industry

Science.gov (United States)

Kukkonen, Saku; Kaelviaeinen, Heikki; Parkkinen, Jussi P.

2001-02-01

We study visual quality control in the ceramics industry. In the manufacturing, it is important that in each set of tiles, every single tile looks similar. Currently, the estimation is usually done by human vision. Our goal is to design a machine vision system that can estimate the sufficient similarity, or same appearance, to the human eye. Our main approach is to use accurate spectral representation of color, and compare spectral features to the RGB color features. A laboratory system for color measurements is built. Experimentations with five classes of brown tiles are presented and discussed. In addition to the k-nearest neighbor (k-NN) classifier, a neural network called the self-organizing map (SOM) is used to provide understanding of the spectral features. Every single spectrum in each tile of a training set is used as input to a 2D SOM. The SOM is analyzed to understand how spectra are clustered. As a result, tiles are classified using a trained 2D SOM. It is also of interest to know whether the order of spectral colors can be determined. In our approach, all spectra are clustered in a 1D SOM, and each pixel spectrum) is presented by pseudocolors according to the trained nodes. Finally, the results are compared to experiments with human vision.

The influence of active vision on the exoskeleton of intelligent agents

Science.gov (United States)

Smith, Patrice; Terry, Theodore B.

2016-04-01

Chameleonization occurs when a self-learning autonomous mobile system's (SLAMR) active vision scans the surface of which it is perched causing the exoskeleton to changes colors exhibiting a chameleon effect. Intelligent agents having the ability to adapt to their environment and exhibit key survivability characteristics of its environments would largely be due in part to the use of active vision. Active vision would allow the intelligent agent to scan its environment and adapt as needed in order to avoid detection. The SLAMR system would have an exoskeleton, which would change, based on the surface it was perched on; this is known as the "chameleon effect." Not in the common sense of the term, but from the techno-bio inspired meaning as addressed in our previous paper. Active vision, utilizing stereoscopic color sensing functionality would enable the intelligent agent to scan an object within its close proximity, determine the color scheme, and match it; allowing the agent to blend with its environment. Through the use of its' optical capabilities, the SLAMR system would be able to further determine its position, taking into account spatial and temporal correlation and spatial frequency content of neighboring structures further ensuring successful background blending. The complex visual tasks of identifying objects, using edge detection, image filtering, and feature extraction are essential for an intelligent agent to gain additional knowledge about its environmental surroundings.

Drying and radial shrinkage characteristics and changes in color ...

African Journals Online (AJOL)

Drying and radial shrinkage characteristics and changes in color and shape of carrots tissues during air drying were studied. Slices dimensions were obtained by computer vision and the color was quantified by chroma, hue, whitening index and total carotenoids contents. The drying time became shorter of 1 h when ...

Mobile Atmospheric Sensing using Vision Approach

International Nuclear Information System (INIS)

Huang, Yuchun; Cui, Weihong; Rui, Yi

2014-01-01

Air quality monitoring, especially the atmospheric phenomenon of thick haze, has been an acute problem in most countries and a hot topic in the atmospheric sensing. Recently thick haze occurs more frequently in most cities of China due to the rapid growth of traffic, farming, wildfires, and industrial development. It forms a low-hanging shroud that impairs visibility and becomes a respiratory health threat. Traditionally the dust, smoke, and other particles in relatively dry sky are reported at fixed meteorological stations. The coverage of these sampling stations is limited and cannot accommodate with the emergent incidence of thick haze from industrial pollution. In addition, the visual effect of thick haze is not yet investigated in the current practice. Thick haze appears colorful veil (e.g., yellowish, brownish-grey, etc) in video log images and results in a loss of contrast in the subject due to the light scattering through haze particles. This paper proposes an intuitive and mobile atmospheric sensing using vision approach. Based on the video log images collected by a mobile sensing vehicle, a Haze Veil Index (HVI) is proposed to identify the type and severity level of thick haze from the color and texture perspective. HVI characterizes the overall veil effect of haze spatially. HVI first identifies the haze color from the color deviation histogram of the white-balanced hazy image. The white-balancing is conducted with the most haze-opaque pixels in the dark channel and seed growing strategy. Then pixel-wise haze severity level of atmospheric veil is inferred by approximating the upper veil limit with the dark color of each pixel in a hazy image. The proposed method is tested on a diverse set of actual hazy video log images under varying atmospheric conditions and backgrounds in Wuhan City, China. Experimental results show the proposed HVI is effective for visually atmospheric sensing. The proposed method is promising for haze monitoring and prediction in

On the purposes of color for living beings: toward a theory of color organization.

Science.gov (United States)

Pinna, Baingio; Reeves, Adam

2015-01-01

Phylogenetic and paleontological evidence indicates that in the animal kingdom the ability to perceive colors evolved independently several times over the course of millennia. This implies a high evolutionary neural investment and suggests that color vision provides some fundamental biological benefits. What are these benefits? Why are some animals so colorful? What are the adaptive and perceptual meanings of polychromatism? We suggest that in addition to the discrimination of light and surface chromaticity, sensitivity to color contributes to the whole, the parts and the fragments of perceptual organization. New versions of neon color spreading and the watercolor illusion indicate that the visual purpose of color in humans is threefold: to inter-relate each chromatic component of an object, thus favoring the emergence of the whole; to support a part-whole organization in which components reciprocally enhance each other by amodal completion; and, paradoxically, to reveal fragments and hide the whole-that is, there is a chromatic parceling-out process of separation, division, and fragmentation of the whole. The evolution of these contributions of color to organization needs to be established, but traces of it can be found in Harlequin camouflage by animals and in the coloration of flowers.

Functional Vision Observation. Technical Assistance Paper.

Science.gov (United States)

Florida State Dept. of Education, Tallahassee. Bureau of Education for Exceptional Students.

Technical assistance is provided concerning documentation of functional vision loss for Florida students with visual impairments. The functional vision observation should obtain enough information for determination of special service eligibility. The observation is designed to supplement information on the medical eye examination, and is conducted…

The color of money

DEFF Research Database (Denmark)

Ásgeirsson, Árni Gunnar; Kristjánsson, Árni; Einarsdóttir, Kristin Vala

2014-01-01

of attention are affected by reward, and whether the effect involves general enhancement or is specific to discrete components of attention. Observers viewed brief displays of differentially colored letters and reported their identity. Each color signified a consistent monetary value and we measured......, by including conditions with color-contingent negative values. This gave an opportunity to compare high-gain with high-loss conditions. We found clear effects of value on selectivity when comparing high- and low-value conditions. When comparing equally valuable high-loss and high-gain conditions there were...

Fabric Weave Pattern and Yarn Color Recognition and Classification Using a Deep ELM Network

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Babar Khan

2017-10-01

Full Text Available Usually, a fabric weave pattern is recognized using methods which identify the warp floats and weft floats. Although these methods perform well for uniform or repetitive weave patterns, in the case of complex weave patterns, these methods become computationally complex and the classification error rates are comparatively higher. Furthermore, the fault-tolerance (invariance and stability (selectivity of the existing methods are still to be enhanced. We present a novel biologically-inspired method to invariantly recognize the fabric weave pattern (fabric texture and yarn color from the color image input. We proposed a model in which the fabric weave pattern descriptor is based on the HMAX model for computer vision inspired by the hierarchy in the visual cortex, the color descriptor is based on the opponent color channel inspired by the classical opponent color theory of human vision, and the classification stage is composed of a multi-layer (deep extreme learning machine. Since the weave pattern descriptor, yarn color descriptor, and the classification stage are all biologically inspired, we propose a method which is completely biologically plausible. The classification performance of the proposed algorithm indicates that the biologically-inspired computer-aided-vision models might provide accurate, fast, reliable and cost-effective solution to industrial automation.

Plaque Brachytherapy for Uveal Melanoma: A Vision Prognostication Model

International Nuclear Information System (INIS)

Khan, Niloufer; Khan, Mohammad K.; Bena, James; Macklis, Roger; Singh, Arun D.

2012-01-01

Purpose: To generate a vision prognostication model after plaque brachytherapy for uveal melanoma. Methods and Materials: All patients with primary single ciliary body or choroidal melanoma treated with iodine-125 or ruthenium-106 plaque brachytherapy between January 1, 2005, and June 30, 2010, were included. The primary endpoint was loss of visual acuity. Only patients with initial visual acuity better than or equal to 20/50 were used to evaluate visual acuity worse than 20/50 at the end of the study, and only patients with initial visual acuity better than or equal to 20/200 were used to evaluate visual acuity worse than 20/200 at the end of the study. Factors analyzed were sex, age, cataracts, diabetes, tumor size (basal dimension and apical height), tumor location, and radiation dose to the tumor apex, fovea, and optic disc. Univariate and multivariable Cox proportional hazards were used to determine the influence of baseline patient factors on vision loss. Kaplan-Meier curves (log rank analysis) were used to estimate freedom from vision loss. Results: Of 189 patients, 92% (174) were alive as of February 1, 2011. At presentation, visual acuity was better than or equal to 20/50 and better than or equal to 20/200 in 108 and 173 patients, respectively. Of these patients, 44.4% (48) had post-treatment visual acuity of worse than 20/50 and 25.4% (44) had post-treatment visual acuity worse than 20/200. By multivariable analysis, increased age (hazard ratio [HR] of 1.01 [1.00-1.03], P=.05), increase in tumor height (HR of 1.35 [1.22-1.48], P<.001), and a greater total dose to the fovea (HR of 1.01 [1.00-1.01], P<.001) were predictive of vision loss. This information was used to develop a nomogram predictive of vision loss. Conclusions: By providing a means to predict vision loss at 3 years after treatment, our vision prognostication model can be an important tool for patient selection and treatment counseling.

Plaque Brachytherapy for Uveal Melanoma: A Vision Prognostication Model

Energy Technology Data Exchange (ETDEWEB)

Khan, Niloufer [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio (United States); Khan, Mohammad K. [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, Georgia (United States); Bena, James [Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio (United States); Macklis, Roger [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio (United States); Singh, Arun D., E-mail: singha@ccf.org [Department of Ophthalmic Oncology, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (United States)

2012-11-01

Purpose: To generate a vision prognostication model after plaque brachytherapy for uveal melanoma. Methods and Materials: All patients with primary single ciliary body or choroidal melanoma treated with iodine-125 or ruthenium-106 plaque brachytherapy between January 1, 2005, and June 30, 2010, were included. The primary endpoint was loss of visual acuity. Only patients with initial visual acuity better than or equal to 20/50 were used to evaluate visual acuity worse than 20/50 at the end of the study, and only patients with initial visual acuity better than or equal to 20/200 were used to evaluate visual acuity worse than 20/200 at the end of the study. Factors analyzed were sex, age, cataracts, diabetes, tumor size (basal dimension and apical height), tumor location, and radiation dose to the tumor apex, fovea, and optic disc. Univariate and multivariable Cox proportional hazards were used to determine the influence of baseline patient factors on vision loss. Kaplan-Meier curves (log rank analysis) were used to estimate freedom from vision loss. Results: Of 189 patients, 92% (174) were alive as of February 1, 2011. At presentation, visual acuity was better than or equal to 20/50 and better than or equal to 20/200 in 108 and 173 patients, respectively. Of these patients, 44.4% (48) had post-treatment visual acuity of worse than 20/50 and 25.4% (44) had post-treatment visual acuity worse than 20/200. By multivariable analysis, increased age (hazard ratio [HR] of 1.01 [1.00-1.03], P=.05), increase in tumor height (HR of 1.35 [1.22-1.48], P<.001), and a greater total dose to the fovea (HR of 1.01 [1.00-1.01], P<.001) were predictive of vision loss. This information was used to develop a nomogram predictive of vision loss. Conclusions: By providing a means to predict vision loss at 3 years after treatment, our vision prognostication model can be an important tool for patient selection and treatment counseling.

A Novel Mechanism for Color Vision: Pupil Shape and Chromatic Aberration Can Provide Spectral Discrimination for Color Blind Organisms.

OpenAIRE

Stubbs, Christopher; Stubbs, Alexander

2015-01-01

We present a mechanism by which organisms with only a single photoreceptor, that have a monochromatic view of the world, can achieve color discrimination. The combination of an off axis pupil and the principle of chromatic aberration (where light of different colors focus at different distances behind a lens) can combine to provide color-blind animals with a way to distinguish colors. As a specific example we constructed a computer model of the visual system of cephalopods, (octopus, squid, a...

A Novel Mechanism for Color Vision: Pupil Shape and Chromatic Aberration Can Provide Spectral Discrimination for Color Blind Organisms.

OpenAIRE

Stubbs, Alexander L; Stubbs, Christopher William

2016-01-01

We present a mechanism by which organisms with only a single photoreceptor, that have a monochromatic view of the world, can achieve color discrimination. The combination of an off axis pupil and the principle of chromatic aberration (where light of different colors focus at different distances behind a lens) can combine to provide color-blind animals with a way to distinguish colors. As a specific example we constructed a computer model of the visual system of cephalopods, (octopus, squid, a...

Biological origins of color categorization.

Science.gov (United States)

Skelton, Alice E; Catchpole, Gemma; Abbott, Joshua T; Bosten, Jenny M; Franklin, Anna

2017-05-23

The biological basis of the commonality in color lexicons across languages has been hotly debated for decades. Prior evidence that infants categorize color could provide support for the hypothesis that color categorization systems are not purely constructed by communication and culture. Here, we investigate the relationship between infants' categorization of color and the commonality across color lexicons, and the potential biological origin of infant color categories. We systematically mapped infants' categorical recognition memory for hue onto a stimulus array used previously to document the color lexicons of 110 nonindustrialized languages. Following familiarization to a given hue, infants' response to a novel hue indicated that their recognition memory parses the hue continuum into red, yellow, green, blue, and purple categories. Infants' categorical distinctions aligned with common distinctions in color lexicons and are organized around hues that are commonly central to lexical categories across languages. The boundaries between infants' categorical distinctions also aligned, relative to the adaptation point, with the cardinal axes that describe the early stages of color representation in retinogeniculate pathways, indicating that infant color categorization may be partly organized by biological mechanisms of color vision. The findings suggest that color categorization in language and thought is partially biologically constrained and have implications for broader debate on how biology, culture, and communication interact in human cognition.

Color consilience: color through the lens of art practice, history, philosophy, and neuroscience.

Science.gov (United States)

Conway, Bevil R

2012-03-01

Paintings can be interpreted as the product of the complex neural machinery that translates physical light signals into behavior, experience, and emotion. The brain mechanisms responsible for vision and perception have been sculpted during evolution and further modified by cultural exposure and development. By closely examining artists' paintings and practices, we can discover hints to how the brain works, and achieve insight into the discoveries and inventions of artists and their impact on culture. Here, I focus on an integral aspect of color, color contrast, which poses a challenge for artists: a mark situated on an otherwise blank canvas will appear a different color in the context of the finished painting. How do artists account for this change in color during the production of a painting? In the broader context of neural and philosophical considerations of color, I discuss the practices of three modern masters, Henri Matisse, Paul Cézanne, and Claude Monet, and suggest that the strategies they developed not only capitalized on the neural mechanisms of color, but also influenced the trajectory of western art history. © 2012 New York Academy of Sciences.

Cropping management using color and color infrared aerial photographs

Science.gov (United States)

Morgan, K. M.; Morris-Jones, D. R.; Lee, G. B.; Kiefer, R. W.

1979-01-01

The Universal Soil Loss Equation (USLE) is a widely accepted tool for erosion prediction and conservation planning. Solving this equation yields the long-term average annual soil loss that can be expected from rill and inter-rill erosion. In this study, manual interpretation of color and color infrared 70 mm photography at the scale of 1:60,000 is used to determine the cropping management factor in the USLE. Accurate information was collected about plowing practices and crop residue cover (unharvested vegetation) for the winter season on agricultural land in Pheasant Branch Creek watershed in Dane County, Wisconsin.

Ability of Bottle Cap Color to Facilitate Accurate Patient-Physician Communication Regarding Medication Identity in Patients with Glaucoma.

