Identifying multiple influential spreaders in term of the distance-based coloring

Energy Technology Data Exchange (ETDEWEB)

Guo, Lei; Lin, Jian-Hong; Guo, Qiang [Research Center of Complex Systems Science, University of Shanghai for Science and Technology, Shanghai 200093 (China); Liu, Jian-Guo, E-mail: liujg004@ustc.edu.cn [Research Center of Complex Systems Science, University of Shanghai for Science and Technology, Shanghai 200093 (China); Data Science and Cloud Service Research Centre, Shanghai University of Finance and Economics, Shanghai 200433 (China)

2016-02-22

Identifying influential nodes is of significance for understanding the dynamics of information diffusion process in complex networks. In this paper, we present an improved distance-based coloring method to identify the multiple influential spreaders. In our method, each node is colored by a kind of color with the rule that the distance between initial nodes is close to the average distance of a network. When all nodes are colored, nodes with the same color are sorted into an independent set. Then we choose the nodes at the top positions of the ranking list according to their centralities. The experimental results for an artificial network and three empirical networks show that, comparing with the performance of traditional coloring method, the improvement ratio of our distance-based coloring method could reach 12.82%, 8.16%, 4.45%, 2.93% for the ER, Erdős, Polblogs and Routers networks respectively. - Highlights: • We present an improved distance-based coloring method to identify the multiple influential spreaders. • Each node is colored by a kind of color where the distance between initial nodes is close to the average distance. • For three empirical networks show that the improvement ratio of our distance-based coloring method could reach 8.16% for the Erdos network.

Identifying multiple influential spreaders in term of the distance-based coloring

International Nuclear Information System (INIS)

Guo, Lei; Lin, Jian-Hong; Guo, Qiang; Liu, Jian-Guo

2016-01-01

Identifying influential nodes is of significance for understanding the dynamics of information diffusion process in complex networks. In this paper, we present an improved distance-based coloring method to identify the multiple influential spreaders. In our method, each node is colored by a kind of color with the rule that the distance between initial nodes is close to the average distance of a network. When all nodes are colored, nodes with the same color are sorted into an independent set. Then we choose the nodes at the top positions of the ranking list according to their centralities. The experimental results for an artificial network and three empirical networks show that, comparing with the performance of traditional coloring method, the improvement ratio of our distance-based coloring method could reach 12.82%, 8.16%, 4.45%, 2.93% for the ER, Erdős, Polblogs and Routers networks respectively. - Highlights: • We present an improved distance-based coloring method to identify the multiple influential spreaders. • Each node is colored by a kind of color where the distance between initial nodes is close to the average distance. • For three empirical networks show that the improvement ratio of our distance-based coloring method could reach 8.16% for the Erdos network.

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

Science.gov (United States)

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.

Colored Contact Lens Dangers

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Full Text Available ... use of colored contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses ... away without suffering an eye injury. However, the natural protective mechanisms of the eye – such as the ...

Do focal colors look particularly "colorful"?

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Witzel, Christoph; Franklin, Anna

2014-04-01

If the most typical red, yellow, green, and blue were particularly colorful (i.e., saturated), they would "jump out to the eye." This would explain why even fundamentally different languages have distinct color terms for these focal colors, and why unique hues play a prominent role in subjective color appearance. In this study, the subjective saturation of 10 colors around each of these focal colors was measured through a pairwise matching task. Results show that subjective saturation changes systematically across hues in a way that is strongly correlated to the visual gamut, and exponentially related to sensitivity but not to focal colors.

Eye Cosmetic Safety

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... you're wearing? In the United States, the use of color additives is strictly regulated. A number of color ... to color additives that are not approved for use in the area of the eye. Avoid color additives that are not approved for use in ...

Colored Contact Lens Dangers

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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 ...

IRAS colors of VLA identified objects in the galaxy

International Nuclear Information System (INIS)

Fich, M.; Terebey, S.

1987-01-01

Infrared Astronomy Satellite (IRAS) sources found within 4 degrees of l = 125 deg, b = 2 deg on the 3rd HCON 60 micron Sky Brightness Images were observed at the Very Large Array (VLA). Regions were to be identified where massive stars are forming by looking for small areas of radio continuum emissions. The IRAS sources could be divided into three groups by their IRAS 12 micron/25 micron and 60 micron/100 micron color. The group identified with star forming regions contained essentially all of the objects with extended radio emission. In all of these cases the extended radio emission showed a morphology consistent with the identification of these objects as HII regions. The conclusion drawn is that star formation regions can be distinguished from other objects by their infrared colors

Colored Contact Lens Dangers

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Full Text Available ... colored contact lenses to enhance their costumes. From blood-drenched vampire eyes to glow-in-the-dark ... properly fitted may scratch the eye or cause blood vessels to grow into the cornea. Even if ...

Colored Contact Lens Dangers

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Full Text Available ... Cleveland. "This is far from the truth." Real People, Real Problems with Colored Contact Lenses Julian: Teenager ... about the members of the eye-care team . Consumer warning about the improper use of colored contact ...

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 ...

Cognitive aspects of color

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Derefeldt, Gunilla A. M.; Menu, Jean-Pierre; Swartling, Tiina

1995-04-01

This report surveys cognitive aspects of color in terms of behavioral, neuropsychological, and neurophysiological data. Color is usually defined as psychophysical color or as perceived color. Behavioral data on categorical color perception, absolute judgement of colors, color coding, visual search, and visual awareness refer to the more cognitive aspects of color. These are of major importance in visual synthesis and spatial organization, as already shown by the Gestalt psychologists. Neuropsychological and neurophysiological findings provide evidence for an interrelation between cognitive color and spatial organization. Color also enhances planning strategies, as has been shown by studies on color and eye movements. Memory colors and the color- language connections in the brain also belong among the cognitive aspects of color.

Colored Contact Lens Dangers

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Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... new application of artificial intelligence shows whether a patient’s eyes point to high blood pressure or risk ...

Retinal vascular caliber, iris color, and age-related macular degeneration in the Irish Nun Eye Study.

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McGowan, Amy; Silvestri, Giuliana; Moore, Evelyn; Silvestri, Vittorio; Patterson, Christopher C; Maxwell, Alexander P; McKay, Gareth J

2014-12-18

To evaluate the relationship between retinal vascular caliber (RVC), iris color, and age-related macular degeneration (AMD) in elderly Irish nuns. Data from 1233 participants in the cross-sectional observational Irish Nun Eye Study were assessed from digital photographs with a standardized protocol using computer-assisted software. Macular images were graded according to the modified Wisconsin Age-related Maculopathy Grading System. Regression models were used to assess associations, adjusting for age, mean arterial blood pressure, body mass index, refraction, and fellow RVC. In total, 1122 (91%) participants had gradable retinal images of sufficient quality for vessel assessment (mean age: 76.3 years [range, 56-100 years]). In an unadjusted analysis, we found some support for a previous finding that individuals with blue iris color had narrower retinal venules compared to those with brown iris color (P < 0.05), but this was no longer significant after adjustment. Age-related macular degeneration status was categorized as no AMD, any AMD, and late AMD only. Individuals with any AMD (early or late AMD) had significantly narrower arterioles and venules compared to those with no AMD in an unadjusted analysis, but this was no longer significant after adjustment. A nonsignificant reduced risk of any AMD or late AMD only was observed in association with brown compared to blue iris color, in both unadjusted and adjusted analyses. Retinal vascular caliber was not significantly associated with iris color or early/late AMD after adjustment for confounders. A lower but nonsignificant AMD risk was observed in those with brown compared to blue iris color. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

Does correlated color temperature affect the ability of humans to identify veins?

DEFF Research Database (Denmark)

Argyraki, Aikaterini; Clemmensen, Line Katrine Harder; Petersen, Paul Michael

2016-01-01

In the present study we provide empirical evidence and demonstrate statistically that white illumination settings can affect the human ability to identify veins in the inner hand vasculature. A special light-emitting diode lamp with high color rendering index (CRI 84–95) was developed and the eff......In the present study we provide empirical evidence and demonstrate statistically that white illumination settings can affect the human ability to identify veins in the inner hand vasculature. A special light-emitting diode lamp with high color rendering index (CRI 84–95) was developed...... and the effect of correlated color temperature was evaluated, in the range between 2600 and 5700 K at an illuminance of 40 9 lx on the ability of adult humans to identify veins. It is shown that the ability to identify veins can, on average, be increased up to 24% when white illumination settings that do...... not resemble incandescent light are applied. The illuminance reported together with the effect of white illumination settings on direct visual perception of biosamples are relevant for clinical investigations during the night. © 2015 Optical Society of America...

ASSOCIATION BETWEEN VISUAL FUNCTION AND SUBRETINAL DRUSENOID DEPOSITS IN NORMAL AND EARLY AGE-RELATED MACULAR DEGENERATION EYES.

Science.gov (United States)

Neely, David; Zarubina, Anna V; Clark, Mark E; Huisingh, Carrie E; Jackson, Gregory R; Zhang, Yuhua; McGwin, Gerald; Curcio, Christine A; Owsley, Cynthia

2017-07-01

To examine the association between subretinal drusenoid deposits (SDDs) identified by multimodal retinal imaging and visual function in older eyes with normal macular health or in the earliest phases of age-related macular degeneration (AMD). Age-related macular degeneration status for each eye was defined according to the Age-Related Eye Disease Study (AREDS) 9-step classification system (normal = Step 1, early AMD = Steps 2-4) based on color fundus photographs. Visual functions measured were best-corrected photopic visual acuity, contrast and light sensitivity, mesopic visual acuity, low-luminance deficit, and rod-mediated dark adaptation. Subretinal drusenoid deposits were identified through multimodal imaging (color fundus photographs, infrared reflectance and fundus autofluorescence images, and spectral domain optical coherence tomography). The sample included 1,202 eyes (958 eyes with normal health and 244 eyes with early AMD). In normal eyes, SDDs were not associated with any visual function evaluated. In eyes with early AMD, dark adaptation was markedly delayed in eyes with SDDs versus no SDD (a 4-minute delay on average), P = 0.0213. However, this association diminished after age adjustment, P = 0.2645. Other visual functions in early AMD eyes were not associated with SDDs. In a study specifically focused on eyes in normal macular health and in the earliest phases of AMD, early AMD eyes with SDDs have slower dark adaptation, largely attributable to the older ages of eyes with SDD; they did not exhibit deficits in other visual functions. Subretinal drusenoid deposits in older eyes in normal macular health are not associated with any visual functions evaluated.

Color impact in visual attention deployment considering emotional images

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Chamaret, C.

2012-03-01

Color is a predominant factor in the human visual attention system. Even if it cannot be sufficient to the global or complete understanding of a scene, it may impact the visual attention deployment. We propose to study the color impact as well as the emotion aspect of pictures regarding the visual attention deployment. An eye-tracking campaign has been conducted involving twenty people watching half pictures of database in full color and the other half of database in grey color. The eye fixations of color and black and white images were highly correlated leading to the question of the integration of such cues in the design of visual attention model. Indeed, the prediction of two state-of-the-art computational models shows similar results for the two color categories. Similarly, the study of saccade amplitude and fixation duration versus time viewing did not bring any significant differences between the two mentioned categories. In addition, spatial coordinates of eye fixations reveal an interesting indicator for investigating the differences of visual attention deployment over time and fixation number. The second factor related to emotion categories shows evidences of emotional inter-categories differences between color and grey eye fixations for passive and positive emotion. The particular aspect associated to this category induces a specific behavior, rather based on high frequencies, where the color components influence the visual attention deployment.