Science.gov (United States)

Dave, Pujan; Villarreal, Guadalupe; Friedman, David S; Kahook, Malik Y; Ramulu, Pradeep Y

2015-12-01

To determine the accuracy of patient-physician communication regarding topical ophthalmic medication use based on bottle cap color, particularly among individuals who may have acquired color vision deficiency from glaucoma. Cross-sectional, clinical study. Patients aged ≥18 years with primary open-angle, primary angle-closure, pseudoexfoliation, or pigment dispersion glaucoma, bilateral visual acuity of ≥20/400, and no concurrent conditions that may affect color vision. A total of 100 patients provided color descriptions of 11 distinct medication bottle caps. Color descriptors were then presented to 3 physicians. Physicians matched each color descriptor to the medication they thought the descriptor was describing. Frequency of patient-physician agreement, occurring when all 3 physicians accurately matched the color descriptor to the correct medication. Multivariate regression models evaluated whether patient-physician agreement decreased with degree of better-eye visual field (VF) damage, color descriptor heterogeneity, or color vision deficiency, as determined by the Hardy-Rand-Rittler (HRR) score and Lanthony D15 color confusion index (D15 CCI). Subjects had a mean age of 69 (±11) years, with VF mean deviation of -4.7 (±6.0) and -10.9 (±8.4) decibels (dB) in the better- and worse-seeing eyes, respectively. Patients produced 102 unique color descriptors to describe the colors of the 11 bottle caps. Among individual patients, the mean number of medications demonstrating agreement was 6.1/11 (55.5%). Agreement was less than 15% for 4 medications (prednisolone acetate [generic], betaxolol HCl [Betoptic; Alcon Laboratories Inc., Fort Worth, TX], brinzolamide/brimonidine [Simbrinza; Alcon Laboratories Inc.], and latanoprost [Xalatan; Pfizer, Inc., New York, NY]). Lower HRR scores and higher D15 CCI (both indicating worse color vision) were associated with greater VF damage (P communication using bottle cap color alone may be common and could lead to confusion

Monitoring system of multiple fire fighting based on computer vision

Science.gov (United States)

Li, Jinlong; Wang, Li; Gao, Xiaorong; Wang, Zeyong; Zhao, Quanke

2010-10-01

With the high demand of fire control in spacious buildings, computer vision is playing a more and more important role. This paper presents a new monitoring system of multiple fire fighting based on computer vision and color detection. This system can adjust to the fire position and then extinguish the fire by itself. In this paper, the system structure, working principle, fire orientation, hydrant's angle adjusting and system calibration are described in detail; also the design of relevant hardware and software is introduced. At the same time, the principle and process of color detection and image processing are given as well. The system runs well in the test, and it has high reliability, low cost, and easy nodeexpanding, which has a bright prospect of application and popularization.

Myoglobin chemistry and meat color.

Science.gov (United States)

Suman, Surendranath P; Joseph, Poulson

2013-01-01

Consumers rely heavily on fresh meat color as an indicator of wholesomeness at the point of sale, whereas cooked color is exploited as an indicator of doneness at the point of consumption. Deviations from the bright cherry-red color of fresh meat lead to product rejection and revenue loss. Myoglobin is the sarcoplasmic heme protein primarily responsible for the meat color, and the chemistry of myoglobin is species specific. The mechanistic interactions between myoglobin and multiple extrinsic and intrinsic factors govern the color of raw as well as cooked meats. The objective of this review is to provide an overview of the current research in meat color and how the findings are applied in the meat industry. Characterizing the fundamental basis of myoglobin's interactions with biomolecules in postmortem skeletal muscles is necessary to interpret the chemistry of meat color phenomena and to engineer innovative processing strategies to minimize meat discoloration-induced revenue loss to the agricultural economy.

Color Image Quality Assessment Based on CIEDE2000

Directory of Open Access Journals (Sweden)

Yang Yang

2012-01-01

Full Text Available Combining the color difference formula of CIEDE2000 and the printing industry standard for visual verification, we present an objective color image quality assessment method correlated with subjective vision perception. An objective score conformed to subjective perception (OSCSP Q was proposed to directly reflect the subjective visual perception. In addition, we present a general method to calibrate correction factors of color difference formula under real experimental conditions. Our experiment results show that the present DE2000-based metric can be consistent with human visual system in general application environment.

Family Functioning and Low Vision: A Systematic Review

Science.gov (United States)

Bambara, Jennifer K.; Wadley, Virginia; Owsley, Cynthia; Martin, Roy C.; Porter, Chebon; Dreer, Laura E.

2009-01-01

This review highlights the literature on the function and adjustment process of family members of persons with adult-onset vision loss. The majority of the literature has focused on the unique role that the family plays in providing both instrumental and emotional support to adults with low vision. In contrast, the impact of low vision on the…

Effects of blue light-filtering intraocular lenses on the macula, contrast sensitivity, and color vision after a long-term follow-up.

Science.gov (United States)

Kara-Junior, Newton; Espindola, Rodrigo F; Gomes, Beatriz A F; Ventura, Bruna; Smadja, David; Santhiago, Marcony R

2011-12-01

To evaluate the possible side effects and potential protection 5 years after implantation of an intraocular lens (IOL) with a blue-light filter (yellow tinted). Ophthalmology Department, University of São Paulo, São Paulo, Brazil. Prospective randomized clinical study. Patients with bilateral visually significant cataract randomly received an ultraviolet (UV) and blue light-filtering IOL (Acrysof Natural SN60AT) in 1 eye and an acrylic UV light-filtering only IOL (Acrysof SA60AT) in the fellow eye. The primary outcome measures were contrast sensitivity, color vision, and macular findings 5 years after surgery. The study enrolled 60 eyes of 30 patients. There were no significant clinical or optical coherence tomography findings in terms of age-related macular degeneration in any eye. There were no statistically significant differences in central macular thickness between the 2 IOL groups (P=.712). There were also no significant between-group differences under photopic or scotopic conditions at any spatial frequency studied. No statistically significant differences in the color discrimination test were found between the 2 IOL groups (P=.674). After 5 years, there were no significant differences in color perception, scotopic contrast sensitivity, or photopic contrast sensitivity between the blue light-filtering (yellow-tinted) IOL and the IOL with a UV-light filter only (untinted). The potential advantage of the tinted IOL in providing protection to macular cells remains unclear. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Advances in low-level color image processing

CERN Document Server

Smolka, Bogdan

2014-01-01

Color perception plays an important role in object recognition and scene understanding both for humans and intelligent vision systems. Recent advances in digital color imaging and computer hardware technology have led to an explosion in the use of color images in a variety of applications including medical imaging, content-based image retrieval, biometrics, watermarking, digital inpainting, remote sensing, visual quality inspection, among many others. As a result, automated processing and analysis of color images has become an active area of research, to which the large number of publications of the past two decades bears witness. The multivariate nature of color image data presents new challenges for researchers and practitioners as the numerous methods developed for single channel images are often not directly applicable to multichannel  ones. The goal of this volume is to summarize the state-of-the-art in the early stages of the color image processing pipeline.

Development of a vision-based pH reading system

Science.gov (United States)

Hur, Min Goo; Kong, Young Bae; Lee, Eun Je; Park, Jeong Hoon; Yang, Seung Dae; Moon, Ha Jung; Lee, Dong Hoon

2015-10-01

pH paper is generally used for pH interpretation in the QC (quality control) process of radiopharmaceuticals. pH paper is easy to handle and useful for small samples such as radio-isotopes and radioisotope (RI)-labeled compounds for positron emission tomography (PET). However, pHpaper-based detecting methods may have some errors due limitations of eye sight and inaccurate readings. In this paper, we report a new device for pH reading and related software. The proposed pH reading system is developed with a vision algorithm based on the RGB library. The pH reading system is divided into two parts. First is the reading device that consists of a light source, a CCD camera and a data acquisition (DAQ) board. To improve the accuracy of the sensitivity, we utilize the three primary colors of the LED (light emission diode) in the reading device. The use of three colors is better than the use of a single color for a white LED because of wavelength. The other is a graph user interface (GUI) program for a vision interface and report generation. The GUI program inserts the color codes of the pH paper into the database; then, the CCD camera captures the pH paper and compares its color with the RGB database image in the reading mode. The software captures and reports information on the samples, such as pH results, capture images, and library images, and saves them as excel files.

Increased steroidogenesis promotes early-onset and severe vision loss in females with OPA1 dominant optic atrophy

DEFF Research Database (Denmark)

Sarzi, Emmanuelle; Seveno, Marie; Angebault, Claire

2016-01-01

levels of steroid precursor pregnenolone in females, causing an early-onset vision loss, abolished by ovariectomy. In addition, steroid production in retina is also increased which, in conjunction with high circulating levels, impairs estrogen receptor expression and mitochondrial respiratory complex IV...... tested the hypothesis of deregulated steroid production in retina due to a disease-causing OPA1 mutation and its contribution to the visual phenotypic variations. Using the mouse model carrying the human recurrent OPA1 mutation, we disclosed that Opa1 haploinsufficiency leads to very high circulating...

Evaluation of Next-Generation Vision Testers for Aeromedical Certification of Aviation Personnel

Science.gov (United States)

2009-07-01

measure distant, intermediate, and near acuity. The slides are essentially abbreviated versions of the Early Treatment for Diabetic Retinopathy Study...over, requiring intermediate vision testing and 12 were color deficient. Analysis was designed to detect statistically significant differences between...Vertical Phoria (Right & Left Hyperphoria) Test scores from each of the vision testers were collated and analyzed. Analysis was designed to detect

Severe structural and functional visual system damage leads to profound loss of vision-related quality of life in patients with neuromyelitis optica spectrum disorders.

Science.gov (United States)

Schmidt, Felix; Zimmermann, Hanna; Mikolajczak, Janine; Oertel, Frederike C; Pache, Florence; Weinhold, Maria; Schinzel, Johann; Bellmann-Strobl, Judith; Ruprecht, Klemens; Paul, Friedemann; Brandt, Alexander U

2017-01-01

Neuromyelitis optica spectrum disorders (NMOSD) are characterized by devastating optic neuritis attacks causing more structural damage and visual impairment than in multiple sclerosis (MS). The objective of this study was to compare vision-related quality of life in NMOSD and MS patients and correlate it to structural retinal damage and visual function. Thirty-one NMOSD and 31 matched MS patients were included. Vision-related quality of life was assessed with the 39-item National Eye Institute Visual Function Questionnaire (NEI-VFQ). All patients underwent retinal optical coherence tomography and visual acuity and contrast sensitivity measurements. Vision-related quality of life was reduced in NMOSD compared to MS patients. This difference was driven by a higher incidence of bilateral and more severe optic neuritis in the NMOSD group. Retinal thinning and visual impairment were significantly greater in the NMOSD cohort. Lower vision-related quality of life was associated with more retinal damage and reduced visual function as assessed by visual acuity and contrast sensitivity. NMOSD-related bilateral ON-attacks cause severe structural damage and visual impairment that lead to severe loss of vision-related quality of life. The NEI-VFQ is a helpful tool to monitor vision-related quality of life in NMOSD patients. Copyright © 2016 Elsevier B.V. All rights reserved.

Scene recognition and colorization for vehicle infrared images

Science.gov (United States)

Hou, Junjie; Sun, Shaoyuan; Shen, Zhenyi; Huang, Zhen; Zhao, Haitao

2016-10-01

In order to make better use of infrared technology for driving assistance system, a scene recognition and colorization method is proposed in this paper. Various objects in a queried infrared image are detected and labelled with proper categories by a combination of SIFT-Flow and MRF model. The queried image is then colorized by assigning corresponding colors according to the categories of the objects appeared. The results show that the strategy here emphasizes important information of the IR images for human vision and could be used to broaden the application of IR images for vehicle driving.

Prior Knowledge about Objects Determines Neural Color Representation in Human Visual Cortex.

Science.gov (United States)

Vandenbroucke, A R E; Fahrenfort, J J; Meuwese, J D I; Scholte, H S; Lamme, V A F

2016-04-01

To create subjective experience, our brain must translate physical stimulus input by incorporating prior knowledge and expectations. For example, we perceive color and not wavelength information, and this in part depends on our past experience with colored objects ( Hansen et al. 2006; Mitterer and de Ruiter 2008). Here, we investigated the influence of object knowledge on the neural substrates underlying subjective color vision. In a functional magnetic resonance imaging experiment, human subjects viewed a color that lay midway between red and green (ambiguous with respect to its distance from red and green) presented on either typical red (e.g., tomato), typical green (e.g., clover), or semantically meaningless (nonsense) objects. Using decoding techniques, we could predict whether subjects viewed the ambiguous color on typical red or typical green objects based on the neural response of veridical red and green. This shift of neural response for the ambiguous color did not occur for nonsense objects. The modulation of neural responses was observed in visual areas (V3, V4, VO1, lateral occipital complex) involved in color and object processing, as well as frontal areas. This demonstrates that object memory influences wavelength information relatively early in the human visual system to produce subjective color vision. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Addressing Diversity in the Decade of Behavior: Focus on Women of Color.

Science.gov (United States)

Russo, Nancy Felipe; Vaz, Kim

2001-01-01

Discusses the lives of women of color, illustrating diversity-minded feminist principles that may inform research and program development related to other aspects of diversity. Notes perspectives and priorities of women of color in psychology. Considers why implementing feminist psychology's inclusive vision for research is a continuing struggle,…

Analyses of multi-color plant-growth light sources in achieving maximum photosynthesis efficiencies with enhanced color qualities.

Science.gov (United States)

Wu, Tingzhu; Lin, Yue; Zheng, Lili; Guo, Ziquan; Xu, Jianxing; Liang, Shijie; Liu, Zhuguagn; Lu, Yijun; Shih, Tien-Mo; Chen, Zhong

2018-02-19

An optimal design of light-emitting diode (LED) lighting that benefits both the photosynthesis performance for plants and the visional health for human eyes has drawn considerable attention. In the present study, we have developed a multi-color driving algorithm that serves as a liaison between desired spectral power distributions and pulse-width-modulation duty cycles. With the aid of this algorithm, our multi-color plant-growth light sources can optimize correlated-color temperature (CCT) and color rendering index (CRI) such that photosynthetic luminous efficacy of radiation (PLER) is maximized regardless of the number of LEDs and the type of photosynthetic action spectrum (PAS). In order to illustrate the accuracies of the proposed algorithm and the practicalities of our plant-growth light sources, we choose six color LEDs and German PAS for experiments. Finally, our study can help provide a useful guide to improve light qualities in plant factories, in which long-term co-inhabitance of plants and human beings is required.

Real-time vision systems

Energy Technology Data Exchange (ETDEWEB)

Johnson, R.; Hernandez, J.E.; Lu, Shin-yee [Lawrence Livermore National Lab., CA (United States)

1994-11-15

Many industrial and defence applications require an ability to make instantaneous decisions based on sensor input of a time varying process. Such systems are referred to as `real-time systems` because they process and act on data as it occurs in time. When a vision sensor is used in a real-time system, the processing demands can be quite substantial, with typical data rates of 10-20 million samples per second. A real-time Machine Vision Laboratory (MVL) was established in FY94 to extend our years of experience in developing computer vision algorithms to include the development and implementation of real-time vision systems. The laboratory is equipped with a variety of hardware components, including Datacube image acquisition and processing boards, a Sun workstation, and several different types of CCD cameras, including monochrome and color area cameras and analog and digital line-scan cameras. The equipment is reconfigurable for prototyping different applications. This facility has been used to support several programs at LLNL, including O Division`s Peacemaker and Deadeye Projects as well as the CRADA with the U.S. Textile Industry, CAFE (Computer Aided Fabric Inspection). To date, we have successfully demonstrated several real-time applications: bullet tracking, stereo tracking and ranging, and web inspection. This work has been documented in the ongoing development of a real-time software library.

Visual Perception with Color for Architectural Aesthetics

NARCIS (Netherlands)

Bittermann, M.S.; Ciftcioglu, O.

2016-01-01

Studies on computer-based visual perception and aesthetical judgment for architectural design are presented. In the model, both color and the geometric aspects of human vision are jointly taken into account, quantifying the perception of an individual object, as well as a scene consisting of several

The Visual Effects of Intraocular Colored Filters

Directory of Open Access Journals (Sweden)

Billy R. Hammond

2012-01-01

Full Text Available Modern life is associated with a myriad of visual problems, most notably refractive conditions such as myopia. Human ingenuity has addressed such problems using strategies such as spectacle lenses or surgical correction. There are other visual problems, however, that have been present throughout our evolutionary history and are not as easily solved by simply correcting refractive error. These problems include issues like glare disability and discomfort arising from intraocular scatter, photostress with the associated transient loss in vision that arises from short intense light exposures, or the ability to see objects in the distance through a veil of atmospheric haze. One likely biological solution to these more long-standing problems has been the use of colored intraocular filters. Many species, especially diurnal, incorporate chromophores from numerous sources (e.g., often plant pigments called carotenoids into ocular tissues to improve visual performance outdoors. This review summarizes information on the utility of such filters focusing on chromatic filtering by humans.

78 FR 63302 - Qualification of Drivers; Exemption Applications; Vision

Science.gov (United States)

2013-10-23

.... Ferris Mr. Ferris, 70, has had complete loss of vision in his right eye since 1991. The visual acuity in... sufficient vision to perform his driving tasks to operate a commercial vehicle.'' Mr. Ferris reported that he...

Event-Based Color Segmentation With a High Dynamic Range Sensor

Directory of Open Access Journals (Sweden)

Alexandre Marcireau

2018-04-01

Full Text Available This paper introduces a color asynchronous neuromorphic event-based camera and a methodology to process color output from the device to perform color segmentation and tracking at the native temporal resolution of the sensor (down to one microsecond. Our color vision sensor prototype is a combination of three Asynchronous Time-based Image Sensors, sensitive to absolute color information. We devise a color processing algorithm leveraging this information. It is designed to be computationally cheap, thus showing how low level processing benefits from asynchronous acquisition and high temporal resolution data. The resulting color segmentation and tracking performance is assessed both with an indoor controlled scene and two outdoor uncontrolled scenes. The tracking's mean error to the ground truth for the objects of the outdoor scenes ranges from two to twenty pixels.

Visual loss in a school for the blind in Nigeria.

Science.gov (United States)

Okoye, O I; Aghaji, A E; Ikojo, I N

2009-01-01

There are an estimated 1.4 million blind children worldwide, it has been observed that almost 90% of the so-called blind population (children inclusive) do not have total loss of visual function, but retain a degree of usable residual vision. The study aims to determined the sites and causes of visual loss in the students of a school for the blind in Nigeria, and also the proportion of those students who could benefit from low vision devices. Forty-five students of the school were examined using the standard World Health Organization/Prevention of blindness examination record for childhood blindness. Refraction and assessment for low vision devices were conducted, where necessary. Glaucoma/buphthalmos (22.2%) and corneal lesions (20%) were the major causes of vision loss. Six students (13.3%) benefited from spectacles and/or low vision devices. Glaucoma/buphthalmos is assuming great significance in this study population, though most of the causes of vision loss are avoidable (77.7%). There is need for low vision service in the schools for the blind in South East Nigeria.

Evaluation of reliability and validity of three dental color-matching devices.

Science.gov (United States)

Tsiliagkou, Aikaterini; Diamantopoulou, Sofia; Papazoglou, Efstratios; Kakaboura, Afrodite

2016-01-01

To assess the repeatability and accuracy of three dental color-matching devices under standardized and freehand measurement conditions. Two shade guides (Vita Classical A1-D4, Vita; and Vita Toothguide 3D-Master, Vita), and three color-matching devices (Easyshade, Vita; SpectroShade, MHT Optic Research; and ShadeVision, X-Rite) were used. Five shade tabs were selected from the Vita Classical A1-D4 (A2, A3.5, B1, C4, D3), and five from the Vita Toothguide 3D-Master (1M1, 2R1.5, 3M2, 4L2.5, 5M3) shade guides. Each shade tab was recorded 15 continuous, repeated times with each device under two different measurement conditions (standardized, and freehand). Both qualitative (color shade) and quantitative (L, a, and b) color characteristics were recorded. The color difference (ΔE) of each recorded value with the known values of the shade tab was calculated. The repeatability of each device was evaluated by the coefficient of variance. The accuracy of each device was determined by comparing the recorded values with the known values of the reference shade tab (one sample t test; α = 0.05). The agreement between the recorded shade and the reference shade tab was calculated. The influence of the parameters (devices and conditions) on the parameter ΔE was investigated (two-way ANOVA). Comparison of the devices was performed with Bonferroni pairwise post-hoc analysis. Under standardized conditions, repeatability of all three devices was very good, except for ShadeVision with Vita Classical A1-D4. Accuracy ranged from good to fair, depending on the device and the shade guide. Under freehand conditions, repeatability and accuracy for Easyshade and ShadeVision were negatively influenced, but not for SpectroShade, regardless of the shade guide. Based on the total of the color parameters assessed per device, SpectroShade was the most reliable of the three color-matching devices studied.

Image enhancement filters significantly improve reading performance for low vision observers

Science.gov (United States)

Lawton, T. B.

1992-01-01

As people age, so do their photoreceptors; many photoreceptors in central vision stop functioning when a person reaches their late sixties or early seventies. Low vision observers with losses in central vision, those with age-related maculopathies, were studied. Low vision observers no longer see high spatial frequencies, being unable to resolve fine edge detail. We developed image enhancement filters to compensate for the low vision observer's losses in contrast sensitivity to intermediate and high spatial frequencies. The filters work by boosting the amplitude of the less visible intermediate spatial frequencies. The lower spatial frequencies. These image enhancement filters not only reduce the magnification needed for reading by up to 70 percent, but they also increase the observer's reading speed by 2-4 times. A summary of this research is presented.

Visual Attention to Movement and Color in Children with Cortical Visual Impairment

Science.gov (United States)

Cohen-Maitre, Stacey Ann; Haerich, Paul

2005-01-01

This study investigated the ability of color and motion to elicit and maintain visual attention in a sample of children with cortical visual impairment (CVI). It found that colorful and moving objects may be used to engage children with CVI, increase their motivation to use their residual vision, and promote visual learning.

Computer vision and machine learning with RGB-D sensors

CERN Document Server

Shao, Ling; Kohli, Pushmeet

2014-01-01

This book presents an interdisciplinary selection of cutting-edge research on RGB-D based computer vision. Features: discusses the calibration of color and depth cameras, the reduction of noise on depth maps and methods for capturing human performance in 3D; reviews a selection of applications which use RGB-D information to reconstruct human figures, evaluate energy consumption and obtain accurate action classification; presents an approach for 3D object retrieval and for the reconstruction of gas flow from multiple Kinect cameras; describes an RGB-D computer vision system designed to assist t

Protanopia (red color-blindness) in medaka: a simple system for producing color-blind fish and testing their spectral sensitivity.

Science.gov (United States)

Homma, Noriko; Harada, Yumi; Uchikawa, Tamaki; Kamei, Yasuhiro; Fukamachi, Shoji

2017-02-06

Color perception is important for fish to survive and reproduce in nature. Visual pigments in the retinal photoreceptor cells are responsible for receiving light stimuli, but the function of the pigments in vivo has not been directly investigated in many animals due to the lack of color-blind lines and appropriate color-perception tests. In this study, we established a system for producing color-blind fish and testing their spectral sensitivity. First, we disrupted long-wavelength-sensitive (LWS) opsins of medaka (Oryzias latipes) using the CRISPR/Cas9 system to make red-color-blind lines. Single guide RNAs were designed using the consensus sequences between the paralogous LWSa and LWSb genes to simultaneously introduce double-frameshift mutations. Next, we developed a non-invasive and no-prior-learning test for spectral sensitivity by applying an optomotor response (OMR) test under an Okazaki Large Spectrograph (OLS), termed the O-O test. We constructed an electrical-rotary cylinder with black/white stripes, into which a glass aquarium containing one or more fish was placed under various monochromatic light conditions. The medaka were irradiated by the OLS every 10 nm, from wavelengths of 700 nm to 900 nm, and OMR was evaluated under each condition. We confirmed that the lws - medaka were indeed insensitive to red light (protanopia). While the control fish responded to wavelengths of up to 830 nm (λ = 830 nm), the lws - mutants responded up to λ = 740 nm; however, this difference was not observed after adaptation to dark: both the control and lws - fish could respond up to λ = 820 ~ 830 nm. These results suggest that the lws - mutants lost photopic red-cone vision, but retained scotopic rod vision. Considering that the peak absorption spectra (λ max ) of medaka LWSs are about 560 nm, but the light-adapted control medaka could respond behaviorally to light at λ = 830 nm, red-cone vision could cover an unexpectedly wide range of

[Research on developping the spectral dataset for Dunhuang typical colors based on color constancy].

Science.gov (United States)

Liu, Qiang; Wan, Xiao-Xia; Liu, Zhen; Li, Chan; Liang, Jin-Xing

2013-11-01

The present paper aims at developping a method to reasonably set up the typical spectral color dataset for different kinds of Chinese cultural heritage in color rendering process. The world famous wall paintings dating from more than 1700 years ago in Dunhuang Mogao Grottoes was taken as typical case in this research. In order to maintain the color constancy during the color rendering workflow of Dunhuang culture relics, a chromatic adaptation based method for developping the spectral dataset of typical colors for those wall paintings was proposed from the view point of human vision perception ability. Under the help and guidance of researchers in the art-research institution and protection-research institution of Dunhuang Academy and according to the existing research achievement of Dunhuang Research in the past years, 48 typical known Dunhuang pigments were chosen and 240 representative color samples were made with reflective spectral ranging from 360 to 750 nm was acquired by a spectrometer. In order to find the typical colors of the above mentioned color samples, the original dataset was devided into several subgroups by clustering analysis. The grouping number, together with the most typical samples for each subgroup which made up the firstly built typical color dataset, was determined by wilcoxon signed rank test according to the color inconstancy index comprehensively calculated under 6 typical illuminating conditions. Considering the completeness of gamut of Dunhuang wall paintings, 8 complementary colors was determined and finally the typical spectral color dataset was built up which contains 100 representative spectral colors. The analytical calculating results show that the median color inconstancy index of the built dataset in 99% confidence level by wilcoxon signed rank test was 3.28 and the 100 colors are distributing in the whole gamut uniformly, which ensures that this dataset can provide reasonable reference for choosing the color with highest

A deblocking algorithm based on color psychology for display quality enhancement

Science.gov (United States)

Yeh, Chia-Hung; Tseng, Wen-Yu; Huang, Kai-Lin

2012-12-01

This article proposes a post-processing deblocking filter to reduce blocking effects. The proposed algorithm detects blocking effects by fusing the results of Sobel edge detector and wavelet-based edge detector. The filtering stage provides four filter modes to eliminate blocking effects at different color regions according to human color vision and color psychology analysis. Experimental results show that the proposed algorithm has better subjective and objective qualities for H.264/AVC reconstructed videos when compared to several existing methods.

Atlantic salmon skin and fillet color changes effected by perimortem handling stress, rigor mortis, and ice storage.

Science.gov (United States)

Erikson, U; Misimi, E

2008-03-01

The changes in skin and fillet color of anesthetized and exhausted Atlantic salmon were determined immediately after killing, during rigor mortis, and after ice storage for 7 d. Skin color (CIE L*, a*, b*, and related values) was determined by a Minolta Chroma Meter. Roche SalmoFan Lineal and Roche Color Card values were determined by a computer vision method and a sensory panel. Before color assessment, the stress levels of the 2 fish groups were characterized in terms of white muscle parameters (pH, rigor mortis, and core temperature). The results showed that perimortem handling stress initially significantly affected several color parameters of skin and fillets. Significant transient fillet color changes also occurred in the prerigor phase and during the development of rigor mortis. Our results suggested that fillet color was affected by postmortem glycolysis (pH drop, particularly in anesthetized fillets), then by onset and development of rigor mortis. The color change patterns during storage were different for the 2 groups of fish. The computer vision method was considered suitable for automated (online) quality control and grading of salmonid fillets according to color.

Causes of Childhood Vision Impairment in the School for the Blind in Eritrea.

Science.gov (United States)

Gyawali, Rajendra; Moodley, Vanessa R

2017-12-01

Our study provides the much-needed evidence on causes of childhood blindness in Eritrea. This will assist authorities to plan appropriate strategies and implement preventive, curative, and rehabilitative services to address these causes of vision loss in children in this resource-limited country. This study aims to identify the causes of severe vision impairment and blindness in children attending the only school for the blind in Eritrea. All children enrolled in the school were examined, and the World Health Organization form for the examination of visually impaired children was used to record the data. Examination included visual acuity, refraction, anterior segment, and fundus assessment. Causes of vision loss for children with severe vision impairment (visual acuity blindness (visual acuity blindness. The major causes of vision loss were corneal scars (16.9%), cataract (12.7%), phthisis bulbi (11.3%), congenital eye deformities (11.3%), optic atrophy (9.3%), and presumed chorioretinal Toxoplasma scars (7.0%). Hereditary factors were the major known etiological category (15.5%) followed by the sequel of eye injuries (12.7%). Blindness due to vitamin A deficiency was not found, whereas infectious causes such as measles and ophthalmia neonatorum were relatively absent (one case each). Potentially avoidable causes of vision impairment were accounted for in 47.9% of children. This study provides the first direct evidence on childhood vision impairment in Eritrea. Despite the limitations, it is clearly shown that nearly half of the vision loss is due to avoidable causes. Thus, preventive public health strategies, specialist pediatric eye care, and rehabilitative services are recommended to address childhood vision impairment in Eritrea.

P1-9: Relationship between Color Shifts in Land's Two-Color Method and Higher- and Lower-Level Visual Information

Directory of Open Access Journals (Sweden)

Saki Iwaida

2012-10-01

Full Text Available Land's two-color method gives rise to apparent full-color perception, even though only two colors (e.g., red and gray are used. Previous studies indicate that chromatic adaptation, color memory, and inductive effects contribute to the shifts of color perception from real to illusory colors (e.g., Kuriki, 2006 Vision Research 46 3055–3066. This paper investigates the relationship between the color shifts induced by Land images and the skewness of the luminance histogram. In Experiment 1, several Land images are created based on a yellow ball, and the magnitude of the color shifts of the images are measured. The results of Experiment 1 show a significant correlation between the magnitude of the color shifts and skewness, suggesting that skewness is critical for the color shifts. In Experiment 2, we test the hypothesis that color shifts depends on just skewness; the color shifts should be invariant even if the Land images are scrambled. However, the results of Experiment 2 demonstrate that scrambled Land images exhibit less intense color shifts, suggesting that color shifts are determined by the object's overall shape or surface gloss, not just skewness. Taken together, we conclude that both low-level visual processes, such as those associated with luminance histogram skew, and high-level cognitive functions, such as object interpretation or understanding of surface gloss, are involved in the color shift of Land images.

The Functional Classification of Brain Damage-Related Vision Loss

Science.gov (United States)

Colenbrander, August

2009-01-01

This article provides a terminological framework to show the relationships among different types of visual deficits. It distinguishes between visual functions, which describe how the eye and the lower visual system function, and functional vision, which describes how a person functions. When visual functions are disturbed, the term "visual…

Homeostatic study of the effects of sportswear color on the contest outcome

Science.gov (United States)

Yuan, Jian-Qin; Liu, Timon Cheng-Yi; Wu, Ren-Le; Ruan, Chang-Xiong; He, Li-Mei; Liu, Song-Hao

2008-12-01

There are effects of sportswear color on the contest outcome. It has been explained from the psychological and perceptual viewpoints, respectively. It was studied by integrating the homeostatic theory of exercise training and autonomic nervous model of color vision in this paper. It was found that the effects of sportswear color on the contest outcome depend on autonomic nervous homeostasis (ANH). Color can be classified into hot color such as red, orange and yellow and cold color such as green, blue and violet. If the athletes have been in ANH, there are no effects of sportswear color on the contest outcome. If the autonomic nervous system is far from ANH due to exercise induced fatigue, wearing cold color had no predominance for cold-hot matches, and wearing white had no predominance for white-color matches.

Multiple spectral channels in branchiopods. I. Vision in dim light and neural correlates.

Science.gov (United States)

Lessios, Nicolas; Rutowski, Ronald L; Cohen, Jonathan H; Sayre, Marcel E; Strausfeld, Nicholas J

2018-05-22

Animals that have true color vision possess several spectral classes of photoreceptors. Pancrustaceans (Hexapoda+Crustacea) that integrate spectral information about their reconstructed visual world do so from photoreceptor terminals supplying their second optic neuropils, with subsequent participation of the third (lobula) and deeper centers (optic foci). Here, we describe experiments and correlative neural arrangements underlying convergent visual pathways in two species of branchiopod crustaceans that have to cope with a broad range of spectral ambience and illuminance in ephemeral pools, yet possess just two optic neuropils, the lamina and the optic tectum. Electroretinographic recordings and multimodel inference based on modeled spectral absorptance were used to identify the most likely number of spectral photoreceptor classes in their compound eyes. Recordings from the retina provide support for four color channels. Neuroanatomical observations resolve arrangements in their laminas that suggest signal summation at low light intensities, incorporating chromatic channels. Neuroanatomical observations demonstrate that spatial summation in the lamina of the two species are mediated by quite different mechanisms, both of which allow signals from several ommatidia to be pooled at single lamina monopolar cells. We propose that such summation provides sufficient signal for vision at intensities equivalent to those experienced by insects in terrestrial habitats under dim starlight. Our findings suggest that despite the absence of optic lobe neuropils necessary for spectral discrimination utilized by true color vision, four spectral photoreceptor classes have been maintained in Branchiopoda for vision at very low light intensities at variable ambient wavelengths that typify conditions in ephemeral freshwater habitats. © 2018. Published by The Company of Biologists Ltd.

PHYSIOTHERAPY OF BLIND AND LOW VISION INDIVIDUALS

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Alenka Tatjana Sterle

2002-12-01

Full Text Available Background. The authors present a preventive physiotherapy programme intended to improve the well-being of persons who have been blind or visually impaired since birth or experience partial or complete loss of vision later in life as a result of injury or disease.Methods. Different methods and techniques of physiotherapy, kinesitherapy and relaxation used in the rehabilitation of visually impaired persons are described.Results. The goals of timely physical treatment are to avoid unnecessary problems, such as improper posture, tension of the entire body, face and eyes, and deterioration of facial expression, that often accompany partial or complete loss of vision. Regular training improves functional skills, restores the skills that have been lost, and prevents the development of defects and consequent disorders of the locomotor apparatus.Conclusions. It is very difficult to change the life style and habits of blind and visually imapired persons. Especially elderly people who experience complete or partial loss of vision later in their lives are often left to their fate. Therefore blind and visually impaired persons of all age groups should be enrolled in a suitable rehabilitation programme that will improve the quality of their life.