A color-communication scheme for digital imagery

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Acosta, Alex

1987-01-01

Color pictures generated from digital images are frequently used by geologists, foresters, range managers, and others. These color products are preferred over black and white pictures because the human eye is more sensitive to color differences than to various shades of gray. Color discrimination is a function of perception, and therefore colors in these color composites are generally described subjectively, which can lead to ambiguous color communication. Numerous color-coordinate systems are available that quantitively relate digital triplets representing amounts of red, free, and blue to the parameters of hue, saturation, and intensity perceived by the eye. Most of these systems implement a complex transformation of the primary colors to a color space that is hard to visualize, thus making it difficult to relate digital triplets to perception parameters. This paper presents a color-communcation scheme that relates colors on a color triangle to corresponding values of "hue" (H), "saturation" (S), and chromaticity coordinates (x,y,z). The scheme simplifies the relation between red, green, and blue (RGB) digital triplets and the color generated by these triplets. Some examples of the use of the color-communication scheme in digital image processing are presented.

Evaluating the accuracy of tooth color measurement by combining the Munsell color system and dental colorimeter.

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Chang, Jiun-Yao; Chen, Wen-Cheng; Huang, Ta-Ko; Wang, Jen-Chyan; Fu, Po-Sung; Chen, Jeng-Huey; Hung, Chun-Cheng

2012-09-01

As we pay increasing attention to dental aesthetics, tooth color matching has become an important part of daily dental practice. This aim of this study was to develop a method to enhance the accuracy of a tooth color matching machine. The Munsell color tabs in the range of natural human teeth were measured using a tooth color measuring machine (ShadeEye NCC). The machine's accuracy was analyzed using an analysis of variance test and a Tukey post-hoc test. When matching the Munsell color tabs with the ShadeEye NCC colorimeter, settings of Chroma greater than 6 and Value less than 4 showed unacceptable clinical results. When the CIELAB mode was used, the a* value (which represents the red-green axis in the Commission Internationale de l'Eclairage color space) made no significant difference (p=0.84), the L* value (which represents the lightness) resulted in a negative correlation, and the b* value (which represents the yellow-blue axis) resulted in a positive correlation with ΔE. When the Munsell color tabs and the Vitapan were measured in the same mode and compared, the inaccuracies showed that the Vitapan was not a proper tool for evaluating the stability and accuracy of ShadeEye NCC. By knowing the limitations of the machine, we evaluated the data using the Munsell color tabs; shade beyond the acceptable range should be reevaluated using a visual shade matching method, or if measured by another machine, this shade range should be covered to obtain more accurate results. Copyright © 2012. Published by Elsevier B.V.

Identifying and assessing strategies for evaluating the impact of mobile eye health units on health outcomes.

Science.gov (United States)

Fu, Shiwan; Turner, Angus; Tan, Irene; Muir, Josephine

2017-12-01

To identify and assess strategies for evaluating the impact of mobile eye health units on health outcomes. Systematic literature review. Worldwide. Peer-reviewed journal articles that included the use of a mobile eye health unit. Journal articles were included if outcome measures reflected an assessment of the impact of a mobile eye health unit on health outcomes. Six studies were identified with mobile services offering diabetic retinopathy screening (three studies), optometric services (two studies) and orthoptic services (one study). This review identified and assessed strategies in existing literature used to evaluate the impact of mobile eye health units on health outcomes. Studies included in this review used patient outcomes (i.e. disease detection, vision impairment, treatment compliance) and/or service delivery outcomes (i.e. cost per attendance, hospital transport use, inappropriate referrals, time from diabetic retinopathy photography to treatment) to evaluate the impact of mobile eye health units. Limitations include difficulty proving causation of specific outcome measures and the overall shortage of impact evaluation studies. Variation in geographical location, service population and nature of eye care providers limits broad application. © 2017 National Rural Health Alliance Inc.

RNAi-Mediated Reverse Genetic Screen Identified Drosophila Chaperones Regulating Eye and Neuromuscular Junction Morphology

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Sandeep Raut

2017-07-01

Full Text Available Accumulation of toxic proteins in neurons has been linked with the onset of neurodegenerative diseases, which in many cases are characterized by altered neuronal function and synapse loss. Molecular chaperones help protein folding and the resolubilization of unfolded proteins, thereby reducing the protein aggregation stress. While most of the chaperones are expressed in neurons, their functional relevance remains largely unknown. Here, using bioinformatics analysis, we identified 95 Drosophila chaperones and classified them into seven different classes. Ubiquitous actin5C-Gal4-mediated RNAi knockdown revealed that ∼50% of the chaperones are essential in Drosophila. Knocking down these genes in eyes revealed that ∼30% of the essential chaperones are crucial for eye development. Using neuron-specific knockdown, immunocytochemistry, and robust behavioral assays, we identified a new set of chaperones that play critical roles in the regulation of Drosophila NMJ structural organization. Together, our data present the first classification and comprehensive analysis of Drosophila chaperones. Our screen identified a new set of chaperones that regulate eye and NMJ morphogenesis. The outcome of the screen reported here provides a useful resource for further elucidating the role of individual chaperones in Drosophila eye morphogenesis and synaptic development.

Colored Contact Lens Dangers

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Full Text Available ... eye-care team . Consumer warning about the improper use of colored contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses you are considering buying approved by the FDA? Check the FDA's database of approved contact lenses . Related Stories Prevent Infection ...

Testing Children for Color Blindness

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... Stories Español Eye Health / News Testing Children for Color Blindness Leer en Español: Pruebas para Detectar Daltonismo en ... study shows that kids can be tested for color blindness as soon as age 4, finds Caucasian boys ...

What It's Like to Be Color Blind

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... a green leaf might look tan or gray. Color Blindness Is Passed Down Color blindness is almost always an inherited (say: in-HER- ... Eye doctors (and some school nurses) test for color blindness by showing a picture made up of different ...

Comparison of eye imaging pattern recognition using neural network

Science.gov (United States)

Bukhari, W. M.; Syed A., M.; Nasir, M. N. M.; Sulaima, M. F.; Yahaya, M. S.

2015-05-01

The beauty of eye recognition system that it is used in automatic identifying and verifies a human weather from digital images or video source. There are various behaviors of the eye such as the color of the iris, size of pupil and shape of the eye. This study represents the analysis, design and implementation of a system for recognition of eye imaging. All the eye images that had been captured from the webcam in RGB format must through several techniques before it can be input for the pattern and recognition processes. The result shows that the final value of weight and bias after complete training 6 eye images for one subject is memorized by the neural network system and be the reference value of the weight and bias for the testing part. The target classifies to 5 different types for 5 subjects. The eye images can recognize the subject based on the target that had been set earlier during the training process. When the values between new eye image and the eye image in the database are almost equal, it is considered the eye image is matched.

Transcriptome Analysis of the Planarian Eye Identifies ovo as a Specific Regulator of Eye Regeneration

Directory of Open Access Journals (Sweden)

Sylvain W. Lapan

2012-08-01

Full Text Available Among the millions of invertebrate species with visual systems, the genetic basis of eye development and function is well understood only in Drosophila melanogaster. We describe an eye transcriptome for the planarian Schmidtea mediterranea. Planarian photoreceptors expressed orthologs of genes required for phototransduction and microvillus structure in Drosophila and vertebrates, and optic pigment cells expressed solute transporters and melanin synthesis enzymes similar to those active in the vertebrate retinal pigment epithelium. Orthologs of several planarian eye genes, such as bestrophin-1 and Usher syndrome genes, cause eye defects in mammals when perturbed and were not previously described to have roles in invertebrate eyes. Five previously undescribed planarian eye transcription factors were required for normal eye formation during head regeneration. In particular, a conserved, transcription-factor-encoding ovo gene was expressed from the earliest stages of eye regeneration and was required for regeneration of all cell types of the eye.

Transcriptome analysis of the planarian eye identifies ovo as a specific regulator of eye regeneration.

Science.gov (United States)

Lapan, Sylvain W; Reddien, Peter W

2012-08-30

Among the millions of invertebrate species with visual systems, the genetic basis of eye development and function is well understood only in Drosophila melanogaster. We describe an eye transcriptome for the planarian Schmidtea mediterranea. Planarian photoreceptors expressed orthologs of genes required for phototransduction and microvillus structure in Drosophila and vertebrates, and optic pigment cells expressed solute transporters and melanin synthesis enzymes similar to those active in the vertebrate retinal pigment epithelium. Orthologs of several planarian eye genes, such as bestrophin-1 and Usher syndrome genes, cause eye defects in mammals when perturbed and were not previously described to have roles in invertebrate eyes. Five previously undescribed planarian eye transcription factors were required for normal eye formation during head regeneration. In particular, a conserved, transcription-factor-encoding ovo gene was expressed from the earliest stages of eye regeneration and was required for regeneration of all cell types of the eye. Copyright © 2012 The Authors. Published by Elsevier Inc. All rights reserved.

Quantitative measurement of binocular color fusion limit for non-spectral colors.

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Jung, Yong Ju; Sohn, Hosik; Lee, Seong-il; Ro, Yong Man; Park, Hyun Wook

2011-04-11

Human perception becomes difficult in the event of binocular color fusion when the color difference presented for the left and right eyes exceeds a certain threshold value, known as the binocular color fusion limit. This paper discusses the binocular color fusion limit for non-spectral colors within the color gamut of a conventional LCD 3DTV. We performed experiments to measure the color fusion limit for eight chromaticity points sampled from the CIE 1976 chromaticity diagram. A total of 2480 trials were recorded for a single observer. By analyzing the results, the color fusion limit was quantified by ellipses in the chromaticity diagram. The semi-minor axis of the ellipses ranges from 0.0415 to 0.0923 in terms of the Euclidean distance in the u'v´ chromaticity diagram and the semi-major axis ranges from 0.0640 to 0.1560. These eight ellipses are drawn on the chromaticity diagram. © 2011 Optical Society of America

Eye Cancer

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... layer of tissue underneath the retina that contains connective tissue and melanocytes, which are pigmented (colored) cells, and nourishes the inside of the eye. The choroid is the most common site for a tumor. Types of intraocular cancer The most common intraocular cancer in adults is ...

Ask a Scientist: What is Color Blindness?

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Full Text Available ... t you see colors well in the dark? Do fish have eyelids? Why does saltwater sting your ... treated, and how people become color blind. What do my eyes do when I’m sleeping? Click ...

Color: Physics and Perception

Science.gov (United States)

Gilbert, Pupa

Unless we are colorblind, as soon as we look at something, we know what color it is. Simple, isn't it? No, not really. The color we see is rarely just determined by the physical color, that is, the wavelength of visible light associated with that color. Other factors, such as the illuminating light, or the brightness surrounding a certain color, affect our perception of that color. Most striking, and useful, is understanding how the retina and the brain work together to interpret the color we see, and how they can be fooled by additive color mixing, which makes it possible to have color screens and displays. I will show the physical origin of all these phenomena and give live demos as I explain how they work. Bring your own eyes! For more information: (1) watch TED talk: ``Color: Physics and Perception'' and (2) read book: PUPA Gilbert and W Haeberli ``Physics in the Arts'', ISBN 9780123918789.

A novel algorithm for automatic localization of human eyes

Institute of Scientific and Technical Information of China (English)

Liang Tao (陶亮); Juanjuan Gu (顾涓涓); Zhenquan Zhuang (庄镇泉)

2003-01-01

Based on geometrical facial features and image segmentation, we present a novel algorithm for automatic localization of human eyes in grayscale or color still images with complex background. Firstly, a determination criterion of eye location is established by the prior knowledge of geometrical facial features. Secondly,a range of threshold values that would separate eye blocks from others in a segmented face image (I.e.,a binary image) are estimated. Thirdly, with the progressive increase of the threshold by an appropriate step in that range, once two eye blocks appear from the segmented image, they will be detected by the determination criterion of eye location. Finally, the 2D correlation coefficient is used as a symmetry similarity measure to check the factuality of the two detected eyes. To avoid the background interference, skin color segmentation can be applied in order to enhance the accuracy of eye detection. The experimental results demonstrate the high efficiency of the algorithm and correct localization rate.

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.

Functional genomics identifies regulators of the phototransduction machinery in the Drosophila larval eye and adult ocelli.

Science.gov (United States)

Mishra, Abhishek Kumar; Bargmann, Bastiaan O R; Tsachaki, Maria; Fritsch, Cornelia; Sprecher, Simon G

2016-02-15

Sensory perception of light is mediated by specialized Photoreceptor neurons (PRs) in the eye. During development all PRs are genetically determined to express a specific Rhodopsin (Rh) gene and genes mediating a functional phototransduction pathway. While the genetic and molecular mechanisms of PR development is well described in the adult compound eye, it remains unclear how the expression of Rhodopsins and the phototransduction cascade is regulated in other visual organs in Drosophila, such as the larval eye and adult ocelli. Using transcriptome analysis of larval PR-subtypes and ocellar PRs we identify and study new regulators required during PR differentiation or necessary for the expression of specific signaling molecules of the functional phototransduction pathway. We found that the transcription factor Krüppel (Kr) is enriched in the larval eye and controls PR differentiation by promoting Rh5 and Rh6 expression. We also identified Camta, Lola, Dve and Hazy as key genes acting during ocellar PR differentiation. Further we show that these transcriptional regulators control gene expression of the phototransduction cascade in both larval eye and adult ocelli. Our results show that PR cell type-specific transcriptome profiling is a powerful tool to identify key transcriptional regulators involved during several aspects of PR development and differentiation. Our findings greatly contribute to the understanding of how combinatorial action of key transcriptional regulators control PR development and the regulation of a functional phototransduction pathway in both larval eye and adult ocelli. Copyright © 2015 Elsevier Inc. All rights reserved.

RED EYES ON WOLF-RAYET STARS: 60 NEW DISCOVERIES VIA INFRARED COLOR SELECTION

International Nuclear Information System (INIS)

Mauerhan, Jon C.; Van Dyk, Schuyler D.; Morris, Patrick W.

2011-01-01

We have spectroscopically identified 60 Galactic Wolf-Rayet (WR) stars, including 38 nitrogen types (WN) and 22 carbon types (WC). Using photometry from the Spitzer/GLIMPSE and Two Micron All Sky Survey databases, the new WRs were selected via a method we have established that exploits their unique infrared colors, which is mainly the result of excess radiation generated by free-free scattering within their dense ionized winds. The selection criterion has been refined since the last report, resulting in a WR detection rate of ∼20% in spectroscopic follow-up of candidates that comprise a broad color space defined by the color distribution of all known WRs having B > 14 mag. However, there are smaller regions within this color space that yield WRs at a rate of >50% in spectroscopic follow-up. Candidates that are not WRs are mainly Be stars, which is possibly attributable to the physical similarities between the free-free emission parameters of Be disks and WR winds. As an additional selection experiment, the list of WR candidates was cross-correlated with archival X-ray point-source catalogs, which increases the WR detection rate of the broad color space to ∼40%; 10 new WR X-ray sources have been found in addition to a previously unrecognized X-ray counterpart to a known WR. The extinction values, distances, and Galactocentric radii of all new WRs are calculated using the method of spectroscopic parallax. Although the majority of the new WRs have no obvious association with stellar clusters, two WC8 stars reside in a previously unknown massive-star cluster, in which five OB supergiants were also identified. The new system lies at an estimated distance of ∼6.1 kpc, near the intersection of the Scutum-Centaurus Arm with the Galaxy's bar. In addition, two WC and four WN stars, all but one of which are X-ray sources, were identified in association with the stellar clusters Danks 1 and 2. A WN9 star has also been associated with the cluster [DBS2003] 179. This work

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.

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

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

Science.gov (United States)

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

A Quarter Century of Variation in Color and Allometric Characteristics of Eggs from a Rain Forest Population of the Pearly-eyed Thrasher (Margarops fuscatus).

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WAYNE J. ARENDT

2004-01-01

Egg color, size, and shape vary considerably within and among female Pearly-eyed Thrashers (Margarops fuscatus). Results of a 25-yr study (1979-2004) are presented to provide comparative data. In a sample of 4,128 eggs, typical shape was prolate spheroid; but several variations were observed, depending on the age, stature, and physiological condition of the female, as...

Color improves ‘visual’ acuity via sound

Directory of Open Access Journals (Sweden)

Shelly eLevy-Tzedek

2014-11-01

Full Text Available Visual-to-auditory sensory substitution devices (SSDs convey visual information via sound, with the primary goal of making visual information accessible to blind and visually impaired individuals. We developed the EyeMusic SSD, which transforms shape, location and color information into musical notes. We tested the 'visual' acuity of 23 individuals (13 blind and 10 blindfolded sighted on the Snellen tumbling-E test, with the EyeMusic. Participants were asked to determine the orientation of the letter ‘E’. The test was repeated twice: in one test, the letter ‘E’ was drawn with a single color (white, and in the other test, with two colors (red and white. In the latter case, the vertical line in the letter, when upright, was drawn in red, with the three horizontal lines drawn in white. We found no significant differences in performance between the blind and the sighted groups. We found a significant effect of the added color on the ‘visual’ acuity. The highest acuity participants reached in the monochromatic test was 20/800, whereas with the added color, acuity doubled to 20/400. We conclude that color improves 'visual' acuity via sound.

Colored Contact Lens Dangers

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... Hazard: The Hidden Dangers of Buying Decorative Contact Lenses Without a Prescription Leer en Español: Peligros asociados ... truth." Real People, Real Problems with Colored Contact Lenses Julian: Teenager Blinded In One Eye By Non- ...

Colored Contact Lens Dangers

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Full Text Available ... about the members of the eye-care team . Consumer warning about the improper use of colored contact ... About the Academy Jobs at the Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms of ...

Colored Contact Lens Dangers

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Full Text Available ... about the members of the eye-care team . Consumer warning about the improper use of colored contact ... a laser pointer several times, according to a report published this month in the New England Journal ...

Colored Contact Lens Dangers

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Full Text Available ... like a suction cup." Halloween is a popular time for people to use colored contact lenses to ... wear costume contact lenses for Halloween or any time of year, follow these guidelines: Get an eye ...

Colored Contact Lens Dangers

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Full Text Available ... be purchased over-the-counter or on the Internet," says Thomas Steinemann, MD, professor of ophthalmology at ... about the members of the eye-care team . Consumer warning about the improper use of colored contact ...

Colored Contact Lens Dangers

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Full Text Available ... Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide Eye Health ... Leer en Español: Peligros asociados con los lentes de contacto de color Sep. 26, ...

Colored Contact Lens Dangers

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Full Text Available ... Cleveland. "This is far from the truth." Real People, Real Problems with Colored Contact Lenses Julian: Teenager ... the lenses. Never share contact lenses with another person. Get follow up exams with your eye care ...

A maximal chromatic expansion method of mapping multichannel imagery into color space. [North Dakota

Science.gov (United States)

Juday, R. D.; Abotteen, R. A. (Principal Investigator)

1978-01-01

The author has identified the following significant results. A color film generation method that maximally expands the chromaticity and aligns Kauth brightness with the gray axis was presented. In comparison with the current LACIE film product, the new color film product has more contrast and more colors and appears to be brighter. The field boundaries in the new product were more pronounced than in the current LACIE product. The speckle effect was one problem in the new product. The yellowness speckle can be treated using an equation. This equation can be used to eliminate any speckle introduced by the greenness. This product leads logically toward another that will employ quantitative colorimetry which will account for some of the eye's perception of color stimuli.

Genome-Wide Association Studies Identify Candidate Genes for Coat Color and Mohair Traits in the Iranian Markhoz Goat.

Science.gov (United States)

Nazari-Ghadikolaei, Anahit; Mehrabani-Yeganeh, Hassan; Miarei-Aashtiani, Seyed R; Staiger, Elizabeth A; Rashidi, Amir; Huson, Heather J

2018-01-01

The Markhoz goat provides an opportunity to study the genetics underlying coat color and mohair traits of an Angora type goat using genome-wide association studies (GWAS). This indigenous Iranian breed is valued for its quality mohair used in ceremonial garments and has the distinction of exhibiting an array of coat colors including black, brown, and white. Here, we performed 16 GWAS for different fleece (mohair) traits and coat color in 228 Markhoz goats sampled from the Markhoz Goat Research Station in Sanandaj, Kurdistan province, located in western Iran using the Illumina Caprine 50K beadchip. The Efficient Mixed Model Linear analysis was used to identify genomic regions with potential candidate genes contributing to coat color and mohair characteristics while correcting for population structure. Significant associations to coat color were found within or near the ASIP, ITCH, AHCY , and RALY genes on chromosome 13 for black and brown coat color and the KIT and PDGFRA genes on chromosome 6 for white coat color. Individual mohair traits were analyzed for genetic association along with principal components that allowed for a broader perspective of combined traits reflecting overall mohair quality and volume. A multitude of markers demonstrated significant association to mohair traits highlighting potential candidate genes of POU1F1 on chromosome 1 for mohair quality, MREG on chromosome 2 for mohair volume, DUOX1 on chromosome 10 for yearling fleece weight, and ADGRV1 on chromosome 7 for grease percentage. Variation in allele frequencies and haplotypes were identified for coat color and differentiated common markers associated with both brown and black coat color. This demonstrates the potential for genetic markers to be used in future breeding programs to improve selection for coat color and mohair traits. Putative candidate genes, both novel and previously identified in other species or breeds, require further investigation to confirm phenotypic causality and

Enhanced susceptibility of a transposable-element-bearing strain of Drosophila melanogaster to somatic eye-color mutations by ethyl nitrosourea, methyl nitrosourea, and X-rays

International Nuclear Information System (INIS)

Ryo, H.; Kondo, S.; Rasmuson, B.

1983-01-01

A strain of Drosophila with the genes z and w + plus a transposable element (TE) is about 3 times more sensitive than a strain without TE toward somatic eye-color mutations after larval exposure to ethyl nitrosourea, methyl nitrosourea and X-rays. The assay system with TE is simple, reliable, and sensitive for detecting somatic mutations induced in vivo by mutagens. (orig.)

Colored Contact Lens Dangers

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Full Text Available ... Hazard: The Hidden Dangers of Buying Decorative Contact Lenses Without a Prescription Leer en Español: Peligros asociados ... truth." Real People, Real Problems with Colored Contact Lenses Julian: Teenager Blinded In One Eye By Non- ...

21 CFR 70.5 - General restrictions on use of color additives.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false General restrictions on use of color additives. 70... GENERAL COLOR ADDITIVES General Provisions § 70.5 General restrictions on use of color additives. (a) Color additives for use in the area of the eye. No listing or certification of a color additive shall be...

False color viewing device

International Nuclear Information System (INIS)

Kronberg, J.W.

1992-01-01

A viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching the user's eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage. 7 figs

Impaired eye region search accuracy in children with autistic spectrum disorders.

Directory of Open Access Journals (Sweden)

John R Pruett

Full Text Available To explore mechanisms underlying reduced fixation of eyes in autism, children with autistic spectrum disorders (ASD and typically developing children were tested in five visual search experiments: simple color feature; color-shape conjunction; face in non-face objects; mouth region; and eye region. No group differences were found for reaction time profile shapes in any of the five experiments, suggesting intact basic search mechanics in children with ASD. Contrary to early reports in the literature, but consistent with other more recent findings, we observed no superiority for conjunction search in children with ASD. Importantly, children with ASD did show reduced accuracy for eye region search (p = .005, suggesting that eyes contribute less to high-level face representations in ASD or that there is an eye region-specific disruption to attentional processes engaged by search in ASD.

Impaired eye region search accuracy in children with autistic spectrum disorders.