Seeing red to being red: conserved genetic mechanism for red cone oil droplets and co-option for red coloration in birds and turtles.

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Twyman, Hanlu; Valenzuela, Nicole; Literman, Robert; Andersson, Staffan; Mundy, Nicholas I

2016-08-17

Avian ketocarotenoid pigments occur in both the red retinal oil droplets that contribute to colour vision and bright red coloration used in signalling. Turtles are the only other tetrapods with red retinal oil droplets, and some also display red carotenoid-based coloration. Recently, the CYP2J19 gene was strongly implicated in ketocarotenoid synthesis in birds. Here, we investigate CYP2J19 evolution in relation to colour vision and red coloration in reptiles using genomic and expression data. We show that turtles, but not crocodiles or lepidosaurs, possess a CYP2J19 orthologue, which arose via gene duplication before turtles and archosaurs split, and which is strongly and specifically expressed in the ketocarotenoid-containing retina and red integument. We infer that CYP2J19 initially functioned in colour vision in archelosaurs and conclude that red ketocarotenoid-based coloration evolved independently in birds and turtles via gene regulatory changes of CYP2J19 Our results suggest that red oil droplets contributed to colour vision in dinosaurs and pterosaurs. © 2016 The Author(s).

UV photoreceptors and UV-yellow wing pigments in Heliconius butterflies allow a color signal to serve both mimicry and intraspecific communication.

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Bybee, Seth M; Yuan, Furong; Ramstetter, Monica D; Llorente-Bousquets, Jorge; Reed, Robert D; Osorio, Daniel; Briscoe, Adriana D

2012-01-01

Mimetic wing coloration evolves in butterflies in the context of predator confusion. Unless butterfly eyes have adaptations for discriminating mimetic color variation, mimicry also carries a risk of confusion for the butterflies themselves. Heliconius butterfly eyes, which express recently duplicated ultraviolet (UV) opsins, have such an adaptation. To examine bird and butterfly color vision as sources of selection on butterfly coloration, we studied yellow wing pigmentation in the tribe Heliconiini. We confirmed, using reflectance and mass spectrometry, that only Heliconius use 3-hydroxy-DL-kynurenine (3-OHK), which looks yellow to humans but reflects both UV- and long-wavelength light, whereas butterflies in related genera have chemically unknown yellow pigments mostly lacking UV reflectance. Modeling of these color signals reveals that the two UV photoreceptors of Heliconius are better suited to separating 3-OHK from non-3-OHK spectra compared with the photoreceptors of related genera or birds. The co-occurrence of potentially enhanced UV vision and a UV-reflecting yellow wing pigment could allow unpalatable Heliconius private intraspecific communication in the presence of mimics. Our results are the best available evidence for the correlated evolution of a color signal and color vision. They also suggest that predator visual systems are error prone in the context of mimicry. © 2011 by The University of Chicago.

Dermatological Feasibility of Multimodal Facial Color Imaging Modality for Cross-Evaluation of Facial Actinic Keratosis

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Bae, Youngwoo; Son, Taeyoon; Nelson, J. Stuart; Kim, Jae-Hong; Choi, Eung Ho; Jung, Byungjo

2010-01-01

Background/Purpose Digital color image analysis is currently considered as a routine procedure in dermatology. In our previous study, a multimodal facial color imaging modality (MFCIM), which provides a conventional, parallel- and cross-polarization, and fluorescent color image, was introduced for objective evaluation of various facial skin lesions. This study introduces a commercial version of MFCIM, DermaVision-PRO, for routine clinical use in dermatology and demonstrates its dermatological feasibility for cross-evaluation of skin lesions. Methods/Results Sample images of subjects with actinic keratosis or non-melanoma skin cancers were obtained at four different imaging modes. Various image analysis methods were applied to cross-evaluate the skin lesion and, finally, extract valuable diagnostic information. DermaVision-PRO is potentially a useful tool as an objective macroscopic imaging modality for quick prescreening and cross-evaluation of facial skin lesions. Conclusion DermaVision-PRO may be utilized as a useful tool for cross-evaluation of widely distributed facial skin lesions and an efficient database management of patient information. PMID:20923462

Colors vision effect: learning and teaching strategies based on reading nature images

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Castillo, D.; Jiménez, Y.; Vivanco, O.; Cuenca, L.; Granda, C.; Sánchez, A.

2017-09-01

The present work shows the teaching and motivation of University students to think about optics and color effects. The methodology consists of studying the different optical phenomena that occur through the sunsets and then do a correlation of this information with the phenomena and optical effects of the color of class presentations; to determine the motivation and attention of students.

Computer Vision Utilization for Detection of Green House Tomato under Natural Illumination

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H Mohamadi Monavar

2013-02-01

Full Text Available Agricultural sector experiences the application of automated systems since two decades ago. These systems are applied to harvest fruits in agriculture. Computer vision is one of the technologies that are most widely used in food industries and agriculture. In this paper, an automated system based on computer vision for harvesting greenhouse tomatoes is presented. A CCD camera takes images from workspace and tomatoes with over 50 percent ripeness are detected through an image processing algorithm. In this research three color spaces including RGB, HSI and YCbCr and three algorithms including threshold recognition, curvature of the image and red/green ratio were used in order to identify the ripe tomatoes from background under natural illumination. The average error of threshold recognition, red/green ratio and curvature of the image algorithms were 11.82%, 10.03% and 7.95% in HSI, RGB and YCbCr color spaces, respectively. Therefore, the YCbCr color space and curvature of the image algorithm were identified as the most suitable for recognizing fruits under natural illumination condition.

[(Neurological CPC-59). A 65-year-old man with a history of gastric cancer who presented progressive loss of vision, memory loss and consciousness disturbance].

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Nohara, C; Matsumine, H; Suzuki, K; Saito, A; Ohtaka, M; Mori, H; Suda, K; Kondo, T; Hayakawa, M; Kanai, J; Mizuno, Y

1997-11-01

We report a 65-year-old man with progressive loss of vision and consciousness disturbance. The patient was well until his age of 63 when he was found to have a gastric cancer. He was treated by the tumor resection and chemotherapy; he was apparently well, but hepatic metastases were found in the next year (1996). In June, 1996, he noted an onset of blurred vision more on the left. He was admitted to the ophthalmology service of our hospital on July 14, 1996. His vision was 0.8 on the right and 0.15 on the left. He was treated with oral prednisolone with slight improvement. He was also found to have IgM kappa-type monoclonal gammopathy; Bence-Jones protein was positive and a bone marrow aspiration revealed that approximately 10% of bone marrow cells were atypical plasma cells. His vision had progressively got worse and he became blind by the end of October 1996. A chest X-ray and cranial CT scan revealed multiple abnormal nodular densities. In the middle of November 1996, he became confused, disoriented and agitated. His mental symptoms had progressively became worse, and a neurologic consultation was asked on December 10, 1996. Neurologic examination revealed that he was somnolent with decreased attention to his surroundings. He showed marked disorientation and memory loss. Higher cerebral functions appeared intact. He was able to recognize only light and dark. Pupils were moderately dilated with very sluggish light reflex remained. Vertical gaze was moderately restricted and horizontal nystagmus was noted upon left and right lateral gaze. The remaining of the neurologic examination were unremarkable. General physical examination revealed hepatosplenomegaly; the liver was palpable by 3 cm below the right costal margin. Laboratory examination revealed anemia (Hb10.1 g/dl) and thrombocytopenia (43,000/microliter). A cranial CT scan and MRI revealed a mass lesion in involving the chiasmatic and bilateral hypothalamic areas. The tumor showed intense homogeneous

Color vision in attention-deficit/hyperactivity disorder: a pilot visual evoked potential study.

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Kim, Soyeon; Banaschewski, Tobias; Tannock, Rosemary

2015-01-01

Individuals with attention-deficit/hyperactivity disorder (ADHD) are reported to manifest visual problems (including ophthalmological and color perception, particularly for blue-yellow stimuli), but findings are inconsistent. Accordingly, this study investigated visual function and color perception in adolescents with ADHD using color Visual Evoked Potentials (cVEP), which provides an objective measure of color perception. Thirty-one adolescents (aged 13-18), 16 with a confirmed diagnosis of ADHD, and 15 healthy peers, matched for age, gender, and IQ participated in the study. All underwent an ophthalmological exam, as well as electrophysiological testing color Visual Evoked Potentials (cVEP), which measured the latency and amplitude of the neural P1 response to chromatic (blue-yellow, red-green) and achromatic stimuli. No intergroup differences were found in the ophthalmological exam. However, significantly larger P1 amplitude was found for blue and yellow stimuli, but not red/green or achromatic stimuli, in the ADHD group (particularly in the medicated group) compared to controls. Larger amplitude in the P1 component for blue-yellow in the ADHD group compared to controls may account for the lack of difference in color perception tasks. We speculate that the larger amplitude for blue-yellow stimuli in early sensory processing (P1) might reflect a compensatory strategy for underlying problems including compromised retinal input of s-cones due to hypo-dopaminergic tone. Copyright © 2014 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

Atypical Wernicke′s syndrome sans encephalopathy with acute bilateral vision loss due to post-chiasmatic optic tract edema

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Soaham Dilip Desai

2014-01-01

Full Text Available A middle aged male presented with acute bilateral vision loss, 4 weeks after undergoing gastric bypass surgery for gastric carcinoma. He had normal sensorium, fundoscopy, normal pupillary reaction to light, but had mild opthalmoparesis and nystagmus with ataxia. Magnetic resonance imaging of the brain revealed post-chiasmatic optic tract edema along with other classical features of Wernicke′s syndrome. Thiamine supplementation leads to complete resolution of clinical as well as imaging findings. In appropriate clinical settings, a high index of suspicion and early treatment are essential for managing Wernicke′s syndrome even in patients with atypical clinical and imaging presentation.

Perceived overprotection, instrumental support and rehabilitation use in elders with vision loss: a longitudinal perspective.

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Cimarolli, Verena R; Boerner, Kathrin; Reinhardt, Joann P; Horowitz, Amy

2013-01-01

This study's purpose was to investigate changes in perceived overprotection - a problematic aspect of close relationships - over time in relationship to instrumental support receipt and vision rehabilitation service use in a sample of older adults with vision impairment. Participants were 584 older adults with chronic vision impairment who were interviewed three times over a 12-month period. Longitudinal data were analysed using a latent growth curve methodology to examine change over time in perceived overprotection and instrumental support in relation to vision rehabilitation service use. Self-reported levels of overprotection and receipt of instrumental support. Results. Over time perceived overprotection increased but not instrumental support. While perceived overprotection was positively associated with instrumental support initially, over time this relationship did not emerge. Perceived overprotection and instrumental support functioned as predictors of vision rehabilitation hours. However, over time vision rehabilitation service use did not influence these social supports. Perceived overprotection increases over time, yet this change is unaffected by rehabilitation service use and instrumental support. Both family members and elders need to be involved in the vision rehabilitation process and educated about how some level of independence can be regained.

Age-Related Psychophysical Changes and Low Vision

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Dagnelie, Gislin

2013-01-01

When considering the burden of visual impairment on aging individuals and society at large, it is important to bear in mind that vision changes are a natural aspect of aging. In this article, we consider vision changes that are part of normal aging, the prevalence of abnormal vision changes caused by disorders of the visual system, and the anticipated incidence and impact of visual impairment as the US population ages. We then discuss the services available to reduce the impact of vision loss, and the extent to which those services can and should be improved, not only to be better prepared for the anticipated increase in low vision over the coming decades, but also to increase the awareness of interactions between visual impairment and comorbidities that are common among the elderly. Finally, we consider how to promote improved quality, availability, and acceptance of low vision care to lessen the impact of visual impairment on individuals, and its burden on society. PMID:24335074

A Software Application to Detect Dental Color

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Dan SÎMPĂLEAN

2015-09-01

Full Text Available Choosing dental color for missing teeth or tooth reconstruction is an important step and it usually raises difficulties for dentists due to a significant amount of subjective factors that can influence the color selection. Dental reconstruction presumes the combination between dentistry and chromatics, thus implying important challenges. Purpose: The aim of this study was to develop and implement a software application for detecting dental color to come to the aid of dentists and largely to remove the inherent subjectiveness of the human vision. Basic Methods: The implemented application was named Color Detection and the application’s source code is written using the C++ language. During application development, for creating the GUI (graphical user interface the wxWidgets 2.8 library it was used. Results: The application displays the average color of the selected area of interest, the reference color from the key collection existent in the program and also the degree of similarity between the original (the selected area of interest and the nearest reference key. This degree of similarity is expressed as a percentage. Conclusions: The Color Detection Program, by eliminating the subjectivity inherent to human sight, can help the dentist to select an appropriate dental color with precision.

Evaluation of a color fused dual-band NVG

NARCIS (Netherlands)

Hogervorst, M.A.; Toet, A.

2009-01-01

We designed and evaluated a dual-band Night Vision Goggles sensor system. The sensor system consists of two optically aligned NVGs fitted with filters splitting the sensitive range into a visual and a near-infrared band. The Color-the-night technique (Hogervorst & Toet, FUSION2008) was used to fuse

Color preference in red–green dichromats

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Álvaro, Leticia; Moreira, Humberto; Lillo, Julio; Franklin, Anna

2015-01-01

Around 2% of males have red–green dichromacy, which is a genetic disorder of color vision where one type of cone photoreceptor is missing. Here we investigate the color preferences of dichromats. We aim (i) to establish whether the systematic and reliable color preferences of normal trichromatic observers (e.g., preference maximum at blue, minimum at yellow-green) are affected by dichromacy and (ii) to test theories of color preference with a dichromatic sample. Dichromat and normal trichromat observers named and rated how much they liked saturated, light, dark, and focal colors twice. Trichromats had the expected pattern of preference. Dichromats had a reliable pattern of preference that was different to trichromats, with a preference maximum rather than minimum at yellow and a much weaker preference for blue than trichromats. Color preference was more affected in observers who lacked the cone type sensitive to long wavelengths (protanopes) than in those who lacked the cone type sensitive to medium wavelengths (deuteranopes). Trichromats’ preferences were summarized effectively in terms of cone-contrast between color and background, and yellow-blue cone-contrast could account for dichromats’ pattern of preference, with some evidence for residual red–green activity in deuteranopes’ preference. Dichromats’ color naming also could account for their color preferences, with colors named more accurately and quickly being more preferred. This relationship between color naming and preference also was present for trichromat males but not females. Overall, the findings provide novel evidence on how dichromats experience color, advance the understanding of why humans like some colors more than others, and have implications for general theories of aesthetics. PMID:26170287

Correlation between three color coordinates of human teeth

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Lee, Yong-Keun

2014-11-01

The objective was to determine whether there were significant correlations in the three color coordinates within each of two color coordinate systems, such as the Commission Internationale de l'Eclairage (CIE) L*a*b* system, and the lightness, chroma, and hue angle system, of human vital teeth. The color of six maxillary and six mandibular anterior teeth was measured by the Shade Vision System. Pearson correlations between each pair of the color coordinates were determined (α=0.01). The influence of two color coordinates on the other color coordinate was determined with a multiple regression analysis (α=0.01). Based on correlation analyses, all the color coordinate pairs showed significant correlations except for the chroma and hue angle pair. The CIE L* was negatively correlated with the CIE a*, b*, and chroma, but positively correlated with the hue angle. The CIE a* was positively correlated with the CIE b* and chroma. Tooth color coordinates were correlated each other. Lighter teeth were less chromatic both in the CIE a* and b* coordinates. Therefore, it was postulated that the three color coordinates of human teeth were harmonized within certain color attribute ranges, and a lack of correlations in these coordinates might indicate external/internal discolorations and/or anomalies of teeth.

Highly polymorphic colour vision in a New World monkey with red facial skin, the bald uakari (Cacajao calvus).

Science.gov (United States)

Corso, Josmael; Bowler, Mark; Heymann, Eckhard W; Roos, Christian; Mundy, Nicholas I

2016-04-13

Colour vision is highly variable in New World monkeys (NWMs). Evidence for the adaptive basis of colour vision in this group has largely centred on environmental features such as foraging benefits for differently coloured foods or predator detection, whereas selection on colour vision for sociosexual communication is an alternative hypothesis that has received little attention. The colour vision of uakaris (Cacajao) is of particular interest because these monkeys have the most dramatic red facial skin of any primate, as well as a unique fission/fusion social system and a specialist diet of seeds. Here, we investigate colour vision in a wild population of the bald uakari,C. calvus, by genotyping the X-linked opsin locus. We document the presence of a polymorphic colour vision system with an unprecedented number of functional alleles (six), including a novel allele with a predicted maximum spectral sensitivity of 555 nm. This supports the presence of strong balancing selection on different alleles at this locus. We consider different hypotheses to explain this selection. One possibility is that trichromacy functions in sexual selection, enabling females to choose high-quality males on the basis of red facial coloration. In support of this, there is some evidence that health affects facial coloration in uakaris, as well as a high prevalence of blood-borne parasitism in wild uakari populations. Alternatively, the low proportion of heterozygous female trichromats in the population may indicate selection on different dichromatic phenotypes, which might be related to cryptic food coloration. We have uncovered unexpected diversity in the last major lineage of NWMs to be assayed for colour vision, which will provide an interesting system to dissect adaptation of polymorphic trichromacy. © 2016 The Author(s).