Science.gov (United States)

Pruett, John R; Hoertel, Sarah; Constantino, John N; Moll, Angela LaMacchia; McVey, Kelly; Squire, Emma; Feczko, Eric; Povinelli, Daniel J; Petersen, Steven E

2013-01-01

To explore mechanisms underlying reduced fixation of eyes in autism, children with autistic spectrum disorders (ASD) and typically developing children were tested in five visual search experiments: simple color feature; color-shape conjunction; face in non-face objects; mouth region; and eye region. No group differences were found for reaction time profile shapes in any of the five experiments, suggesting intact basic search mechanics in children with ASD. Contrary to early reports in the literature, but consistent with other more recent findings, we observed no superiority for conjunction search in children with ASD. Importantly, children with ASD did show reduced accuracy for eye region search (p = .005), suggesting that eyes contribute less to high-level face representations in ASD or that there is an eye region-specific disruption to attentional processes engaged by search in ASD.

Genome-Wide Association Studies Identify Candidate Genes for Coat Color and Mohair Traits in the Iranian Markhoz Goat

Directory of Open Access Journals (Sweden)

Anahit Nazari-Ghadikolaei

2018-04-01

Full Text Available The Markhoz goat provides an opportunity to study the genetics underlying coat color and mohair traits of an Angora type goat using genome-wide association studies (GWAS. This indigenous Iranian breed is valued for its quality mohair used in ceremonial garments and has the distinction of exhibiting an array of coat colors including black, brown, and white. Here, we performed 16 GWAS for different fleece (mohair traits and coat color in 228 Markhoz goats sampled from the Markhoz Goat Research Station in Sanandaj, Kurdistan province, located in western Iran using the Illumina Caprine 50K beadchip. The Efficient Mixed Model Linear analysis was used to identify genomic regions with potential candidate genes contributing to coat color and mohair characteristics while correcting for population structure. Significant associations to coat color were found within or near the ASIP, ITCH, AHCY, and RALY genes on chromosome 13 for black and brown coat color and the KIT and PDGFRA genes on chromosome 6 for white coat color. Individual mohair traits were analyzed for genetic association along with principal components that allowed for a broader perspective of combined traits reflecting overall mohair quality and volume. A multitude of markers demonstrated significant association to mohair traits highlighting potential candidate genes of POU1F1 on chromosome 1 for mohair quality, MREG on chromosome 2 for mohair volume, DUOX1 on chromosome 10 for yearling fleece weight, and ADGRV1 on chromosome 7 for grease percentage. Variation in allele frequencies and haplotypes were identified for coat color and differentiated common markers associated with both brown and black coat color. This demonstrates the potential for genetic markers to be used in future breeding programs to improve selection for coat color and mohair traits. Putative candidate genes, both novel and previously identified in other species or breeds, require further investigation to confirm phenotypic

Ask a Scientist: What is Color Blindness?

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Full Text Available ... blindness, whether it can be treated, and how people become color blind. What do my eyes do when I’m sleeping? Click to Watch What does it mean to be nearsighted or farsighted? Click to Watch Do fish have eyelids? Click to Watch Why don’t all animal eyes look the same? Click to Watch Why ...

Change of color in resins by adding layers of color 'enamel'

International Nuclear Information System (INIS)

Lafuente Marin, David; Arce Navarro, Hilda

2007-01-01

The quantification of the color change is proposed at the time of employing enamel resin over dentine resin. Six resins color dentin and two color enamel were used. Five discs of resin were built of each resin, with a deameter of 10 mm and a thicjness of 2 mm. The reflectance spectrophotometer Color-Eye ® 7000-A were used, to obtain the values L*, a*, b* of the dentin resin disks and transposition of these with enamel. The conclusion has been that in the color have produced changes clinically detectable when put layers of enamel. The Resin Helio Fill Transparent has been which has produced major changes. Given the two enamel resins, dentin resin Helio Molar 310/B3 has been which has suffered major changes and Helio Fill A2 which has introduced fewer changes. Most resins have decreased the chroma, less the value. (author) [es

True color only exists in the eye of the observer

NARCIS (Netherlands)

Cornelissen, Frans W.; Brenner, Eli; Smeets, Jeroen

2003-01-01

The colors we perceive are the outcome of an attempt to meaningfully order the spectral information from the environment. These colors are not the result of a straightforward mapping of a physical property to a sensation, but arise from an interaction between our environment and our visual system.

Top-down expectancy versus bottom-up guidance in search for known color-form conjunctions.

Science.gov (United States)

Anderson, Giles M; Humphreys, Glyn W

2015-11-01

We assessed the effects of pairing a target object with its familiar color on eye movements in visual search, under conditions where the familiar color could or could not be predicted. In Experiment 1 participants searched for a yellow- or purple-colored corn target amongst aubergine distractors, half of which were yellow and half purple. Search was more efficient when the color of the target was familiar and early eye movements more likely to be directed to targets carrying a familiar color than an unfamiliar color. Experiment 2 introduced cues which predicted the target color at 80 % validity. Cue validity did not affect whether early fixations were to the target. Invalid cues, however, disrupted search efficiency for targets in an unfamiliar color whilst there was little cost to search efficiency for targets in their familiar color. These results generalized across items with different colors (Experiment 3). The data are consistent with early processes in selection being automatically modulated in a bottom-up manner to targets in their familiar color, even when expectancies are set for other colors.

Advanced Color Image Processing and Analysis

CERN Document Server

2013-01-01

This volume does much more than survey modern advanced color processing. Starting with a historical perspective on ways we have classified color, it sets out the latest numerical techniques for analyzing and processing colors, the leading edge in our search to accurately record and print what we see. The human eye perceives only a fraction of available light wavelengths, yet we live in a multicolor world of myriad shining hues. Colors rich in metaphorical associations make us “purple with rage” or “green with envy” and cause us to “see red.” Defining colors has been the work of centuries, culminating in today’s complex mathematical coding that nonetheless remains a work in progress: only recently have we possessed the computing capacity to process the algebraic matrices that reproduce color more accurately. With chapters on dihedral color and image spectrometers, this book provides technicians and researchers with the knowledge they need to grasp the intricacies of today’s color imaging.

Physics and psychophysics of color reproduction

Science.gov (United States)

Giorgianni, Edward J.

1991-08-01

The successful design of a color-imaging system requires knowledge of the factors used to produce and control color. This knowledge can be derived, in part, from measurements of the physical properties of the imaging system. Color itself, however, is a perceptual response and cannot be directly measured. Though the visual process begins with physics, as radiant energy reaching the eyes, it is in the mind of the observer that the stimuli produced from this radiant energy are interpreted and organized to form meaningful perceptions, including the perception of color. A comprehensive understanding of color reproduction, therefore, requires not only a knowledge of the physical properties of color-imaging systems but also an understanding of the physics, psychophysics, and psychology of the human observer. The human visual process is quite complex; in many ways the physical properties of color-imaging systems are easier to understand.

Color extended visual cryptography using error diffusion.

Science.gov (United States)

Kang, InKoo; Arce, Gonzalo R; Lee, Heung-Kyu

2011-01-01

Color visual cryptography (VC) encrypts a color secret message into n color halftone image shares. Previous methods in the literature show good results for black and white or gray scale VC schemes, however, they are not sufficient to be applied directly to color shares due to different color structures. Some methods for color visual cryptography are not satisfactory in terms of producing either meaningless shares or meaningful shares with low visual quality, leading to suspicion of encryption. This paper introduces the concept of visual information pixel (VIP) synchronization and error diffusion to attain a color visual cryptography encryption method that produces meaningful color shares with high visual quality. VIP synchronization retains the positions of pixels carrying visual information of original images throughout the color channels and error diffusion generates shares pleasant to human eyes. Comparisons with previous approaches show the superior performance of the new method.

Color management of porcelain veneers: influence of dentin and resin cement colors.

Science.gov (United States)

Dozic, Alma; Tsagkari, Maria; Khashayar, Ghazal; Aboushelib, Moustafa

2010-01-01

Porcelain veneers have become an interesting treatment option to correct the shape and color of anterior teeth. Because of their limited thickness and high translucency, achieving a good color match is influenced by several variables. The aim of this work was to investigate the influence of natural dentin and resin cement colors on final color match of porcelain veneers. A preselected shade tab (A1) was chosen as the target color for a maxillary central incisor, and its color parameters (L*a*b*) were measured using a digital spectrophotometer (SpectroShade, MHT). Nine natural dentin colors (Natural Die Material, Ivoclar Vivadent) representing a wide range of tooth colors were used to prepare resin replicas of the maxillary central incisor with a standard preparation for porcelain veneers. The prepared porcelain veneers (IPS Empress Esthetic, A1, 0.6 mm thick, Ivoclar Vivadent) were cemented on the resin dies (nine groups of natural dentin colors) using seven shades of resin cement (Variolink Veneers, Ivoclar Vivadent). The L*a*b* values of the cemented veneers were measured, and DE values were calculated against the preselected target color (A1). DE greater than 3.3 was considered as a significant color mismatch detectable by the human eye. The seven shades of resin cement had no significant influence on the final color of the veneers, as the measured DE values were almost identical for every test group. On the other hand, the color of natural dentin was a significant factor that influenced final color match. None of the 63 tested combinations (nine natural dentin colors and seven resin cement colors) produced an acceptable color match. Thin porcelain veneers cannot mask underlying tooth color even when different shades of resin cement are used. Incorporation of opaque porcelain (high chroma) may improve final color match.

Development of the RGB LEDs color mixing mechanism for stability the color temperature at different projection distances.

Science.gov (United States)

Hung, Chih-Ching

2015-01-01

In lighting application, the color mixing of the RGB LEDs can provide more color selection in correlated color temperature and color rendering. Therefore, the purpose of this study is to propose a RGB color mixing mechanism by applying the mechanism design. Three sets of lamp-type RGB LEDs are individually installed on three four-bar linkages. A crank is used to drive three groups of RGB LEDs lamp-type to project lights onto a single plane in order to mix the lights. And, simulations of the illuminance and associated color temperatures are conducted by changing the distance to the projection plane, under the assumption that the stability of the color temperature of the projected light does not change according to the projecting height. Thus, the effect of change in the color temperature on color determination by the humans' eyes was avoided. The success of the proposed method will allow medical personnel to choose suitable wavelengths and color temperatures according to the particular requirements of their medical-examination environments.

Full-color OLED on silicon microdisplay

Science.gov (United States)

Ghosh, Amalkumar P.

2002-02-01

eMagin has developed numerous enhancements to organic light emitting diode (OLED) technology, including a unique, up- emitting structure for OLED-on-silicon microdisplay devices. Recently, eMagin has fabricated full color SVGA+ resolution OLED microdisplays on silicon, with over 1.5 million color elements. The display is based on white light emission from OLED followed by LCD-type red, green and blue color filters. The color filters are patterned directly on OLED devices following suitable thin film encapsulation and the drive circuits are built directly on single crystal silicon. The resultant color OLED technology, with hits high efficiency, high brightness, and low power consumption, is ideally suited for near to the eye applications such as wearable PCS, wireless Internet applications and mobile phone, portable DVD viewers, digital cameras and other emerging applications.

Comprehensive eye evaluation algorithm

Science.gov (United States)

Agurto, C.; Nemeth, S.; Zamora, G.; Vahtel, M.; Soliz, P.; Barriga, S.

2016-03-01

In recent years, several research groups have developed automatic algorithms to detect diabetic retinopathy (DR) in individuals with diabetes (DM), using digital retinal images. Studies have indicated that diabetics have 1.5 times the annual risk of developing primary open angle glaucoma (POAG) as do people without DM. Moreover, DM patients have 1.8 times the risk for age-related macular degeneration (AMD). Although numerous investigators are developing automatic DR detection algorithms, there have been few successful efforts to create an automatic algorithm that can detect other ocular diseases, such as POAG and AMD. Consequently, our aim in the current study was to develop a comprehensive eye evaluation algorithm that not only detects DR in retinal images, but also automatically identifies glaucoma suspects and AMD by integrating other personal medical information with the retinal features. The proposed system is fully automatic and provides the likelihood of each of the three eye disease. The system was evaluated in two datasets of 104 and 88 diabetic cases. For each eye, we used two non-mydriatic digital color fundus photographs (macula and optic disc centered) and, when available, information about age, duration of diabetes, cataracts, hypertension, gender, and laboratory data. Our results show that the combination of multimodal features can increase the AUC by up to 5%, 7%, and 8% in the detection of AMD, DR, and glaucoma respectively. Marked improvement was achieved when laboratory results were combined with retinal image features.