Representing vision and blindness.

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Ray, Patrick L; Cox, Alexander P; Jensen, Mark; Allen, Travis; Duncan, William; Diehl, Alexander D

2016-01-01

There have been relatively few attempts to represent vision or blindness ontologically. This is unsurprising as the related phenomena of sight and blindness are difficult to represent ontologically for a variety of reasons. Blindness has escaped ontological capture at least in part because: blindness or the employment of the term 'blindness' seems to vary from context to context, blindness can present in a myriad of types and degrees, and there is no precedent for representing complex phenomena such as blindness. We explore current attempts to represent vision or blindness, and show how these attempts fail at representing subtypes of blindness (viz., color blindness, flash blindness, and inattentional blindness). We examine the results found through a review of current attempts and identify where they have failed. By analyzing our test cases of different types of blindness along with the strengths and weaknesses of previous attempts, we have identified the general features of blindness and vision. We propose an ontological solution to represent vision and blindness, which capitalizes on resources afforded to one who utilizes the Basic Formal Ontology as an upper-level ontology. The solution we propose here involves specifying the trigger conditions of a disposition as well as the processes that realize that disposition. Once these are specified we can characterize vision as a function that is realized by certain (in this case) biological processes under a range of triggering conditions. When the range of conditions under which the processes can be realized are reduced beyond a certain threshold, we are able to say that blindness is present. We characterize vision as a function that is realized as a seeing process and blindness as a reduction in the conditions under which the sight function is realized. This solution is desirable because it leverages current features of a major upper-level ontology, accurately captures the phenomenon of blindness, and can be

Hyperspectral imaging of cuttlefish camouflage indicates good color match in the eyes of fish predators.

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Chiao, Chuan-Chin; Wickiser, J Kenneth; Allen, Justine J; Genter, Brock; Hanlon, Roger T

2011-05-31

Camouflage is a widespread phenomenon throughout nature and an important antipredator tactic in natural selection. Many visual predators have keen color perception, and thus camouflage patterns should provide some degree of color matching in addition to other visual factors such as pattern, contrast, and texture. Quantifying camouflage effectiveness in the eyes of the predator is a challenge from the perspectives of both biology and optical imaging technology. Here we take advantage of hyperspectral imaging (HSI), which records full-spectrum light data, to simultaneously visualize color match and pattern match in the spectral and the spatial domains, respectively. Cuttlefish can dynamically camouflage themselves on any natural substrate and, despite their colorblindness, produce body patterns that appear to have high-fidelity color matches to the substrate when viewed directly by humans or with RGB images. Live camouflaged cuttlefish on natural backgrounds were imaged using HSI, and subsequent spectral analysis revealed that most reflectance spectra of individual cuttlefish and substrates were similar, rendering the color match possible. Modeling color vision of potential di- and trichromatic fish predators of cuttlefish corroborated the spectral match analysis and demonstrated that camouflaged cuttlefish show good color match as well as pattern match in the eyes of fish predators. These findings (i) indicate the strong potential of HSI technology to enhance studies of biological coloration and (ii) provide supporting evidence that cuttlefish can produce color-coordinated camouflage on natural substrates despite lacking color vision.

Fault-Tolerant Vision for Vehicle Guidance in Agriculture

DEFF Research Database (Denmark)

Blas, Morten Rufus

, and aiding sensors such as GPS provide means to detect and isolate single faults in the system. In addition, learning is employed to adapt the system to variational changes in the natural environment. 3D vision is enhanced by learning texture and color information. Intensity gradients on small neighborhoods...... dropout of 3D vision, faults in classification, or other defects, redundant information should be utilized. Such information can be used to diagnose faulty behavior and to temporarily continue operation with a reduced set of sensors when faults or artifacts occur. Additional sensors include GPS receivers...... and inertial sensors. To fully utilize the possibilities in 3D vision, the system must also be able to learn and adapt to changing environments. By learning features of the environment new diagnostic relations can be generated by creating redundant feed-forward information about crop location. Also, by mapping...

Vision and vision-related outcome measures in multiple sclerosis

DEFF Research Database (Denmark)

Balcer, Laura J; Miller, David H; Reingold, Stephen C

2015-01-01

Visual impairment is a key manifestation of multiple sclerosis. Acute optic neuritis is a common, often presenting manifestation, but visual deficits and structural loss of retinal axonal and neuronal integrity can occur even without a history of optic neuritis. Interest in vision in multiple...... sclerosis is growing, partially in response to the development of sensitive visual function tests, structural markers such as optical coherence tomography and magnetic resonance imaging, and quality of life measures that give clinical meaning to the structure-function correlations that are unique...... of investigators involved in the development and study of visual outcomes in multiple sclerosis, which had, as its overriding goals, to review the state of the field and identify areas for future research. We review data and principles to help us understand the importance of vision as a model for outcomes...

Visual rehabilitation: visual scanning, multisensory stimulation and vision restoration trainings

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Neil M. Dundon

2015-07-01

Full Text Available Neuropsychological training methods of visual rehabilitation for homonymous vision loss caused by postchiasmatic damage fall into two fundamental paradigms: compensation and restoration. Existing methods can be classified into three groups: Visual Scanning Training (VST, Audio-Visual Scanning Training (AViST and Vision Restoration Training (VRT. VST and AViST aim at compensating vision loss by training eye scanning movements, whereas VRT aims at improving lost vision by activating residual visual functions by training light detection and discrimination of visual stimuli. This review discusses the rationale underlying these paradigms and summarizes the available evidence with respect to treatment efficacy. The issues raised in our review should help guide clinical care and stimulate new ideas for future research uncovering the underlying neural correlates of the different treatment paradigms. We propose that both local within-system interactions (i.e., relying on plasticity within peri-lesional spared tissue and changes in more global between-system networks (i.e., recruiting alternative visual pathways contribute to both vision restoration and compensatory rehabilitation that ultimately have implications for the rehabilitation of cognitive functions.

77 FR 33017 - Qualification of Drivers; Exemption Applications; Vision

Science.gov (United States)

2012-06-04

.... Molenaar Mr. Molenaar, 59, has complete loss of vision in his right eye since childhood. The best corrected... examination in 2011, his ophthalmologist noted, ``It is my opinion that Gerardus C. Molenaar has sufficient vision to perform driving tasks required to operate a commercial vehicle.'' Mr. Molenaar reported that he...

Color change, phenotypic plasticity, and camouflage

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Martin eStevens

2016-05-01

Full Text Available The ability to change appearance over a range of timescales is widespread in nature, existing in many invertebrate and vertebrate groups. This can include color change occurring in seconds, minutes, and hours, to longer term changes associated with phenotypic plasticity and development. A major function is for camouflage against predators because color change and plasticity enables animals to match their surroundings and potentially reduce the risk of predation. Recently, we published findings (Stevens et al. 2014a showing how shore crabs can change their appearance and better match the background to predator vision in the short term. This, coupled with a number of past studies, emphasizes the potential that animals have to modify their appearance for camouflage. However, the majority of studies on camouflage and color plasticity have focused on a small number of species capable of unusually rapid changes. There are many broad questions that remain about the nature, mechanisms, evolution, and adaptive value of color change and plasticity for concealment. Here, I discuss past work and outline six questions relating to color change and plasticity, as well as major avenues for future work.

Vision related quality of life in patients with type 2 diabetes in the EUROCONDOR trial.

Science.gov (United States)

Trento, Marina; Durando, Olga; Lavecchia, Sonia; Charrier, Lorena; Cavallo, Franco; Costa, Miguel Angelo; Hernández, Cristina; Simó, Rafael; Porta, Massimo

2017-07-01

To evaluate vision related quality of life in the patients enrolled in The European Consortium for the Early Treatment of Diabetic Retinopathy, a clinical trial on prevention of diabetic retinopathy. Four-hundred-forty-nine patients, 153 women, with type 2 Diabetes and no or mild diabetic retinopathy were enrolled in a 2-year multicenter randomized controlled trial. The 25-item National Eye Institute Visual Functioning Questionnaire was used to explore 12 subscales of vision related quality of life. The patients were 62.8 ± 6.7 years old and had 11.1 ± 5.6 years known disease duration. Diabetic retinopathy was absent in 193 (43.0 %) and mild in 256 (57.0 %). Patients without diabetic retinopathy were older, had shorter diabetes duration and used less insulin and glucose-lowering agents but did not differ by gender, best corrected visual acuity or any subscale, except vision specific mental health and vision specific role difficulties. Patients with reduced retinal thickness at the ganglion cell layer (n = 36) did not differ for diabetic retinopathy but were older, had lower best corrected visual acuity and worse scores for ocular pain, color vision and peripheral vision. On multivariable analysis, worse scores for general vision remained associated with reduced retinal thickness, diabetes duration and best corrected visual acuity, and scores for visual specific mental health with diabetic retinopathy and lower best corrected visual acuity. Visual specific role difficulties were only associated with reduced best corrected visual acuity. Scores for driving decreased among females, with worsening of Hemoglobin A1c and best corrected visual acuity. Color vision depended only on reduced retinal thickness, and peripheral vision on both reduced thickness and best corrected visual acuity. The National Eye Institute Visual Functioning Questionnaire could detect subtle changes in patients' perception of visual function, despite absent/minimal diabetic

Automated Vision Test Development and Validation

Science.gov (United States)

2016-11-01

crystal display monitor (NEC Multisync, P232W) at 1920x1080 resolution. Proper calibration was confirmed using a spot photometer/colorimeter (X-Rite i1...visual input to the right and left eye was achieved using liquid crystal display shuttered glasses (NVIDIA 3D Vision 2). The stereo target (Figure 4...threshold on the automated tasks. • Subjects had a lower (better) threshold on color testing for all cone types using the OCCT due to a ceiling

Creating photorealistic virtual model with polarization-based vision system

Science.gov (United States)

Shibata, Takushi; Takahashi, Toru; Miyazaki, Daisuke; Sato, Yoichi; Ikeuchi, Katsushi

2005-08-01

Recently, 3D models are used in many fields such as education, medical services, entertainment, art, digital archive, etc., because of the progress of computational time and demand for creating photorealistic virtual model is increasing for higher reality. In computer vision field, a number of techniques have been developed for creating the virtual model by observing the real object in computer vision field. In this paper, we propose the method for creating photorealistic virtual model by using laser range sensor and polarization based image capture system. We capture the range and color images of the object which is rotated on the rotary table. By using the reconstructed object shape and sequence of color images of the object, parameter of a reflection model are estimated in a robust manner. As a result, then, we can make photorealistic 3D model in consideration of surface reflection. The key point of the proposed method is that, first, the diffuse and specular reflection components are separated from the color image sequence, and then, reflectance parameters of each reflection component are estimated separately. In separation of reflection components, we use polarization filter. This approach enables estimation of reflectance properties of real objects whose surfaces show specularity as well as diffusely reflected lights. The recovered object shape and reflectance properties are then used for synthesizing object images with realistic shading effects under arbitrary illumination conditions.

'Everest' Panorama; 20-20 Vision

Science.gov (United States)

2005-01-01

[figure removed for brevity, see original site] 'Everest' Panorama 20-20 Vision (QTVR) [figure removed for brevity, see original site] 'Everest' Panorama Animation If a human with perfect vision donned a spacesuit and stepped onto the martian surface, the view would be as clear as this sweeping panorama taken by NASA's Mars Exploration Rover Spirit. That's because the rover's panoramic camera has the equivalent of 20-20 vision. Earthlings can take a virtual tour of the scenery by zooming in on their computer screens many times to get a closer look at, say, a rock outcrop or a sand drift, without losing any detail. This level of clarity is unequaled in the history of Mars exploration. It took Spirit three days, sols 620 to 622 (Oct. 1 to Oct. 3, 2005), to acquire all the images combined into this mosaic, called the 'Everest Panorama,' looking outward in every direction from the true summit of 'Husband Hill.' During that period, the sky changed in color and brightness due to atmospheric dust variations, as shown in contrasting sections of this mosaic. Haze occasionally obscured the view of the hills on the distant rim of Gusev Crater 80 kilometers (50 miles) away. As dust devils swooped across the horizon in the upper right portion of the panorama, the robotic explorer changed the filters on the camera from red to green to blue, making the dust devils appear red, green, and blue. In reality, the dust devils are similar in color to the reddish-brown soils of Mars. No attempt was made to 'smooth' the sky in this mosaic, as has been done in other panoramic-camera mosaics to simulate the view one would get by taking in the landscape all at once. The result is a sweeping vista that allows viewers to observe weather changes on Mars. The summit of Husband Hill is a broad plateau of rock outcrops and windblown drifts about 100 meters (300 feet) higher than the surrounding plains of Gusev Crater. In the distance, near the center of the mosaic, is the 'South Basin,' the

Color Vision Changes and Effects of High Contrast Visor Use at Simulated Cabin Altitudes

Science.gov (United States)

2016-06-08

Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person...Morris DS, Kalson NS, Wright AD, Imray CHE, et al. Changes to colour vision on exposure to high altitude. J R Army Med Corps. 2011; 157(1):107-109...4. Richalet JP, Duval-Arnould G, Darnaud B, Keromes A, Rutgers V. Modification of colour vision in the green/red axis in acute and chronic

Case Report: Use of Sports and Performance Vision Training to Benefit a Low-vision Patient's Function.

Science.gov (United States)

Laby, Daniel M

2018-05-17

Despite our inability to attenuate the course of many ocular diseases that can ultimately lead to loss or significantly decreased visual function, this report describes a potential technique to aid such patients in maximizing the use of the vision that remains. The aim of this study was to demonstrate the applicability of utilizing sports vision training to improve objective and subjective visuomotor function in a low-vision patient. A 37-year-old woman with Usher syndrome presented with reduced central visual acuity and visual field. Although we were unable to reverse the damage resulting from her diagnosis, we were able to improve the use of the remaining vision. A 27 to 31% improvement in hand-eye coordination was achieved along with a 41% improvement in object tracking and visual concentration. Most importantly, following the 14-week training period, there was also a subjective improvement in the patient's appreciation of her visual ability. The sports vision literature cites many examples in which sports vision training is useful in improving visuomotor and on-field performance. We hypothesized that these techniques may be used to aid not only athletes but also patients with low vision. Despite suffering from reduced acuity and a limited visual field, these patients often still have a significant amount of vision ability that can be used to guide motor actions. Using techniques to increase the efficient use of this remaining vision may reduce the impact of the reduced visual function and aid in activities of daily living.

Research of principles for estimating the freshness of meat products by color analysis method

Science.gov (United States)

Gorbunova, Elena V.; Chertov, Aleksandr N.; Petukhova, Daria B.; Alekhin, Artem A.; Korotaev, Valery V.

2015-03-01

Color is one of the most important metrics of foodstuffs quality. It gives an indication of freshness, ingredient composition as well as about the presence or absence of falsification. Most often, the color is estimated visually, and thus, the evaluation is subjective. By automating the color analysis a wide application for this method could be found. The aim of this research is to study the principles of color analysis as applied to the task of evaluating the freshness of meat products using modern machine vision systems. From a scientific point of view, the color of meat depends on the proportion of myoglobin and its derivatives. It's the main pigment that characterizes the freshness of meat. Further color of meat can change due to oxidation of myoglobin during storage. Myoglobin exists in three forms. There are oxygenated form, oxidized form and form without oxygen. The meat color changes not only due to the conversion of one form into another. The content of amino acids and ammonia are another characteristics and constant signs of meat products spoilage. The paper presents the results of meat color computer simulation based on data on the content of various forms of myoglobin in different proportions. The spectral characteristic of the light source used to illuminate the meat sample is taken into account. Also the experimental studies were conducted using samples of beef. As a result the correlations between said biochemical indicators of the quality and color of the meat obtained with the help of machine vision system were found.

VISION- REQUIREMENT FOR A SUCCESSFUL LEADER

Directory of Open Access Journals (Sweden)

Angela - Olimpia Lobonea (Oltean

2014-12-01

Full Text Available These people were called in the past chiefs, rulers. Now they are known as leaders. After management by objectives, strategic planning, project organization, this concept appears as a tool called "fourth generation". It is called VISION. Leadership and vision exist in the actual sense, which has become modern a few decades ago, managing to gather during this time a variety of scientific instruments. The connection between these two domains creates a certain type of leader, the visionary leader. The hypothesis from which we start is that all active leaders have a vision of what needs to be accomplished, and the inability to predict something that could be provided involves loss the capacity of the leader. Without vision, the energy reaches the lowest quotas, production decreases, terms limits are exceeded and human resources begin to dissipate.. The conclusion is that visionary leaders are endowed with multiple attributes (multiple intelligence, even if sometimes the role of intuition and unconscious in building vision at the expense of reason that is based on experience and facts is exaggerated.