The Evaluation of Yellow vs. Blue Color Contrast Sensitivity pre and Post LASIK

Directory of Open Access Journals (Sweden)

S. Heydarian

2007-06-01

Full Text Available Introduction: contrast sensitivity is one of the most important psychophysical tests that may be used for the evaluation of refractive state of eye and retinal image quality. Yellow vs. blue color contrast sensitivity may be more suitable in this regard. Materials and Methods: thirty myopic eyes were considered in this study. Yellow vs. blue color contrast sensitivity was evaluated under the same environment and conditions in these individuals pre and post LASIK. Results: The comparison of yellow vs. blue color contrast sensitivity with glasses pr e and post LASIK shows a significant improvement (p

Color Difference Threshold of Chromostereopsis Induced by Flat Display Emission

Directory of Open Access Journals (Sweden)

Maris eOzolinsh

2015-04-01

Full Text Available The study of chromostereopsis has gained attention in the backdrop of the use of computer displays in daily life. In this context, we analyze the illusory depth sense using planar color images presented on a computer screen. We determine the color difference threshold required to induce an illusory sense of depth psychometrically using a constant stimuli paradigm. Isoluminant stimuli are presented on a computer screen, which stimuli are aligned along the blue-red line in the computer display CIE xyY color chart. Stereo disparity is generated by increasing the color difference between the central and surrounding areas of the stimuli with both areas consisting of random dots on a black background. The observed altering of illusory dept sense, thus also stereo disparity is validated using the center-of-gravity model. The induced illusory sense of the depth effect undergoes color reversal upon varying the binocular lateral eye pupil covering conditions (lateral or medial. Analysis of the retinal image point spread function for the display red and blue pixel radiation validates the altering of chromostereopsis retinal disparity achieved by increasing the color difference, and also the chromostereopsis color reversal caused by varying the eye pupil covering conditions.

The technology study on irradiation sterilization of the eye health care paste

International Nuclear Information System (INIS)

Yang Mingcheng; Zhu Jun; Zhao Huidong; Song Weidong; Zhang Hongna; Li Kunhao

2009-01-01

The effect of radiation on appearance,color and active ingredients of products has been studied in irradiation sterilization of eye healthy care paste by use of 60 Co γ-rays. The results show that irradiation is very effective on killing the microorganisms in eye healthy care paste, and the D 10 of the aerobic bacterial count is determined to be 3.16kGy. The process adopts the irradiation static stacking mode, and the suitable absorbed dose has been selected to be 7-8kGy. It has been found that irradiation with 7-8kGy does not affect appearance, color and active ingredients of the eye healthy care paste. (authors)

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.

Association of genetic variants with self-assessed color categories in Brazilians.

Directory of Open Access Journals (Sweden)

Danielle Fernandes Durso

Full Text Available The Brazilian population was formed by extensive admixture of three different ancestral roots: Amerindians, Europeans and Africans. Our previous work has shown that at an individual level, ancestry, as estimated using molecular markers, was a poor predictor of color in Brazilians. We now investigate if SNPs known to be associated with human skin pigmentation can be used to predict color in Brazilians. For that, we studied the association of fifteen SNPs, previously known to be linked with skin color, in 243 unrelated Brazilian individuals self-identified as White, Browns or Blacks from Rio de Janeiro and 212 unrelated Brazilian individuals self-identified as White or Blacks from São Paulo. The significance of association of SNP genotypes with self-assessed color was evaluated using partial regression analysis. After controlling for ancestry estimates as covariates, only four SNPs remained significantly associated with skin pigmentation: rs1426654 and rs2555364 within SLC24A5, rs16891982 at SLC45A2 and rs1042602 at TYR. These loci are known to be involved in melanin synthesis or transport of melanosomes. We found that neither genotypes of these SNPs, nor their combination with biogeographical ancestry in principal component analysis, could predict self-assessed color in Brazilians at an individual level. However, significant correlations did emerge at group level, demonstrating that even though elements other than skin, eye and hair pigmentation do influence self-assessed color in Brazilians, the sociological act of self-classification is still substantially dependent of genotype at these four SNPs.

A quantitative measurement of binocular color fusion limit for different disparities

Science.gov (United States)

Chen, Zaiqing; Shi, Junsheng; Tai, Yonghan; Huang, Xiaoqiao; Yun, Lijun; Zhang, Chao

2018-01-01

Color asymmetry is a common phenomenon in stereoscopic display system, which can cause visual fatigue or visual discomfort. When the color difference between the left and right eyes exceeds a threshold value, named binocular color fusion limit, color rivalry is said to occur. The most important information brought by stereoscopic displays is the depth perception produced by the disparity. As the stereo pair stimuli are presented separately to both eyes with disparities and those two monocular stimuli differ in color but share an iso-luminance polarity, it is possible for stereopsis and color rivalry to coexist. In this paper, we conducted an experiment to measure the color fusion limit for different disparity levels. In particular, it examines how the magnitude and sign of disparity affect the binocular color fusion limit that yields a fused, stable stereoscopic percept. The binocular color fusion limit was measured at five levels of disparities: 0, +/-60, +/-120 arc minutes for a sample color point which was selected from the 1976 CIE u'v' chromaticity diagram. The experimental results showed that fusion limit for the sample point varied with the level and sign of disparity. It was an interesting result that the fusion limit increased as the disparity decreases at crossed disparity direction (sign -), but there is almost no big change at uncrossed disparity direction (sign +). We found that color fusion was more difficult to achieve at the crossed disparity direction than at the uncrossed disparity direction.

Semantic guidance of eye movements in real-world scenes

OpenAIRE

Hwang, Alex D.; Wang, Hsueh-Cheng; Pomplun, Marc

2011-01-01

The perception of objects in our visual world is influenced by not only their low-level visual features such as shape and color, but also their high-level features such as meaning and semantic relations among them. While it has been shown that low-level features in real-world scenes guide eye movements during scene inspection and search, the influence of semantic similarity among scene objects on eye movements in such situations has not been investigated. Here we study guidance of eye movemen...

A color hierarchy for automatic target selection.

Directory of Open Access Journals (Sweden)

Illia Tchernikov

Full Text Available Visual processing of color starts at the cones in the retina and continues through ventral stream visual areas, called the parvocellular pathway. Motion processing also starts in the retina but continues through dorsal stream visual areas, called the magnocellular system. Color and motion processing are functionally and anatomically discrete. Previously, motion processing areas MT and MST have been shown to have no color selectivity to a moving stimulus; the neurons were colorblind whenever color was presented along with motion. This occurs when the stimuli are luminance-defined versus the background and is considered achromatic motion processing. Is motion processing independent of color processing? We find that motion processing is intrinsically modulated by color. Color modulated smooth pursuit eye movements produced upon saccading to an aperture containing a surface of coherently moving dots upon a black background. Furthermore, when two surfaces that differed in color were present, one surface was automatically selected based upon a color hierarchy. The strength of that selection depended upon the distance between the two colors in color space. A quantifiable color hierarchy for automatic target selection has wide-ranging implications from sports to advertising to human-computer interfaces.

THE EYE — MIRROR OF CARDIOVASCULAR DISORDER. RELATIONSHIP OF THE RETINA FUNCTIONAL STATE AND THE HYPERTENSION SEVERITY

Directory of Open Access Journals (Sweden)

V. S. Zadionchenko

2011-01-01

Full Text Available Aim. To study the retina state by functional methods in patients with arterial hypertension (HT of various degrees. Material and methods. Patients with uncomplicated HT of 1-3 degrees (n=81 and healthy subjects (n=20 of control group were examined. Routine (direct ophthalmoscopy and functional (evaluation of contrast and color sensitivity of the retina, electroretinography methods were used. Results. Functional retinal changes (reduction in color and contrast sensitivity progressed with increasing HT degree. These changes were located in the area of central retinal artery (paramacular area and area of choroidal blood flow (macular region. Retinal bioelectrical activity disturbance was also found by the electroretinography. Conclusion. The identified functional disorders suggest the retina involvement in the pathological process even in the early HT and may be associated with its severity. It confirms a relationship of HT with disorders of eye as a target organ in HT. Published data and results of our studies can refute the point of view about impossibility of changes assessment on the eye fundus in patients with uncomplicated HT, and indicates that it was premature exclusion of the eye from the list of target organs in HT.

Colored Chaos

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] Released 7 May 2004 This daytime visible color image was collected on May 30, 2002 during the Southern Fall season in Atlantis Chaos. The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation. Image information: VIS instrument. Latitude -34.5, Longitude 183.6 East (176.4 West). 38 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D

Ask a Scientist: What is Color Blindness?

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Full Text Available ... you see colors well in the dark? Do fish have eyelids? Why does saltwater sting your eyes? ... be nearsighted or farsighted? Click to Watch Do fish have eyelids? Click to Watch Why don’t ...

A study of glasses-type color CGH using a color filter considering reduction of blurring

Science.gov (United States)

Iwami, Saki; Sakamoto, Yuji

2009-02-01

We have developed a glasses-type color computer generated hologram (CGH) by using a color filter. The proposed glasses consist of two "lenses" made of overlapping holograms and color filters. The holograms, which are calculated to reconstruct images in each primary color, are divided to small areas, which we called cells, and superimposed on one hologram. In the same way, colors of the filter correspond to the hologram cells. We can configure it very simply without a complex optical system, and the configuration yields a small and light weight system suitable for glasses. When the cell is small enough, the colors are mixed and reconstructed color images are observed. In addition, color expression of reconstruction images improves, too. However, using small cells blurrs reconstructed images because of the following reasons: (1) interference between cells because of the correlation with the cells, and (2) reduction of resolution caused by the size of the cell hologram. We are investigating in order to make a hologram that has high resolution reconstructed color images without ghost images. In this paper, we discuss (1) the details of the proposed glasses-type color CGH, (2) appropriate cell size for an eye system, (3) effects of cell shape on the reconstructed images, and (4) a new method to reduce the blurring of the images.

Adaptive pseudo-color enhancement method of weld radiographic images based on HSI color space and self-transformation of pixels

Science.gov (United States)

Jiang, Hongquan; Zhao, Yalin; Gao, Jianmin; Gao, Zhiyong

2017-06-01

The radiographic testing (RT) image of a steam turbine manufacturing enterprise has the characteristics of low gray level, low contrast, and blurriness, which lead to a substandard image quality. Moreover, it is not conducive for human eyes to detect and evaluate defects. This study proposes an adaptive pseudo-color enhancement method for weld radiographic images based on the hue, saturation, and intensity (HSI) color space and the self-transformation of pixels to solve these problems. First, the pixel's self-transformation is performed to the pixel value of the original RT image. The function value after the pixel's self-transformation is assigned to the HSI components in the HSI color space. Thereafter, the average intensity of the enhanced image is adaptively adjusted to 0.5 according to the intensity of the original image. Moreover, the hue range and interval can be adjusted according to personal habits. Finally, the HSI components after the adaptive adjustment can be transformed to display in the red, green, and blue color space. Numerous weld radiographic images from a steam turbine manufacturing enterprise are used to validate the proposed method. The experimental results show that the proposed pseudo-color enhancement method can improve image definition and make the target and background areas distinct in weld radiographic images. The enhanced images will be more conducive for defect recognition. Moreover, the image enhanced using the proposed method conforms to the human eye visual properties, and the effectiveness of defect recognition and evaluation can be ensured.

Adaptive pseudo-color enhancement method of weld radiographic images based on HSI color space and self-transformation of pixels.

Science.gov (United States)

Jiang, Hongquan; Zhao, Yalin; Gao, Jianmin; Gao, Zhiyong

2017-06-01

The radiographic testing (RT) image of a steam turbine manufacturing enterprise has the characteristics of low gray level, low contrast, and blurriness, which lead to a substandard image quality. Moreover, it is not conducive for human eyes to detect and evaluate defects. This study proposes an adaptive pseudo-color enhancement method for weld radiographic images based on the hue, saturation, and intensity (HSI) color space and the self-transformation of pixels to solve these problems. First, the pixel's self-transformation is performed to the pixel value of the original RT image. The function value after the pixel's self-transformation is assigned to the HSI components in the HSI color space. Thereafter, the average intensity of the enhanced image is adaptively adjusted to 0.5 according to the intensity of the original image. Moreover, the hue range and interval can be adjusted according to personal habits. Finally, the HSI components after the adaptive adjustment can be transformed to display in the red, green, and blue color space. Numerous weld radiographic images from a steam turbine manufacturing enterprise are used to validate the proposed method. The experimental results show that the proposed pseudo-color enhancement method can improve image definition and make the target and background areas distinct in weld radiographic images. The enhanced images will be more conducive for defect recognition. Moreover, the image enhanced using the proposed method conforms to the human eye visual properties, and the effectiveness of defect recognition and evaluation can be ensured.

Color improves “visual” acuity via sound

OpenAIRE

Levy-Tzedek, Shelly; Riemer, Dar; Amedi, Amir

2014-01-01

Visual-to-auditory sensory substitution devices (SSDs) convey visual information via sound, with the primary goal of making visual information accessible to blind and visually impaired individuals. We developed the EyeMusic SSD, which transforms shape, location, and color information into musical notes. We tested the “visual” acuity of 23 individuals (13 blind and 10 blindfolded sighted) on the Snellen tumbling-E test, with the EyeMusic. Participants were asked to determine the orientation of...

The function of animal ‘eyespots’: conspicuousness but not eye mimicry is key

Directory of Open Access Journals (Sweden)

Martin STEVENS

2009-10-01

Full Text Available Many animals are marked with conspicuous circular features often called ‘eyespots’, which intimidate predators, preventing or halting an attack. It has long been assumed that eyespots work by mimicking the eyes of larger animals, but recent experiments have indicated that conspicuousness and contrast is important in eyespot function, and not eye mimicry. We undertake two further experiments to distinguish between the conspicuousness and mimicry hypotheses, by using artificial prey presented to wild avian predators in the field. In experiment 1, we test if eyespot effectiveness depends on the marking shape (bar or circle and arrangement (eye-like and non-eye-like positions. We find no difference between shapes or arrangement; all spots were equally effective in scaring birds. In experiment 2, we test if the often yellow and black colors of eyespots mimic the eyes of birds of prey. We find no effect of shape, and no advantage to yellow and black spots over non-eye-like but equally conspicuous colors. The consistent finding is that eyespot function lies in being a conspicuous signal to predators, and not necessarily due to eye mimicry [Current Zoology 55 (5: –2009].

Color constancy in dermatoscopy with smartphone

Science.gov (United States)

Cugmas, Blaž; Pernuš, Franjo; Likar, Boštjan

2017-12-01

The recent spread of cheap dermatoscopes for smartphones can empower patients to acquire images of skin lesions on their own and send them to dermatologists. Since images are acquired by different smartphone cameras under unique illumination conditions, the variability in colors is expected. Therefore, the mobile dermatoscopic systems should be calibrated in order to ensure the color constancy in skin images. In this study, we have tested a dermatoscope DermLite DL1 basic, attached to Samsung Galaxy S4 smartphone. Under the controlled conditions, jpeg images of standard color patches were acquired and a model between an unknown device-dependent RGB and a deviceindependent Lab color space has been built. Results showed that median and the best color error was 7.77 and 3.94, respectively. Results are in the range of a human eye detection capability (color error ≈ 4) and video and printing industry standards (color error is expected to be between 5 and 6). It can be concluded that a calibrated smartphone dermatoscope can provide sufficient color constancy and can serve as an interesting opportunity to bring dermatologists closer to the patients.

Preferred skin color enhancement for photographic color reproduction

Science.gov (United States)

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.

Ask a Scientist: What is Color Blindness?

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Full Text Available ... Stuff Cool Eye Tricks Links to More Information Optical Illusions Printables Ask a Scientist Video Series Why can’ ... a scientist? Click to Watch What is an optical illusion? Click to Watch What is color blindness? Click ...

P1-13: Color Induction from Surround Color under Interocular Suppression

Directory of Open Access Journals (Sweden)

Ichiro Kuriki

2012-10-01

Full Text Available The effect of surround colors on color appearance is known to subserve color constancy in humans, but how multiple mechanisms in the visual system are involved in this effect is controversial. We used an interocular-suppression technique to examine how the effect occurs at the level higher than the interaction of binocular information. A test color chip (1.7 × 1.7 deg visual angle was presented in a static surround either with continuous-flash suppression in the dominant eye (CFS condition to make the surround inperceptible or without the suppression (no-CFS condition. The surround stimulus was either a Mondrian or a uniform field of the same mean chromaticity. Stimuli were simulated OSA color chips under red, white (D65, or green illuminant color and were presented on a CRT display. Unique yellows were measured by asking the subjects to judge whether the test stimulus appeared reddish or greenish. Two sizes of the surround stimuli (widths of 1 deg and 4 deg were used. Results showed significant shifts in unique yellow even under the CFS conditions, except for the 1 deg uniform-surround condition. Under the no-CFS condition, the shifts showed remarkable difference between subjects, except for the 4 deg Mondrian-surround condition. Interestingly, trends of the shifts showed high consistency within each subject, across conditions. These results indicate that mechanisms at both higher and lower levels than the neuronal site of interocular suppression are involved, and that the color shifts follow each subject's strategy in the higher-order mechanisms when only insufficient clues are available in the surround to estimate illuminant color.

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.

The eye amputated - consequences of eye amputation with emphasis on clinical aspects, phantom eye syndrome and quality of life.

Science.gov (United States)

Rasmussen, Marie Louise Roed

2010-12-01

In this thesis the term eye amputation (EA) covers the removing of an eye by: evisceration, enucleation and exenteration. Amputation of an eye is most frequently the end-stage in a complicated disease, or the primary treatment in trauma and neoplasm. In 2010 the literature is extensive due to knowledge about types of surgery, implants and surgical technique. However, not much is known about the time past surgery. To identify the number of EA, the causative diagnosis and the indication for surgical removal of the eye, the chosen surgical technique and to evaluate a possible change in surgical technique in Denmark from 1996 until 2003 (paper I); To describe the phantom eye syndrome and its prevalence of visual hallucinations, phantom pain and phantom sensations (paper II); To characterise the quality of phantom eye pain, including its intensity and frequency among EA patients. We attempted to identify patients with increased risk of developing pain after EA and investigated if preoperative pain is a risk factor for a later development of phantom pain (paper III); In addition we wanted to investigate the health related quality of life, perceived stress, self rated health, job separation due to illness or disability and socio-economic position of the EA in comparison with the general Danish population (paper IV). Records on 431 EA patients, clinical ophthalmological examination and an interview study of 173 EA patients and a questionnaire answered by 120 EA patients. The most frequent indications for EA in Denmark were painful blind eye (37%) and neoplasm (34%). During the study period 1996-2003, the annual number of eye amputations was stable, but an increase in bulbar eviscerations was noticed. Orbital implants were used with an increasing tendency until 2003. The Phantom eye syndrome is frequent among EA patients. Visual hallucinations were described by 42% of the patients. The content were mainly elementary visual hallucinations, with white or colored light as a

Eye readable metal hydride based hydrogen tape sensor for health applications

NARCIS (Netherlands)

Ngene, P.; Radeva, T.; Westerwaal, R.; Schreuders, H.; Dam, B.

Using the change in the intrinsic optical properties of YMg-based thin films upon exposure to hydrogen, we observe the presence of hydrogen at concentrations as low as 20 ppm just by a change in color. The eye-visible color change circumvents the use of any electronics in this device, thereby making

Weakener of white (Wow), a gene that modifies the expression of the white eye color locus and that suppresses position effect variegation in Drosophila melanogaster.

Science.gov (United States)

Birchler, J A; Bhadra, U; Rabinow, L; Linsk, R; Nguyen-Huynh, A T

1994-08-01

A locus is described in Drosophila melanogaster that modifies the expression of the white eye color gene. This trans-acting modifier reduces the expression of the white gene in the eye, but elevates the expression in other adult tissues. Because of the eye phenotype in which the expression of white is lessened but not eliminated, the newly described locus is called the Weakener of white (Wow). Northern analysis reveals that Wow can exert an inverse or direct modifying effect depending upon the developmental stage. Two related genes, brown and scarlet, that are coordinately expressed with white, are also affected by Wow. In addition, Wow modulates the steady state RNA level of the retrotransposon, copia. When tested with a white promoter-Alcohol dehydrogenase reporter. Wow confers the modifying effect to the reporter, suggesting a requirement of the white regulatory sequences for mediating the response. In addition to being a dosage sensitive regulator of white, brown, scarlet and copia, Wow acts as a suppressor of position effect variegation. There are many dosage sensitive suppressors of position effect variegation and many dosage-sensitive modifiers of gene expression. The Wow mutations provide evidence for an overlap between the two types of modifiers.

A survey of prosthetic eye wearers to investigate mucoid discharge

Directory of Open Access Journals (Sweden)

Pine K

2012-05-01

Full Text Available Keith Pine1, Brian Sloan2, Joanna Stewart3, Robert J Jacobs11Department of Optometry and Vision Science, 2Department of Ophthalmology, New Zealand National Eye Centre, 3Section of Epidemiology and Biostatistics, School of Population Health, University of Auckland, Auckland, New ZealandBackground: This study aimed to better understand the causes and treatments of mucoid discharge associated with prosthetic eye wear by reviewing the literature and surveying anophthalmic patients.Methods: An anonymous questionnaire was completed by 429 prosthetic eye wearers who used visual analog scales to self-measure their discharge experience for four discharge characteristics: frequency, color, volume, and viscosity. These characteristics were analyzed with age, ethnicity, years wearing a prosthesis, eye loss cause, removal and cleaning regimes, hand-washing behavior, age of current prosthesis, and professional repolishing regimes as explanatory variables. Eighteen ocularists’ Web sites containing comments on the cause and treatment of discharge were surveyed.Results: Associations were found between discharge frequency and cleaning regimes with more frequent cleaning accompanying more frequent discharge. Color was associated with years of wearing and age, with more years of wearing and older people having less colored discharge. Volume was associated with cleaning regimes with more frequent cleaners having more volume. Viscosity was associated with cleaning regimes and years of wearing with more frequent cleaning and shorter wearing time accompanying more viscous discharge. No associations were found between discharge characteristics and ethnicity, eye loss cause, hand washing, age of current prosthesis, or repolishing regimes. Forty-seven percent of ocularists’ Web sites advised that discharge was caused by surface deposits on the prosthesis, 29% by excessive handling of the prosthesis, and 24% by other causes.Conclusions: A standardized treatment

Genetic and phenotypic variability of iris color in Buenos Aires population

Directory of Open Access Journals (Sweden)

Diana María Hohl

Full Text Available Abstract The aim of this work was to describe the phenotypic and genotypic variability related to iris color for the population of Buenos Aires province (Argentina, and to assess the usefulness of current methods of analysis for this country. We studied five Single Nucleotide Polymorphisms (SNPs included in the IrisPlex kit, in 118 individuals, and we quantified eye color with Digital Iris Analysis Tool. The markers fit Hardy-Weinberg equilibrium for the whole sample, but not for rs12913832 within the group of brown eyes (LR=8.429; p=0.004. We found a remarkable association of HERC2 rs12913832 GG with blue color (p < 0.01 but the other markers did not show any association with iris color. The results for the Buenos Aires population differ from those of other populations of the world for these polymorphisms (p < 0,01. The differences we found might respond to the admixed ethnic composition of Argentina; therefore, methods of analysis used in European populations should be carefully applied when studying the population of Argentina. These findings reaffirm the importance of this investigation in the Argentinian population for people identification based on iris color.