Predicting Visual Disability in Glaucoma With Combinations of Vision Measures.

Science.gov (United States)

Lin, Stephanie; Mihailovic, Aleksandra; West, Sheila K; Johnson, Chris A; Friedman, David S; Kong, Xiangrong; Ramulu, Pradeep Y

2018-04-01

We characterized vision in glaucoma using seven visual measures, with the goals of determining the dimensionality of vision, and how many and which visual measures best model activity limitation. We analyzed cross-sectional data from 150 older adults with glaucoma, collecting seven visual measures: integrated visual field (VF) sensitivity, visual acuity, contrast sensitivity (CS), area under the log CS function, color vision, stereoacuity, and visual acuity with noise. Principal component analysis was used to examine the dimensionality of vision. Multivariable regression models using one, two, or three vision tests (and nonvisual predictors) were compared to determine which was best associated with Rasch-analyzed Glaucoma Quality of Life-15 (GQL-15) person measure scores. The participants had a mean age of 70.2 and IVF sensitivity of 26.6 dB, suggesting mild-to-moderate glaucoma. All seven vision measures loaded similarly onto the first principal component (eigenvectors, 0.220-0.442), which explained 56.9% of the variance in vision scores. In models for GQL scores, the maximum adjusted- R 2 values obtained were 0.263, 0.296, and 0.301 when using one, two, and three vision tests in the models, respectively, though several models in each category had similar adjusted- R 2 values. All three of the best-performing models contained CS. Vision in glaucoma is a multidimensional construct that can be described by several variably-correlated vision measures. Measuring more than two vision tests does not substantially improve models for activity limitation. A sufficient description of disability in glaucoma can be obtained using one to two vision tests, especially VF and CS.

Age of Onset of Blindness and the Development of the Semantics of Color Names.

Science.gov (United States)

Marmor, Gloria Strauss

The relationship between age of onset of blindness and development of knowledge of color relations was examined with 16 college students who had been born totally blind, 16 who had been blinded totally at approximately 15 years of age, and 16 who had normal vision. Ss were asked to judge the similarities between color names, and judgments were…

Real-time three-dimensional surface measurement by color encoded light projection

International Nuclear Information System (INIS)

Chen, S. Y.; Li, Y. F.; Guan, Q.; Xiao, G.

2006-01-01

Existing noncontact methods for surface measurement suffer from the disadvantages of poor reliability, low scanning speed, or high cost. The authors present a method for real-time three-dimensional data acquisition by a color-coded vision sensor composed of common components. The authors use a digital projector controlled by computer to generate desired color light patterns. The unique indexing of the light codes is a key problem and is solved in this study so that surface perception can be performed with only local pattern analysis of the neighbor color codes in a single image. Experimental examples and performance analysis are provided

Revisiting Postoperative Vision Loss following Non-Ocular Surgery: A Short Review of Etiology and Legal Considerations

Directory of Open Access Journals (Sweden)

Ehud Mendel

2017-06-01

Full Text Available Postoperative vision loss (POVL following non-ocular surgery is a serious complication where the causes are not fully understood. Studies have identified several causes of POVL as well as risk factors and prevention strategies. POVL research is made difficult by the fact that cases are often subject to malpractice claims, resulting in a lack of public access to case reports. This literature review was conducted in order to identify legal issues as a major barrier to studying POVL and address how this affects current knowledge. Informed consent provides an opportunity to overcome legal challenges by reducing malpractice litigation through educating the patient on this outcome. Providing pertinent information regarding POVL during the informed consent process has potential to reduce malpractice claims and increase available clinical information.

Color vision in ADHD: part 2--does attention influence color perception?

Science.gov (United States)

Kim, Soyeon; Al-Haj, Mohamed; Fuller, Stuart; Chen, Samantha; Jain, Umesh; Carrasco, Marisa; Tannock, Rosemary

2014-10-24

To investigate the impact of exogenous covert attention on chromatic (blue and red) and achromatic visual perception in adults with and without Attention Deficit Hyperactivity Disorder (ADHD). Exogenous covert attention, which is a transient, automatic, stimulus-driven form of attention, is a key mechanism for selecting relevant information in visual arrays. 30 adults diagnosed with ADHD and 30 healthy adults, matched on age and gender, performed a psychophysical task designed to measure the effects of exogenous covert attention on perceived color saturation (blue, red) and contrast sensitivity. The effects of exogenous covert attention on perceived blue and red saturation levels and contrast sensitivity were similar in both groups, with no differences between males and females. Specifically, exogenous covert attention enhanced the perception of blue saturation and contrast sensitivity, but it had no effect on the perception of red saturation. The findings suggest that exogenous covert attention is intact in adults with ADHD and does not account for the observed impairments in the perception of chromatic (blue and red) saturation.

Psychophysical Measurements of Luminance Contrast Sensitivity and Color Discrimination with Transparent and Blue-Light Filter Intraocular Lenses.

Science.gov (United States)

da Costa, Marcelo Fernandes; Júnior, Augusto Paranhos; Lottenberg, Claudio Luiz; Castro, Leonardo Cunha; Ventura, Dora Fix

2017-12-01

The purpose of this study was to measure luminance contrast sensitivity and color vision thresholdfs in normal subjects using a blue light filter lens and transparent intraocular lens material. Monocular luminance grating contrast sensitivity was measured with Psycho for Windows (version 2.36; Cambridge Research Systems) at 3.0, 6.0, 12.0, 20.0, and 30.0 cycles per degree of visual angle (cpd) in 15 normal subjects (eight female), with a mean age of 21.6 years (SD = 3.8 years). Chromatic discrimination was assessed with the Cambridge colour test (CCT) along the protan, deutan, and tritan color confusion axes. Both tests were performed in a darkened room under two situations: with a transparent lens and with blue light filter lens. Subjective impressions were taken by subjects regarding their visual experience under both conditions. No difference was found between the luminance contrast sensitivity measured with transparent and blue light filter. However, 13/15 (87%) of the subjects reported more comfortable vision with the blue filter. In the color vision test, tritan thresholds were significantly higher for the blue filter compared with the transparent filter (p = 0.003). For protan and deutan thresholds no differences were found. Blue-yellow color vision is impaired with the blue light filter, and no impairment occurs with the transparent filter. No significant differences in thresholds were found in the luminance contrast sensitivity comparing the blue light and transparent filters. The impact of short wavelength light filtering on intrinsically photosensitive retinal ganglion cells is also discussed.

The incidence of color blindness among some school children of Pokhara, Western Nepal.

Science.gov (United States)

Niroula, D R; Saha, C G

2010-03-01

The incidence of color blindness varies from race to race and different in different geographical area. Since, there is no such report about the prevalence of color blindness in the western part of Nepal, the present study had been conducted to find out the incidence of color blindness among school children of Pokhara city, western Nepal. Participant's (n=964, 474 boys, 490 girls, age group 10 to 19 years) color vision was tested by using Ishihara chart (38 plates). Among 474 boys, 18 boys were color blind with the prevalence of 3.8%. None of girls were found to be color blind. Out of 18 color blind boys, nine, six and three boys were the victims of deuteranopia, deuteranomaly and protanomaly respectively. The incidence of color blindness were more amongst the Darji (14.3%) and Newar (9.1%) ethnic groups.

The Verriest Lecture: Color lessons from space, time, and motion

Science.gov (United States)

Shevell, Steven K.

2012-01-01

The appearance of a chromatic stimulus depends on more than the wavelengths composing it. The scientific literature has countless examples showing that spatial and temporal features of light influence the colors we see. Studying chromatic stimuli that vary over space, time or direction of motion has a further benefit beyond predicting color appearance: the unveiling of otherwise concealed neural processes of color vision. Spatial or temporal stimulus variation uncovers multiple mechanisms of brightness and color perception at distinct levels of the visual pathway. Spatial variation in chromaticity and luminance can change perceived three-dimensional shape, an example of chromatic signals that affect a percept other than color. Chromatic objects in motion expose the surprisingly weak link between the chromaticity of objects and their physical direction of motion, and the role of color in inducing an illusory motion direction. Space, time and motion – color’s colleagues – reveal the richness of chromatic neural processing. PMID:22330398

Color-based free-space segmentation using online disparity-supervised learning

NARCIS (Netherlands)

Sanberg, W.P.; Dubbelman, G.; de With, P.H.N.

2015-01-01

This work contributes to vision processing for Advanced Driver Assist Systems (ADAS) and intelligent vehicle applications. We propose a color-only stixel segmentation framework to segment traffic scenes into free, drivable space and obstacles, which has a reduced latency to improve the real-time

Bio-Inspired Asynchronous Pixel Event Tricolor Vision Sensor.

Science.gov (United States)

Lenero-Bardallo, Juan Antonio; Bryn, D H; Hafliger, Philipp

2014-06-01

This article investigates the potential of the first ever prototype of a vision sensor that combines tricolor stacked photo diodes with the bio-inspired asynchronous pixel event communication protocol known as Address Event Representation (AER). The stacked photo diodes are implemented in a 22 × 22 pixel array in a standard STM 90 nm CMOS process. Dynamic range is larger than 60 dB and pixels fill factor is 28%. The pixels employ either simple pulse frequency modulation (PFM) or a Time-to-First-Spike (TFS) mode. A heuristic linear combination of the chip's inherent pseudo colors serves to approximate RGB color representation. Furthermore, the sensor outputs can be processed to represent the radiation in the near infrared (NIR) band without employing external filters, and to color-encode direction of motion due to an asymmetry in the update rates of the different diode layers.

Innate Color Preference of Zebrafish and Its Use in Behavioral Analyses.

Science.gov (United States)

Park, Jong-Su; Ryu, Jae-Ho; Choi, Tae-Ik; Bae, Young-Ki; Lee, Suman; Kang, Hae Jin; Kim, Cheol-Hee

2016-10-01

Although innate color preference of motile organisms may provide clues to behavioral biases, it has remained a longstanding question. In this study, we investigated innate color preference of zebrafish larvae. A cross maze with different color sleeves around each arm was used for the color preference test (R; red, G; green, B; blue, Y; yellow). The findings showed that 5 dpf zebrafish larvae preferred blue over other colors (B > R > G > Y). To study innate color recognition further, tyrosinase mutants were generated using CRISPR/Cas9 system. As a model for oculocutaneous albinism (OCA) and color vision impairment, tyrosinase mutants demonstrated diminished color sensation, indicated mainly by hypopigmentation of the retinal pigment epithelium (RPE). Due to its relative simplicity and ease, color preference screening using zebrafish larvae is suitable for high-throughput screening applications. This system may potentially be applied to the analysis of drug effects on larval behavior or the detection of sensory deficits in neurological disorder models, such as autism-related disorders, using mutant larvae generated by the CRISPR/Cas9 technique.

Visions and visioning in foresight activities

DEFF Research Database (Denmark)

Jørgensen, Michael Søgaard; Grosu, Dan

2007-01-01

The paper discusses the roles of visioning processes and visions in foresight activities and in societal discourses and changes parallel to or following foresight activities. The overall topic can be characterised as the dynamics and mechanisms that make visions and visioning processes work...... or not work. The theoretical part of the paper presents an actor-network theory approach to the analyses of visions and visioning processes, where the shaping of the visions and the visioning and what has made them work or not work is analysed. The empirical part is based on analyses of the roles of visions...... and visioning processes in a number of foresight processes from different societal contexts. The analyses have been carried out as part of the work in the COST A22 network on foresight. A vision is here understood as a description of a desirable or preferable future, compared to a scenario which is understood...

"APOPTOSIS COLOR." SCREENING STRATEGY FOR DIAGNOSIS EARLY STAGES OF PRIMARY OPEN-ANGLE GLAUCOMA

Directory of Open Access Journals (Sweden)

M. A. Kovalevskaya

2017-01-01

Full Text Available Purpose: to develop a screening strategy for the early diagnosis of primary open-angle glaucoma.Patients and Methods: 1 group — 250 patients with suspected glaucoma (42–75 years, 2 — 250 with the 1st stage primary open-angle glaucoma (42–61, 3 — 3,000 healthy persons (35 to 50. Surveys: visometry, tonometry iCare, biomicroscopy, gonioscopy, pachymeria, ophthalmoscopy with a high dioptric lens of 60 D, standard automated perimetry of the SITA-Standard and SITA-SWAP program, assessing the color sensitivity according to the Famsworth-Munsell 100 HueTes method.Results: 1 group — SITA-SWAP: MD -2,55±0,7 dB, PSD 2,46±1,15 dB. Mansell test: TES = 58.6±18.7 (p<0.05, average level of color recognition; mild deficiency of color vision — 41–100 TES; by the RGB system: colors of the first order; tone in RGB (0–239: blue — 160; HCV: blue — 240; range of wavelengths: blue — 440–485 nm; frequency: blue — 620–680 THz. 2 group — on SITA-SWAP: MD — 5,13±1,3 dB, PSD 2,58±0,9 dB. Mansell test: TES = 86,9±21,8; average level of color recognition; mild deficiency of color vision; single deviations in the system of blue (azure, blue, blue; color I order (blue, III order (blue, azure; tone in RGB — (0–239: blue (azure, blue — 140, blue — 160; HCV — blue (azure, blue — 210, blue — 240; range of wavelengths: 450–500 nm (blue — 485–500, blue — 440–485; frequencies: 600–680 THz (blue — 600–620, blue — 620–680. Control group — SITA-SWAP within the norm, Mansell test: TES = 40,1±17,3 (p<0.05, medium level of color recognition, lack of color vision absent / mild, single deviations.Conclusion: in patients with glaucoma suspicion, the score of errors was higher than in the control group with Munsell test. In patients with glaucoma, the number of errors is greater than in patients with suspected glaucoma, and 2.2 times higher than in the control group.

Complementary shifts in photoreceptor spectral tuning unlock the full adaptive potential of ultraviolet vision in birds.

Science.gov (United States)

Toomey, Matthew B; Lind, Olle; Frederiksen, Rikard; Curley, Robert W; Riedl, Ken M; Wilby, David; Schwartz, Steven J; Witt, Christopher C; Harrison, Earl H; Roberts, Nicholas W; Vorobyev, Misha; McGraw, Kevin J; Cornwall, M Carter; Kelber, Almut; Corbo, Joseph C

2016-07-12

Color vision in birds is mediated by four types of cone photoreceptors whose maximal sensitivities (λmax) are evenly spaced across the light spectrum. In the course of avian evolution, the λmax of the most shortwave-sensitive cone, SWS1, has switched between violet (λmax > 400 nm) and ultraviolet (λmax < 380 nm) multiple times. This shift of the SWS1 opsin is accompanied by a corresponding short-wavelength shift in the spectrally adjacent SWS2 cone. Here, we show that SWS2 cone spectral tuning is mediated by modulating the ratio of two apocarotenoids, galloxanthin and 11’,12’-dihydrogalloxanthin, which act as intracellular spectral filters in this cell type. We propose an enzymatic pathway that mediates the differential production of these apocarotenoids in the avian retina, and we use color vision modeling to demonstrate how correlated evolution of spectral tuning is necessary to achieve even sampling of the light spectrum and thereby maintain near-optimal color discrimination.

Multi-sparse dictionary colorization algorithm based on the feature classification and detail enhancement

Science.gov (United States)

Yan, Dan; Bai, Lianfa; Zhang, Yi; Han, Jing

2018-02-01

For the problems of missing details and performance of the colorization based on sparse representation, we propose a conceptual model framework for colorizing gray-scale images, and then a multi-sparse dictionary colorization algorithm based on the feature classification and detail enhancement (CEMDC) is proposed based on this framework. The algorithm can achieve a natural colorized effect for a gray-scale image, and it is consistent with the human vision. First, the algorithm establishes a multi-sparse dictionary classification colorization model. Then, to improve the accuracy rate of the classification, the corresponding local constraint algorithm is proposed. Finally, we propose a detail enhancement based on Laplacian Pyramid, which is effective in solving the problem of missing details and improving the speed of image colorization. In addition, the algorithm not only realizes the colorization of the visual gray-scale image, but also can be applied to the other areas, such as color transfer between color images, colorizing gray fusion images, and infrared images.

Predicting Vision-Related Disability in Glaucoma.