Spectral optimization simulation of white light based on the photopic eye-sensitivity curve

International Nuclear Information System (INIS)

Dai, Qi; Hao, Luoxi; Lin, Yi; Cui, Zhe

2016-01-01

Spectral optimization simulation of white light is studied to boost maximum attainable luminous efficacy of radiation at high color-rendering index (CRI) and various color temperatures. The photopic eye-sensitivity curve V(λ) is utilized as the dominant portion of white light spectra. Emission spectra of a blue InGaN light-emitting diode (LED) and a red AlInGaP LED are added to the spectrum of V(λ) to match white color coordinates. It is demonstrated that at the condition of color temperature from 2500 K to 6500 K and CRI above 90, such white sources can achieve spectral efficacy of 330–390 lm/W, which is higher than the previously reported theoretical maximum values. We show that this eye-sensitivity-based approach also has advantages on component energy conversion efficiency compared with previously reported optimization solutions

Spectral optimization simulation of white light based on the photopic eye-sensitivity curve

Energy Technology Data Exchange (ETDEWEB)

Dai, Qi, E-mail: qidai@tongji.edu.cn [College of Architecture and Urban Planning, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Institute for Advanced Study, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Key Laboratory of Ecology and Energy-saving Study of Dense Habitat (Tongji University), Ministry of Education, 1239 Siping Road, Shanghai 200092 (China); Hao, Luoxi; Lin, Yi; Cui, Zhe [College of Architecture and Urban Planning, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Key Laboratory of Ecology and Energy-saving Study of Dense Habitat (Tongji University), Ministry of Education, 1239 Siping Road, Shanghai 200092 (China)

2016-02-07

Spectral optimization simulation of white light is studied to boost maximum attainable luminous efficacy of radiation at high color-rendering index (CRI) and various color temperatures. The photopic eye-sensitivity curve V(λ) is utilized as the dominant portion of white light spectra. Emission spectra of a blue InGaN light-emitting diode (LED) and a red AlInGaP LED are added to the spectrum of V(λ) to match white color coordinates. It is demonstrated that at the condition of color temperature from 2500 K to 6500 K and CRI above 90, such white sources can achieve spectral efficacy of 330–390 lm/W, which is higher than the previously reported theoretical maximum values. We show that this eye-sensitivity-based approach also has advantages on component energy conversion efficiency compared with previously reported optimization solutions.

Anticipatory eye movements and long-term memory in early infancy.

Science.gov (United States)

Wong-Kee-You, Audrey M B; Adler, Scott A

2016-11-01

Advances in our understanding of long-term memory in early infancy have been made possible by studies that have used the Rovee-Collier's mobile conjugate reinforcement paradigm and its variants. One function that has been attributed to long-term memory is the formation of expectations (Rovee-Collier & Hayne, 1987); consequently, a long-term memory representation should be established during expectation formation. To examine this prediction and potentially open the door on a new paradigm for exploring infants' long-term memory, using the Visual Expectation Paradigm (Haith, Hazan, & Goodman, 1988), 3-month-old infants were trained to form an expectation for predictable color and spatial information of picture events and emit anticipatory eye movements to those events. One day later, infants' anticipatory eye movements decreased in number relative to the end of training when the predictable colors were changed but not when the spatial location of the predictable color events was changed. These findings confirm that information encoded during expectation formation are stored in long-term memory, as hypothesized by Rovee-Collier and colleagues. Further, this research suggests that eye movements are potentially viable measures of long-term memory in infancy, providing confirmatory evidence for early mnemonic processes. © 2016 Wiley Periodicals, Inc.

Digital color imaging

CERN Document Server

Fernandez-Maloigne, Christine; Macaire, Ludovic

2013-01-01

This collective work identifies the latest developments in the field of the automatic processing and analysis of digital color images.For researchers and students, it represents a critical state of the art on the scientific issues raised by the various steps constituting the chain of color image processing.It covers a wide range of topics related to computational color imaging, including color filtering and segmentation, color texture characterization, color invariant for object recognition, color and motion analysis, as well as color image and video indexing and retrieval. <

Sensory Drive, Color, and Color Vision.

Science.gov (United States)

Price, Trevor D

2017-08-01

Colors often appear to differ in arbitrary ways among related species. However, a fraction of color diversity may be explained because some signals are more easily perceived in one environment rather than another. Models show that not only signals but also the perception of signals should regularly evolve in response to different environments, whether these primarily involve detection of conspecifics or detection of predators and prey. Thus, a deeper understanding of how perception of color correlates with environmental attributes should help generate more predictive models of color divergence. Here, I briefly review our understanding of color vision in vertebrates. Then I focus on opsin spectral tuning and opsin expression, two traits involved in color perception that have become amenable to study. I ask how opsin tuning is correlated with ecological differences, notably the light environment, and how this potentially affects perception of conspecific colors. Although opsin tuning appears to evolve slowly, opsin expression levels are more evolutionarily labile but have been difficult to connect to color perception. The challenge going forward will be to identify how physiological differences involved in color vision, such as opsin expression levels, translate into perceptual differences, the selection pressures that have driven those differences, and ultimately how this may drive evolution of conspecific colors.

Background matching and camouflage efficiency predict population density in four-eyed turtle (Sacalia quadriocellata).

Science.gov (United States)

Xiao, Fanrong; Yang, Canchao; Shi, Haitao; Wang, Jichao; Sun, Liang; Lin, Liu

2016-10-01

Background matching is an important way to camouflage and is widespread among animals. In the field, however, few studies have addressed background matching, and there has been no reported camouflage efficiency in freshwater turtles. Background matching and camouflage efficiency of the four-eyed turtle, Sacalia quadriocellata, among three microhabitat sections of Hezonggou stream were investigated by measuring carapace components of CIE L*a*b* (International Commission on Illumination; lightness, red/green and yellow/blue) color space, and scoring camouflage efficiency through the use of humans as predators. The results showed that the color difference (ΔE), lightness difference (ΔL(*)), and chroma difference (Δa(*)b(*)) between carapace and the substrate background in midstream were significantly lower than that upstream and downstream, indicating that the four-eyed turtle carapace color most closely matched the substrate of midstream. In line with these findings, the camouflage efficiency was the best for the turtles that inhabit midstream. These results suggest that the four-eyed turtles may enhance camouflage efficiency by selecting microhabitat that best match their carapace color. This finding may explain the high population density of the four-eyed turtle in the midstream section of Hezonggou stream. To the best of our knowledge, this study is among the first to quantify camouflage of freshwater turtles in the wild, laying the groundwork to further study the function and mechanisms of turtle camouflage. Copyright © 2016. Published by Elsevier B.V.

Comparative studies of the induction of somatic eye-color mutations in an unstable strain of Drosophila melanogaster by MMS and X-rays at different developmental stages

International Nuclear Information System (INIS)

Rasmuson, Aa.

1985-01-01

The UZ system in Drosophila melanogaster can be used as a screening system for mutagens. This survey is an attempt to correlate the size of the mutated area of the eyes with the age of the larvae at mutagen treatment. X-rays and MMS were used to give an indication of the mechanism of the instability, according to the different kinds of DNA damage induced. The results show that the mean size of red spots decreased with increasing age of larvae at treatment, while the mutation frequencies were increased because of the multiplication of the cells in the eye anlage susceptible to the mutagens. Red spots induced with MMS are smaller in size than X-ray-induced red spots, indicating a delay in the establishment of mutations from chemically-induced lesions compared to irradiation damage. White spots on the other hand were equally large in size, irrespective of inducing agent and about twice the size of the chemically-induced red spots, implying a faster and more direct action for fixation of deletions than for the production of MMS induced shifts in eye color from zeste to red. (Auth.)

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).

A comparison of facial color pattern and gazing behavior in canid species suggests gaze communication in gray wolves (Canis lupus.

Directory of Open Access Journals (Sweden)

Sayoko Ueda

Full Text Available As facial color pattern around the eyes has been suggested to serve various adaptive functions related to the gaze signal, we compared the patterns among 25 canid species, focusing on the gaze signal, to estimate the function of facial color pattern in these species. The facial color patterns of the studied species could be categorized into the following three types based on contrast indices relating to the gaze signal: A-type (both pupil position in the eye outline and eye position in the face are clear, B-type (only the eye position is clear, and C-type (both the pupil and eye position are unclear. A-type faces with light-colored irises were observed in most studied species of the wolf-like clade and some of the red fox-like clade. A-type faces tended to be observed in species living in family groups all year-round, whereas B-type faces tended to be seen in solo/pair-living species. The duration of gazing behavior during which the facial gaze-signal is displayed to the other individual was longest in gray wolves with typical A-type faces, of intermediate length in fennec foxes with typical B-type faces, and shortest in bush dogs with typical C-type faces. These results suggest that the facial color pattern of canid species is related to their gaze communication and that canids with A-type faces, especially gray wolves, use the gaze signal in conspecific communication.

Comparative Transcriptome Analysis Identifies Candidate Genes Related to Skin Color Differentiation in Red Tilapia.

Science.gov (United States)

Zhu, Wenbin; Wang, Lanmei; Dong, Zaijie; Chen, Xingting; Song, Feibiao; Liu, Nian; Yang, Hui; Fu, Jianjun

2016-08-11

Red tilapia is becoming more popular for aquaculture production in China in recent years. However, the pigmentation differentiation in genetic breeding is the main problem limiting its development of commercial red tilapia culture and the genetic basis of skin color variation is still unknown. In this study, we conducted Illumina sequencing of transcriptome on three color variety red tilapia. A total of 224,895,758 reads were generated, resulting in 160,762 assembled contigs that were used as reference contigs. The contigs of red tilapia transcriptome had hits in the range of 53.4% to 86.7% of the unique proteins of zebrafish, fugu, medaka, three-spined stickleback and tilapia. And 44,723 contigs containing 77,423 simple sequence repeats (SSRs) were identified, with 16,646 contigs containing more than one SSR. Three skin transcriptomes were compared pairwise and the results revealed that there were 148 common significantly differentially expressed unigenes and several key genes related to pigment synthesis, i.e. tyr, tyrp1, silv, sox10, slc24a5, cbs and slc7a11, were included. The results will facilitate understanding the molecular mechanisms of skin pigmentation differentiation in red tilapia and accelerate the molecular selection of the specific strain with consistent skin colors.

Color Vision in Aniridia.

Science.gov (United States)

Pedersen, Hilde R; Hagen, Lene A; Landsend, Erlend C S; Gilson, Stuart J; Utheim, Øygunn A; Utheim, Tor P; Neitz, Maureen; Baraas, Rigmor C

2018-04-01

To assess color vision and its association with retinal structure in persons with congenital aniridia. We included 36 persons with congenital aniridia (10-66 years), and 52 healthy, normal trichromatic controls (10-74 years) in the study. Color vision was assessed with Hardy-Rand-Rittler (HRR) pseudo-isochromatic plates (4th ed., 2002); Cambridge Color Test and a low-vision version of the Color Assessment and Diagnosis test (CAD-LV). Cone-opsin genes were analyzed to confirm normal versus congenital color vision deficiencies. Visual acuity and ocular media opacities were assessed. The central 30° of both eyes were imaged with the Heidelberg Spectralis OCT2 to grade the severity of foveal hypoplasia (FH, normal to complete: 0-4). Five participants with aniridia had cone opsin genes conferring deutan color vision deficiency and were excluded from further analysis. Of the 31 with aniridia and normal opsin genes, 11 made two or more red-green (RG) errors on HRR, four of whom also made yellow-blue (YB) errors; one made YB errors only. A total of 19 participants had higher CAD-LV RG thresholds, of which eight also had higher CAD-LV YB thresholds, than normal controls. In aniridia, the thresholds were higher along the RG than the YB axis, and those with a complete FH had significantly higher RG thresholds than those with mild FH (P = 0.038). Additional increase in YB threshold was associated with secondary ocular pathology. Arrested foveal formation and associated alterations in retinal processing are likely to be the primary reason for impaired red-green color vision in aniridia.