Science.gov (United States)

Abe, Ricardo Y; Diniz-Filho, Alberto; Costa, Vital P; Wu, Zhichao; Medeiros, Felipe A

2018-01-01

To present a new methodology for investigating predictive factors associated with development of vision-related disability in glaucoma. Prospective, observational cohort study. Two hundred thirty-six patients with glaucoma followed up for an average of 4.3±1.5 years. Vision-related disability was assessed by the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) at baseline and at the end of follow-up. A latent transition analysis model was used to categorize NEI VFQ-25 results and to estimate the probability of developing vision-related disability during follow-up. Patients were tested with standard automated perimetry (SAP) at 6-month intervals, and evaluation of rates of visual field change was performed using mean sensitivity (MS) of the integrated binocular visual field. Baseline disease severity, rate of visual field loss, and duration of follow-up were investigated as predictive factors for development of disability during follow-up. The relationship between baseline and rates of visual field deterioration and the probability of vision-related disability developing during follow-up. At baseline, 67 of 236 (28%) glaucoma patients were classified as disabled based on NEI VFQ-25 results, whereas 169 (72%) were classified as nondisabled. Patients classified as nondisabled at baseline had 14.2% probability of disability developing during follow-up. Rates of visual field loss as estimated by integrated binocular MS were almost 4 times faster for those in whom disability developed versus those in whom it did not (-0.78±1.00 dB/year vs. -0.20±0.47 dB/year, respectively; P disability developing over time (odds ratio [OR], 1.34; 95% confidence interval [CI], 1.06-1.70; P = 0.013). In addition, each 0.5-dB/year faster rate of loss of binocular MS during follow-up was associated with a more than 3.5 times increase in the risk of disability developing (OR, 3.58; 95% CI, 1.56-8.23; P = 0.003). A new methodology for classification and analysis

How do we select multiple features? Transient costs for selecting two colors rather than one, persistent costs for color-location conjunctions.

Science.gov (United States)

Lo, Shih-Yu; Holcombe, Alex O

2014-02-01

In a previous study Lo, Howard, & Holcombe (Vision Research 63:20-33, 2012), selecting two colors did not induce a performance cost, relative to selecting one color. For example, requiring possible report of both a green and a red target did not yield a worse performance than when both targets were green. Yet a cost of selecting multiple colors was observed when selection needed be contingent on both color and location. When selecting a red target to the left and a green target to the right, superimposing a green distractor to the left and a red distractor to the right impeded performance. Possibly, participants cannot confine attention to a color at a particular location. As a result, distractors that share the target colors disrupt attentional selection of the targets. The attempt to select the targets must then be repeated, which increases the likelihood that the trial terminates when selection is not effective, even for long trials. Consistent with this, here we find a persistent cost of selecting two colors when the conjunction of color and location is needed, but the cost is confined to short exposure durations when the observer just has to monitor red and green stimuli without the need to use the location information. These results suggest that selecting two colors is time-consuming but effective, whereas selection of simultaneous conjunctions is never entirely successful.

Unilateral Vision Loss after a Dental Visit

Science.gov (United States)

Khattab, Mohammed H.; Wiegand, Annette; Storch, Marcus; Hoerauf, Hans; Feltgen, Nicolas

2018-01-01

Intraoral local anesthetics are widely used for performing painless dental treatments; however, in some cases, they may cause ocular complications such as meiosis, diplopia, nystagmus, ophthalmoplegia, ptosis, and amaurosis. Mostly, the symptoms disappear after several hours; rarely, they have a prolonged character. We describe the case of a 38-year-old young man who had reduced vision in the left eye 5 days after having received intraoral local anesthesia. A diagnosis of cilioretinal artery occlusion with optic disc swelling was made. Ten weeks later, the patient's visual acuity had increased to 20/20, and the swelling of the optic disc had subsided. Although various possible mechanisms for ocular complications after intraoral local anesthetic administration were suggested in the literature, the exact etiology remains unclear. In this case, inadvertent intravascular injection is believed to be the cause. PMID:29681838

Improved Adherence to Vision Self-monitoring with the Vision and Memory Stimulating (VMS) Journal for Non-neovascular Age-related Macular Degeneration during a Randomized Controlled Trial

OpenAIRE

Bittner, Ava K; Torr-Brown, Sheryl; Arnold, Ellen; Nwankwo, Antonia; Beaton, Patricia; Rampat, Radhika; Dagnelie, Gislin; Roser, Mark

2014-01-01

Objective An educational, interactive journal [Vision and Memory Stimulating (VMS) journal] was developed to boost patient confidence and promote long-term adherence with weekly vision self-monitoring in age-related macular degeneration (AMD) patients at risk for vision loss from new-onset neovascularization. Methods In a multicenter randomized controlled trial, 198 subjects with intermediate stage, non-neovascular AMD received the VMS journal or followed usual care (e.g. their doctor’s instr...

Bilateral vision loss due to Leber's hereditary optic neuropathy after long-term alcohol, nicotine and drug abuse.

Science.gov (United States)

Maass, Johanna; Matthé, Egbert

2018-04-01

Leber's hereditary optic neuropathy is relatively rare, and no clinical pathognomonic signs exist. We present a rare case of bilateral vision loss of a patient with multiple drug abuse in the history. A 31-year-old man presented with a history of progressive, decreased vision in both eyes for 6 month. On examination, his visual acuity was hand motion in both eyes. Funduscopy demonstrated a temporal pallor of the optic disc. Goldmann visual field perimetry showed a crescent visual field in the right eye and a circular decrease to less than 50 ° in the left eye. Electroretinogram showed a scotopic b-wave amplitude reduction. Optical coherence tomographies, Heidelberg Retina tomography, visual evoked potentials, and magnetic resonance imaging with contrast as well as blood tests were normal. The patient reported to consume various kinds of drugs as well as recreational drug use and alcohol consumption since he was 16 years old. We started a hemodilution therapy, believing the patient suffered from a bilateral, toxic optic neuropathy due to his lifestyle. Laboratory results later on showed Leber's hereditary optic neuropathy. Leber's hereditary optic neuropathy is a rare disease without a typical, pathognomonic presentation. Even though the patient gave good reasons for a toxic optic neuropathy, one should never stop to test for other diseases.

Prediction of pork loin quality using online computer vision system and artificial intelligence model.

Science.gov (United States)

Sun, Xin; Young, Jennifer; Liu, Jeng-Hung; Newman, David

2018-06-01

The objective of this project was to develop a computer vision system (CVS) for objective measurement of pork loin under industry speed requirement. Color images of pork loin samples were acquired using a CVS. Subjective color and marbling scores were determined according to the National Pork Board standards by a trained evaluator. Instrument color measurement and crude fat percentage were used as control measurements. Image features (18 color features; 1 marbling feature; 88 texture features) were extracted from whole pork loin color images. Artificial intelligence prediction model (support vector machine) was established for pork color and marbling quality grades. The results showed that CVS with support vector machine modeling reached the highest prediction accuracy of 92.5% for measured pork color score and 75.0% for measured pork marbling score. This research shows that the proposed artificial intelligence prediction model with CVS can provide an effective tool for predicting color and marbling in the pork industry at online speeds. Copyright © 2018 Elsevier Ltd. All rights reserved.

Performance evaluation of various classifiers for color prediction of rice paddy plant leaf

Science.gov (United States)

Singh, Amandeep; Singh, Maninder Lal

2016-11-01

The food industry is one of the industries that uses machine vision for a nondestructive quality evaluation of the produce. These quality measuring systems and softwares are precalculated on the basis of various image-processing algorithms which generally use a particular type of classifier. These classifiers play a vital role in making the algorithms so intelligent that it can contribute its best while performing the said quality evaluations by translating the human perception into machine vision and hence machine learning. The crop of interest is rice, and the color of this crop indicates the health status of the plant. An enormous number of classifiers are available to solve the purpose of color prediction, but choosing the best among them is the focus of this paper. Performance of a total of 60 classifiers has been analyzed from the application point of view, and the results have been discussed. The motivation comes from the idea of providing a set of classifiers with excellent performance and implementing them on a single algorithm for the improvement of machine vision learning and, hence, associated applications.

Molecular Basis for Ultraviolet Vision in Invertebrates

OpenAIRE

Salcedo, Ernesto; Zheng, Lijun; Phistry, Meridee; Bagg, Eve E.; Britt, Steven G.

2003-01-01

Invertebrates are sensitive to a broad spectrum of light that ranges from UV to red. Color sensitivity in the UV plays an important role in foraging, navigation, and mate selection in both flying and terrestrial invertebrate animals. Here, we show that a single amino acid polymorphism is responsible for invertebrate UV vision. This residue (UV: lysine vs blue:asparagine or glutamate) corresponds to amino acid position glycine 90 (G90) in bovine rhodopsin, a site affected in autosomal dominant...

How to Make Low Vision "Sexy": A Starting Point for Interdisciplinary Student Recruitment

Science.gov (United States)

Wittich, Walter; Strong, Graham; Renaud, Judith; Southall, Kenneth

2007-01-01

Professionals in the field of low vision are increasingly concerned about the paucity of optometry students who are expressing any interest in low vision as a clinical subspecialty. Concurrent with this apparent disinterest is an increased demand for these services as the baby boomer population becomes more predisposed to age-related vision loss.…

Visual function and ocular status of children with hearing impairment in Oman: A case series

Directory of Open Access Journals (Sweden)

Khandekar Rajiv

2009-01-01

Full Text Available Visual functions of children with hearing disability were evaluated in a school of Muscat, Oman in 2006. Two hundred and twenty-three children were tested for near vision, distant vision, contrast sensitivity, color vision, field of vision, motion perception and crowding. Profound and severe hearing loss was noted in 161 and 63 students respectively. Thirty-five (81% students with refractive error were using spectacles. Color vision and field of vision was defective in one student each. In 286 (64.1% eyes, contrast sensitivity was defective. Abnormal contrast sensitivity was not associated with the severity of hearing loss [RR = 1.04 (95% CI 0.91 to 1.29]. Children with hearing impairment should be assessed for visual functions. Refractive error and defect in contrast sensitivity were unusually high among these children. In addition to visual aids, we recommend environmental changes to improve illumination and contrast to improve the quality of life of such children with double disability.

Sympatric ecological divergence associated with a color polymorphism

OpenAIRE

Kusche, Henrik; Elmer, Kathryn R.; Meyer, Axel

2015-01-01

Background Color polymorphisms are a conspicuous feature of many species and a way to address broad ecological and evolutionary questions. Three potential major evolutionary fates of color polymorphisms are conceivable over time: maintenance, loss, or speciation. However, the understanding of color polymorphisms and their evolutionary implications is frequently impaired by sex-linkage of coloration, unknown inheritance patterns, difficulties in phenotypic characterization, and a lack of evolu...

Polarization imaging enhancement for target vision through haze

Science.gov (United States)

Wu, Hai-Ying; Zhang, San-Xi; Li, Jie; LI, Bin; Tang, Zi-li; Liu, Biao; Jia, Wen-Wu

2016-10-01

Haze, fog, and smoke are turbid medium in the atmosphere which usually degrade viewing condition of outdoor scenes. The resulted images lose contrast and color fidelity with serious degradation. Due to loss of large detailed information of measured scene, it will usually lead to invalid detection and measurement. The suspended particles in the atmosphere and the scene being measured give rise to polarization changes by their reflection. In the process of reflection, absorption and scattering, the object itself can be determined by its own polarization characteristics. Based on this point, we proposed an approach for target vision through haze. This approach is based on the polarization differences between the scene being measured and the scattering background to move the haze effects. It can realize a great visibility enhancement and enable the scene rendering even if imaged under restricted viewing conditions with low polarization. In this work, the detailed theoretical operation principle is presented. A validating imaging system is established and the corresponding experiment is carried out. We present the experimental results of haze-free image of scene with recovered high contrast. This method also can be used to effectively enhance the imaging performance of any other optical system.

Generating Selected Color using RGB, Auxiliary Lights, and Simplex Search

Directory of Open Access Journals (Sweden)

Kim HyungTae

2015-01-01

Full Text Available A mixed light source generates various colors, with the potential to adjust intensities of multiple LEDs, which makes it possible to generate arbitrary colors. Currently, PCs and OSs provide color selection windows that can obtain the RGB or HSL color coordinates of a user’s selection. Mixed light sources are usually composed of LEDs in the primary colors, with LEDs in auxiliary colors such as white and yellow used in a few cases. When using auxiliary color LEDs, the number of LED inputs, the dimming levels, is larger than the number of elements in the color coordinate, which causes an under-determined problem. This study proposed how to determine the dimming levels of LEDs based on the selected color. Commercial LEDs have di_erent optical power values and impure color coordinates, even if they are RGB. Hence, the characteristics of the LEDs were described using a linear model derived from the tri-stimulus values (an XYZ color coordinate model and dimming levels. Color mixing models were derived for the arbitrary number of auxiliary color LEDs. The under-determined problem was solved using a simplex search method without an inverse matrix operation. The proposed method can be applied to a machine vision system and an RGBW light mixer for semiconductor inspection. The dimming levels, obtained using the proposed method were better than derived using other methods.

A Multiple Sensor Machine Vision System for Automatic Hardwood Feature Detection

Science.gov (United States)

D. Earl Kline; Richard W. Conners; Daniel L. Schmoldt; Philip A. Araman; Robert L. Brisbin

1993-01-01

A multiple sensor machine vision prototype is being developed to scan full size hardwood lumber at industrial speeds for automatically detecting features such as knots holes, wane, stain, splits, checks, and color. The prototype integrates a multiple sensor imaging system, a materials handling system, a computer system, and application software. The prototype provides...

The Achromatic ‘Philosophical Zombie', a Syndrome of Cerebral Achromatopsia with Color Anopsognosia

Directory of Open Access Journals (Sweden)

Antonio Carota

2013-04-01

Full Text Available We describe a patient with persistent cerebral achromatopsia occurring after bilateral occipital strokes. Blinded color recognition was assessed with a computerized experimental paradigm and the patient reported the degree of confidence in the response exactness on a visual percent scale. Color recognition was accurate and above chance (Fisher's exact test, p < 0.002. The degree of confidence in the answers showed a significant correlation with recognition scores (Spearman rank order correlation, p < 0.0001. These findings constitute the exceptional condition of what we called color anopsognosia (not knowing of seeing colors and recall the theoretic figure of the ‘philosophical zombie'. However, the cognitive mechanisms of the dissociation between a subjective colorless vision and good performance for color naming still remain poorly understood.

Atomic Color Superfluid via Three-Body Loss

International Nuclear Information System (INIS)

Kantian, A.; Diehl, S.; Zoller, P.; Daley, A. J.; Dalmonte, M.; Hofstetter, W.

2009-01-01

Large three-body loss rates in a three-component Fermi gas confined in an optical lattice can dynamically prevent atoms from tunneling so as to occupy a lattice site with three atoms. This effective constraint not only suppresses the occurrence of actual loss events, but stabilizes BCS-pairing phases by suppressing the formation of trions. We study the effect of the constraint on the many-body physics using bosonization and density matrix renormalization group techniques, and also investigate the full dissipative dynamics including loss for the example of 6 Li.

Evaluation of Synthetic Vision Display Concepts for Improved Awareness in Unusual Attitude Recovery Scenarios

Science.gov (United States)

Nicholas, Stephanie

2016-01-01

A recent study conducted by the Commercial Aviation Safety Team (CAST) determined 40 percent of all fixed-wing fatal accidents, between 2001 and 2011, were caused by Loss-of-Control (LOC) in flight (National Transportation Safety Board, 2015). Based on their findings, CAST recommended manufacturers develop and implement virtual day-visual meteorological conditions (VMC) display systems, such as synthetic vision or equivalent systems (CAST, 2016). In a 2015 simulation study conducted at NASA Langley Research Center (LaRC), researchers gathered to test and evaluate virtual day-VMC displays under realistic flight operation scenarios capable of inducing reduced attention states in pilots. Each display concept was evaluated to determine its efficacy to improve attitude awareness. During the experiment, Evaluation Pilots (EPs) were shown the following three display concepts on the Primary Flight Display (PFD): Baseline, Synthetic Vision (SV) with color gradient, and SV with texture. The baseline configuration was a standard, conventional 'blue over brown' display. Experiment scenarios were simulated over water to evaluate Unusual Attitude (UA) recovery over 'featureless terrain' environments. Thus, the SV with color gradient configuration presented a 'blue over blue' display with a linear blue color progression, to differentiate attitude changes between sky and ocean. The SV with texture configuration presented a 'blue over blue' display with a black checkerboard texture atop a synthetic ocean. These displays were paired with a Background Attitude Indicator (BAI) concept. The BAI was presented across all four Head-Down Displays (HDDs), displaying a wide field-of-view blue-over-blue attitude indicator. The BAI aligned with the PFD and showed through the background of the navigation displays with opaque transparency. Each EP participated in a two-part experiment series with a total seventy-five trial runs: Part I included a set of twenty-five Unusual Attitude Recovery (UAR

Origins of strabismus and loss of binocular vision

Science.gov (United States)

Bui Quoc, Emmanuel; Milleret, Chantal

2014-01-01

Strabismus is a frequent ocular disorder that develops early in life in humans. As a general rule, it is characterized by a misalignment of the visual axes which most often appears during the critical period of visual development. However other characteristics of strabismus may vary greatly among subjects, for example, being convergent or divergent, horizontal or vertical, with variable angles of deviation. Binocular vision may also vary greatly. Our main goal here is to develop the idea that such “polymorphy” reflects a wide variety in the possible origins of strabismus. We propose that strabismus must be considered as possibly resulting from abnormal genetic and/or acquired factors, anatomical and/or functional abnormalities, in the sensory and/or the motor systems, both peripherally and/or in the brain itself. We shall particularly develop the possible “central” origins of strabismus. Indeed, we are convinced that it is time now to open this “black box” in order to move forward. All of this will be developed on the basis of both presently available data in literature (including most recent data) and our own experience. Both data in biology and medicine will be referred to. Our conclusions will hopefully help ophthalmologists to better understand strabismus and to develop new therapeutic strategies in the future. Presently, physicians eliminate or limit the negative effects of such pathology both on the development of the visual system and visual perception through the use of optical correction and, in some cases, extraocular muscle surgery. To better circumscribe the problem of the origins of strabismus, including at a cerebral level, may improve its management, in particular with respect to binocular vision, through innovating tools by treating the pathology at the source. PMID:25309358

[A study of biomechanical method for urine test based on color difference estimation].

Science.gov (United States)

Wang, Chunhong; Zhou, Yue; Zhao, Hongxia; Zhou, Fengkun

2008-02-01

The biochemical analysis of urine is an important inspection and diagnosis method in hospitals. The conventional method of urine analysis covers mainly colorimetric visual appraisement and automation detection, in which the colorimetric visual appraisement technique has been superseded basically, and the automation detection method is adopted in hospital; moreover, the price of urine biochemical analyzer on market is around twenty thousand RMB yuan (Y), which is hard to enter into ordinary families. It is known that computer vision system is not subject to the physiological and psychological influence of person, its appraisement standard is objective and steady. Therefore, according to the color theory, we have established a computer vision system, which can carry through collection, management, display, and appraisement of color difference between the color of standard threshold value and the color of urine test paper after reaction with urine liquid, and then the level of an illness can be judged accurately. In this paper, we introduce the Urine Test Biochemical Analysis method, which is new and can be popularized in families. Experimental result shows that this test method is easy-to-use and cost-effective. It can realize the monitoring of a whole course and can find extensive applications.

Characteristics and New Measurement Method of NCSFs of Individual Color Mechanisms of Human Vision

International Nuclear Information System (INIS)

Jing-Jing, Ge; Zhao-Qi, Wang; Yan, Wang; Kan-Xing, Zhao

2010-01-01

We propose a new method for determining neural contrast sensitivity functions (NCSFs) of isolated color mechanisms based on the measurements of wave-front aberrations and isoluminant color contrast sensitivity functions (CSFs). Compared with the traditional method, this technique avoids the coherent noise and speckle noise, which are brought by the interference of laser beams, and has great flexibility for the measurements of NCSF of different color mechanisms. Our experiments indicate that the mean NCSF and CSF of the red mechanism are higher than those of the green mechanism, respectively, while those of the blue mechanism are the lowest. However the relative heights of the peak of NCSF and CSF between red and green mechanisms vary in subjects. There are some individuals whose peak values of NCSF and/or CSF of green mechanism are higher than that of the red mechanism. The NCSFs and CSFs of isolated color mechanisms all exhibit the similar characteristics and variation tendency. With the statistical average, the NCSFs of the red, green and blue mechanisms are higher than the corresponding CSFs in the whole spatial frequency. Compared with the corresponding CSFs curves, the peaks of the NCSFs of isolated color mechanisms shift toward higher spatial frequencies, especially for that of blue mechanism which has a largest shift of 3.9c/deg

The impact of low vision on activities of daily living, symptoms of depression, feelings of anxiety and social support in community-living older adults seeking vision rehabilitation services

NARCIS (Netherlands)

Kempen, Gertrudis I. J. M.; Ballemans, Judith; Ranchor, Adelita V.; van Rens, Ger H. M. B.; Zijlstra, G. A. Rixt

2012-01-01

Purpose Previous studies showed that older persons with vision loss generally reported low levels of health-related quality of life, although study outcomes with respect to feelings of anxiety and social support were inconsistent. The objective of this study was to examine the impact of low vision

The impact of low vision on activities of daily living, symptoms of depression, feelings of anxiety and social support in community-living older adults seeking vision rehabilitation services

NARCIS (Netherlands)

Kempen, G.I.J.M.; Ballemans, J.; Ranchor, A.V.; van Rens, G.H.M.B.; Zijlstra, G.A.R.

2012-01-01

Purpose: Previous studies showed that older persons with vision loss generally reported low levels of health-related quality of life, although study outcomes with respect to feelings of anxiety and social support were inconsistent. The objective of this study was to examine the impact of low vision

Single Lens Dual-Aperture 3D Imaging System: Color Modeling

Science.gov (United States)

Bae, Sam Y.; Korniski, Ronald; Ream, Allen; Fritz, Eric; Shearn, Michael

2012-01-01

In an effort to miniaturize a 3D imaging system, we created two viewpoints in a single objective lens camera. This was accomplished by placing a pair of Complementary Multi-band Bandpass Filters (CMBFs) in the aperture area. Two key characteristics about the CMBFs are that the passbands are staggered so only one viewpoint is opened at a time when a light band matched to that passband is illuminated, and the passbands are positioned throughout the visible spectrum, so each viewpoint can render color by taking RGB spectral images. Each viewpoint takes a different spectral image from the other viewpoint hence yielding a different color image relative to the other. This color mismatch in the two viewpoints could lead to color rivalry, where the human vision system fails to resolve two different colors. The difference will be closer if the number of passbands in a CMBF increases. (However, the number of passbands is constrained by cost and fabrication technique.) In this paper, simulation predicting the color mismatch is reported.

Some examples of image warping for low vision prosthesis

Science.gov (United States)

Juday, Richard D.; Loshin, David S.

1988-01-01

NASA has developed an image processor, the Programmable Remapper, for certain functions in machine vision. The Remapper performs a highly arbitrary geometric warping of an image at video rate. It might ultimately be shrunk to a size and cost that could allow its use in a low-vision prosthesis. Coordinate warpings have been developed for retinitis pigmentosa (tunnel vision) and for maculapathy (loss of central field) that are intended to make best use of the patient's remaining viable retina. The rationales and mathematics are presented for some warpings that we will try in clinical studies using the Remapper's prototype.

Hyperspectral image reconstruction using RGB color for foodborne pathogen detection on agar plates

Science.gov (United States)

Yoon, Seung-Chul; Shin, Tae-Sung; Park, Bosoon; Lawrence, Kurt C.; Heitschmidt, Gerald W.

2014-03-01

This paper reports the latest development of a color vision technique for detecting colonies of foodborne pathogens grown on agar plates with a hyperspectral image classification model that was developed using full hyperspectral data. The hyperspectral classification model depended on reflectance spectra measured in the visible and near-infrared spectral range from 400 and 1,000 nm (473 narrow spectral bands). Multivariate regression methods were used to estimate and predict hyperspectral data from RGB color values. The six representative non-O157 Shiga-toxin producing Eschetichia coli (STEC) serogroups (O26, O45, O103, O111, O121, and O145) were grown on Rainbow agar plates. A line-scan pushbroom hyperspectral image sensor was used to scan 36 agar plates grown with pure STEC colonies at each plate. The 36 hyperspectral images of the agar plates were divided in half to create training and test sets. The mean Rsquared value for hyperspectral image estimation was about 0.98 in the spectral range between 400 and 700 nm for linear, quadratic and cubic polynomial regression models and the detection accuracy of the hyperspectral image classification model with the principal component analysis and k-nearest neighbors for the test set was up to 92% (99% with the original hyperspectral images). Thus, the results of the study suggested that color-based detection may be viable as a multispectral imaging solution without much loss of prediction accuracy compared to hyperspectral imaging.

How To Control Color Appearance With Instrumentation

Science.gov (United States)

Burns, Margaret E.

1980-05-01

Colorimetry, as defined by the International Commission on Illumination, is the measurement of colors, made possible by the properties of the eye and based on a set of conventions. Instrumentation for measuring object color, therefore, must be based on a human observer. The intent is to design an instrument that in effect responds as a person would, so that research development, production control and quality control areas have some means of assessing the acceptability of the appearance of a product. Investigations of a human observer's psychological response to color, and the manner in which visual observations are made, give the instrument designer and manufacturer data necessary to answer two questions: a. How can we put numbers (instrument read-out) on a perception that occurs in the brain of the observer? b. What can we learn from examination of a visual observing situation that will guide us in our design of an instrumental simulation of this situation? Involving as it does our own daily, almost unconscious, practice of making judgments concerning the things we see, the design and manufacture of color measurement instruments is an exceedingly interesting field. The advances being made concurrently today in research concerning human color vision and in optical and electronic technology will make possible increasingly useful instrumentation for quality control of product color.

Color encoding in biologically-inspired convolutional neural networks.

Science.gov (United States)

Rafegas, Ivet; Vanrell, Maria

2018-05-11

Convolutional Neural Networks have been proposed as suitable frameworks to model biological vision. Some of these artificial networks showed representational properties that rival primate performances in object recognition. In this paper we explore how color is encoded in a trained artificial network. It is performed by estimating a color selectivity index for each neuron, which allows us to describe the neuron activity to a color input stimuli. The index allows us to classify whether they are color selective or not and if they are of a single or double color. We have determined that all five convolutional layers of the network have a large number of color selective neurons. Color opponency clearly emerges in the first layer, presenting 4 main axes (Black-White, Red-Cyan, Blue-Yellow and Magenta-Green), but this is reduced and rotated as we go deeper into the network. In layer 2 we find a denser hue sampling of color neurons and opponency is reduced almost to one new main axis, the Bluish-Orangish coinciding with the dataset bias. In layers 3, 4 and 5 color neurons are similar amongst themselves, presenting different type of neurons that detect specific colored objects (e.g., orangish faces), specific surrounds (e.g., blue sky) or specific colored or contrasted object-surround configurations (e.g. blue blob in a green surround). Overall, our work concludes that color and shape representation are successively entangled through all the layers of the studied network, revealing certain parallelisms with the reported evidences in primate brains that can provide useful insight into intermediate hierarchical spatio-chromatic representations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Development of a body motion interactive system with a weight voting mechanism and computer vision technology

Science.gov (United States)

Lin, Chern-Sheng; Chen, Chia-Tse; Shei, Hung-Jung; Lay, Yun-Long; Chiu, Chuang-Chien

2012-09-01

This study develops a body motion interactive system with computer vision technology. This application combines interactive games, art performing, and exercise training system. Multiple image processing and computer vision technologies are used in this study. The system can calculate the characteristics of an object color, and then perform color segmentation. When there is a wrong action judgment, the system will avoid the error with a weight voting mechanism, which can set the condition score and weight value for the action judgment, and choose the best action judgment from the weight voting mechanism. Finally, this study estimated the reliability of the system in order to make improvements. The results showed that, this method has good effect on accuracy and stability during operations of the human-machine interface of the sports training system.

A MULTI-STAGE COLOR MODEL REVISITED: IMPLICATIONS FOR A GENE THERAPY CURE FOR RED-GREEN COLORBLINDNESS

OpenAIRE

Mancuso, Katherine; Mauck, Matthew C.; Kuchenbecker, James A.; Neitz, Maureen; Neitz, Jay

2010-01-01

In 1993, DeValois and DeValois proposed a “multi-stage color model” to explain how the cortex is ultimately able to deconfound the responses of neurons receiving input from three cone types in order to produce separate red-green and blue-yellow systems, as well as segregate luminance percepts (black-white) from color. This model extended the biological implementation of Hurvich and Jameson’s Opponent-Process Theory of color vision, a two-stage model encompassing the three cone types combined ...

[Vision test program for ophthalmologists on Apple II, IIe and IIc computers].

Science.gov (United States)

Huber, C

1985-03-01

A microcomputer program for the Apple II family of computers on a monochrome and a color screen is described. The program draws most of the tests used by ophthalmologists, and is offered as an alternative to a projector system. One advantage of the electronic generation of drawings is that true random orientation of Pflueger's E is possible. Tests are included for visual acuity (Pflueger's E, Landolt rings, numbers and children's drawings). Colored tests include a duochrome test, simple color vision tests, a fixation help with a musical background, a cobalt blue test and a Worth figure. In the astigmatic dial a mobile pointer helps to determine the axis. New tests can be programmed by the user and exchanged on disks among collageues.

Colors Identification for Blind People using Cell Phone

International Nuclear Information System (INIS)

Dominguez, A L; Graffigna, J P

2011-01-01

Assistive Technology (AT) is an interdisciplinary research area that allows finding solutions to the individual with disability by easing or improving the functions or the skills for accomplishing daily activities. A technology can be considered 'assistive' if it is fit for the needs, skills and capabilities of the person, taking into account mainly the intended activity and the limitations of the context and environs where the person performs such activity. The current work intends to solve the problems of vision impaired persons to recognize colors. To this aim, a Java application for cell phones has been made which lets complement the mobiles' technology with that of image processing. The means to obtain the colors from a view are based on analysing the different color models join to a mechanism to reduce the collected data. This paper describes preliminary experiences, methodology and results considering the user perception.

Colors Identification for Blind People using Cell Phone

Science.gov (United States)

Dominguez, A. L.; Graffigna, J. P.

2011-12-01

Assistive Technology (AT) is an interdisciplinary research area that allows finding solutions to the individual with disability [1] by easing or improving the functions or the skills for accomplishing daily activities. A technology can be considered "assistive" if it is fit for the needs, skills and capabilities of the person, taking into account mainly the intended activity and the limitations of the context and environs where the person performs such activity. The current work intends to solve the problems of vision impaired persons to recognize colors. To this aim, a Java application for cell phones has been made which lets complement the mobiles' technology with that of image processing. The means to obtain the colors from a view are based on analysing the different color models join to a mechanism to reduce the collected data. This paper describes preliminary experiences, methodology and results considering the user perception.

The fossil record, function, and possible origins of shell color patterns in Paleozoic marine invertebrates

Energy Technology Data Exchange (ETDEWEB)

Kobluk, D.R. (Univ. of Toronto, Ontario (Canada)); Mapes, R.H. (Ohio Univ., Athens (USA))

1989-02-01

Fossil invertebrate shells and carapaces displaying preserved original color patterns are among the rarest fossils. The fossil record of color patterns extends into the Middle Cambrian where the trilobite Anomocare displays a fan-like array of stripes on the pygidium. About 180 Paleozic genera are known with patterns, including trilobites, cephalopods, gastropods, brachiopods, bivalves, crinoids, and crustaceans. Based upon an analysis of these taxa, it appears that patterns and pigments in middle and late Paleozoic invertebrates may have served several functions such as warning displays, light screening, camouflage, or waste disposal. However, the presence of color patterns in fossil invertebrates in the early Paleozoic may have developed prior to the evolution of vision sufficiently sophisticated to see them. This suggests that camouflage and warning displays were not the original functions of color patterns, and that in the earliest Paleozoic they may not have been functional. The authors propose a hypothesis that involves three developmental phases in the evolution of invertebrate color patterns: (1) the incorporation of metabolic by-products, perhaps some pigmented and some not pigmented, into shells and carapaces as a means of disposal of dietary or metabolic wastes, (2) use of these pigments and patterns as an environmental adaptation, such as light screening, and (3) display during and following the evolution of vision in predators sufficiently sophisticated to see the patterns.

Functional changes at the preferred retinal locus in subjects with bilateral central vision loss.

Science.gov (United States)

Krishnan, Arun Kumar; Bedell, Harold E

2018-01-01

Subjects with bilateral central vision loss (CVL) use a retinal region called the preferred retinal locus (PRL) for performing various visual tasks. We probed the fixation PRL in individuals with bilateral macular disease, including age-related macular degeneration (AMD) and Stargardt disease (STGD), for localized sensitivity deficits. Three letter words at the critical print size were presented in the NIDEK MP-1 microperimeter to determine the fixation PRL and its radial retinal eccentricity from the residual fovea in 29 subjects with bilateral CVL. Fixation stability was defined as the median bivariate contour ellipse area (BCEA) from 3 fixation assessments. A standard 10-2 grid (68 locations, 2° apart) was used to determine central retinal sensitivity for Goldmann size II test spots. Baseline and follow-up supra-threshold screening of the fixation PRL for localized sensitivity deficits was performed using high density (0.2° or 0.3° apart) 0 dB Goldmann size II test spots. Custom MATLAB code and a dual bootstrapping algorithm were used to register test-spot locations from the baseline and follow-up tests. Locations where the 0 dB test spots were not seen on either test were labeled as micro-scotomas (MSs). Median BCEA correlated poorly with the radial eccentricity of the fixation PRL. Mean (±SD) sensitivity around the PRL from 10-2 testing was 4.93 ± 4.73 dB. The average percentage of MSs was similar for patients with AMD (25.4%), STGD (20.3%), and other etiologies of CVL (27.1%). The fixation PRL in subjects with bilateral CVL frequently includes local regions of sensitivity loss.