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

Science.gov (United States)

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.

Multiple nuclear and mitochondrial genotyping identifies emperors and large-eye breams (Teleostei : Lethrinidae) from New Caledonia and reveals new large-eye bream species

OpenAIRE

Borsa, Philippe; Collet, Adeline; Carassou, Laure; Ponton, Dominique; Chen, W. J.

2010-01-01

International audience; Species identification is fundamental to address questions about community ecology, biodiversity, conservation and resource management, at any life history stage. Current studies on fish larval ecology of tropical species are hampered by the lack of reliable and effective tools for identifying larvae at the species level. Emperors and large-eye breams comprise fish species from the perciform fish family Lethrinidae. They inhabit coastal and coral-reef habitats of the t...

Subretinal drusenoid deposits with increased autofluorescence in eyes with reticular pseudodrusen.

Science.gov (United States)

Lee, Mee Yon; Ham, Don-Il

2014-01-01

To characterize a variant type of drusenoid deposit with different imaging features in comparison to reticular pseudodrusen. Retrospective observational consecutive case series. Eyes showing atypical drusenoid lesions were sorted out from 257 eyes of 133 patients previously diagnosed as reticular pseudodrusen. Eyes were evaluated using color fundus photography, confocal scanning laser ophthalmoscopy, and spectral domain optical coherence tomography. A variant type of drusenoid deposits showing different imaging features from reticular pseudodrusen was found in 17 eyes of 12 patients (6.6%). The mean age of patients was 62.7 ± 11.6 years, and all patients were women. These deposits were observed as yellowish white, round to oval lesions on color photographs, located under the sensory retina and above the retinal pigment epithelium on spectral domain optical coherence tomography similar to reticular pseudodrusen. However, they were present in a smaller number as discrete lesions and showed increased autofluorescence. None of them were accompanied by late age-related macular degeneration. Subretinal drusenoid deposits are not homogeneous and can be classified into two types according to the fundus autofluorescence. Multimodal imaging tests are needed for the differential diagnosis of subretinal drusenoid deposits.

BirdsEyeView (BEV: graphical overviews of experimental data

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Zhang Lifeng

2012-09-01

Full Text Available Abstract Background Analyzing global experimental data can be tedious and time-consuming. Thus, helping biologists see results as quickly and easily as possible can facilitate biological research, and is the purpose of the software we describe. Results We present BirdsEyeView, a software system for visualizing experimental transcriptomic data using different views that users can switch among and compare. BirdsEyeView graphically maps data to three views: Cellular Map (currently a plant cell, Pathway Tree with dynamic mapping, and Gene Ontology http://www.geneontology.org Biological Processes and Molecular Functions. By displaying color-coded values for transcript levels across different views, BirdsEyeView can assist users in developing hypotheses about their experiment results. Conclusions BirdsEyeView is a software system available as a Java Webstart package for visualizing transcriptomic data in the context of different biological views to assist biologists in investigating experimental results. BirdsEyeView can be obtained from http://metnetdb.org/MetNet_BirdsEyeView.htm.

A tropical horde of counterfeit predator eyes.

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Janzen, Daniel H; Hallwachs, Winnie; Burns, John M

2010-06-29

We propose that the many different, but essentially similar, eye-like and face-like color patterns displayed by hundreds of species of tropical caterpillars and pupae-26 examples of which are displayed here from the dry, cloud, and rain forests of Area de Conservacion Guanacaste (ACG) in northwestern Costa Rica-constitute a huge and pervasive mimicry complex that is evolutionarily generated and sustained by the survival behavior of a large and multispecific array of potential predators: the insect-eating birds. We propose that these predators are variously and innately programmed to flee when abruptly confronted, at close range, with what appears to be an eye of one of their predators. Such a mimetic complex differs from various classical Batesian and Müllerian mimicry complexes of adult butterflies in that (i) the predators sustain it for the most part by innate traits rather than by avoidance behavior learned through disagreeable experiences, (ii) the more or less harmless, sessile, and largely edible mimics vastly outnumber the models, and (iii) there is no particular selection for the eye-like color pattern to closely mimic the eye or face of any particular predator of the insect-eating birds or that of any other member of this mimicry complex. Indeed, selection may not favor exact resemblance among these mimics at all. Such convergence through selection could create a superabundance of one particular false eyespot or face pattern, thereby increasing the likelihood of a bird species or guild learning to associate that pattern with harmless prey.

Troxler Fading, Eye Movements, and Retinal Ganglion Cell Properties

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Romain Bachy

2014-12-01

Full Text Available We present four movies demonstrating the effect of flicker and blur on the magnitude and speed of adaptation for foveal and peripheral vision along the three color axes that isolate retinal ganglion cells projecting to magno, parvo, and konio layers of the LGN. The demonstrations support the eye movement hypothesis for Troxler fading for brightness and color, and demonstrate the effects of flicker and blur on adaptation of each class of retinal ganglion cells.

Comparatively Studied Color Correction Methods for Color Calibration of Automated Microscopy Complex of Biomedical Specimens

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T. A. Kravtsova

2016-01-01

allow achieving values of microscopic images color correction errors below the color difference level of visibility for the human eye. The conclusion is that there is a need in development of specialized calibration target for AMS of biomedical specimens.

Gender differences in cerebral metabolism for color processing in mice: A PET/MRI Study.

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Njemanze, Philip C; Kranz, Mathias; Amend, Mario; Hauser, Jens; Wehrl, Hans; Brust, Peter

2017-01-01

Color processing is a central component of mammalian vision. Gender-related differences of color processing revealed by non-invasive functional transcranial Doppler ultrasound suggested right hemisphere pattern for blue/yellow chromatic opponency by men, and a left hemisphere pattern by women. The present study measured the accumulation of [18F]fluorodeoxyglucose ([18F]FDG) in mouse brain using small animal positron emission tomography and magnetic resonance imaging (PET/MRI) with statistical parametric mapping (SPM) during light stimulation with blue and yellow filters compared to darkness condition. PET revealed a reverse pattern relative to dark condition compared to previous human studies: Male mice presented with left visual cortex dominance for blue through the right eye, while female mice presented with right visual cortex dominance for blue through the left eye. We applied statistical parametric mapping (SPM) to examine gender differences in activated architectonic areas within the orbital and medial prefrontal cortex and related cortical and sub-cortical areas that lead to the striatum, medial thalamus and other brain areas. The metabolic connectivity of the orbital and medial prefrontal cortex evoked by blue stimulation spread through a wide range of brain structures implicated in viscerosensory and visceromotor systems in the left intra-hemispheric regions in male, but in the right-to-left inter-hemispheric regions in female mice. Color functional ocular dominance plasticity was noted in the right eye in male mice but in the left eye in female mice. This study of color processing in an animal model could be applied in the study of the role of gender differences in brain disease.

Creating experimental color harmony map

Science.gov (United States)

Chamaret, Christel; Urban, Fabrice; Lepinel, Josselin

2014-02-01

Starting in the 17th century with Newton, color harmony is a topic that did not reach a consensus on definition, representation or modeling so far. Previous work highlighted specific characteristics for color harmony on com- bination of color doublets or triplets by means of a human rating on a harmony scale. However, there were no investigation involving complex stimuli or pointing out how harmony is spatially located within a picture. The modeling of such concept as well as a reliable ground-truth would be of high value for the community, since the applications are wide and concern several communities: from psychology to computer graphics. We propose a protocol for creating color harmony maps from a controlled experiment. Through an eye-tracking protocol, we focus on the identification of disharmonious colors in pictures. The experiment was composed of a free viewing pass in order to let the observer be familiar with the content before a second pass where we asked "to search for the most disharmonious areas in the picture". Twenty-seven observers participated to the experiments that was composed of a total of 30 different stimuli. The high inter-observer agreement as well as a cross-validation confirm the validity of the proposed ground-truth.

Blue eyes in lemurs and humans: same phenotype, different genetic mechanism

DEFF Research Database (Denmark)

Bradley, Brenda J; Pedersen, Anja; Mundy, Nicholas I

2009-01-01

Almost all mammals have brown or darkly-pigmented eyes (irises), but among primates, there are some prominent blue-eyed exceptions. The blue eyes of some humans and lemurs are a striking example of convergent evolution of a rare phenotype on distant branches of the primate tree. Recent work...... on humans indicates that blue eye color is associated with, and likely caused by, a single nucleotide polymorphism (rs12913832) in an intron of the gene HERC2, which likely regulates expression of the neighboring pigmentation gene OCA2. This raises the immediate question of whether blue eyes in lemurs might...... have a similar genetic basis. We addressed this by sequencing the homologous genetic region in the blue-eyed black lemur (Eulemur macaco flavifrons; N = 4) and the closely-related black lemur (Eulemur macaco macaco; N = 4), which has brown eyes. We then compared a 166-bp segment corresponding...

Color constrains depth in da Vinci stereopsis for camouflage but not occlusion.

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Wardle, Susan G; Gillam, Barbara J

2013-12-01

Monocular regions that occur with binocular viewing of natural scenes can produce a strong perception of depth--"da Vinci stereopsis." They occur either when part of the background is occluded in one eye, or when a nearer object is camouflaged against a background surface in one eye's view. There has been some controversy over whether da Vinci depth is constrained by geometric or ecological factors. Here we show that the color of the monocular region constrains the depth perceived from camouflage, but not occlusion, as predicted by ecological considerations. Quantitative depth was found in both cases, but for camouflage only when the color of the monocular region matched the binocular background. Unlike previous reports, depth failed even when nonmatching colors satisfied conditions for perceptual transparency. We show that placing a colored line at the boundary between the binocular and monocular regions is sufficient to eliminate depth from camouflage. When both the background and the monocular region contained vertical contours that could be fused, some observers appeared to use fusion, and others da Vinci constraints, supporting the existence of a separate da Vinci mechanism. The results show that da Vinci stereopsis incorporates color constraints and is more complex than previously assumed.

Dietary Sources of Lutein and Zeaxanthin Carotenoids and Their Role in Eye Health

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Rashida Ali

2013-04-01

Full Text Available The eye is a major sensory organ that requires special care for a healthy and productive lifestyle. Numerous studies have identified lutein and zeaxanthin to be essential components for eye health. Lutein and zeaxanthin are carotenoid pigments that impart yellow or orange color to various common foods such as cantaloupe, pasta, corn, carrots, orange/yellow peppers, fish, salmon and eggs. Their role in human health, in particular the health of the eye, is well established from epidemiological, clinical and interventional studies. They constitute the main pigments found in the yellow spot of the human retina which protect the macula from damage by blue light, improve visual acuity and scavenge harmful reactive oxygen species. They have also been linked with reduced risk of age-related macular degeneration (AMD and cataracts. Research over the past decade has focused on the development of carotenoid-rich foods to boost their intake especially in the elderly population. The aim of this article is to review recent scientific evidences supporting the benefits of lutein and zexanthin in preventing the onset of two major age-related eye diseases with diets rich in these carotenoids. The review also lists major dietary sources of lutein and zeaxanthin and refers to newly developed foods, daily intake, bioavailability and physiological effects in relation to eye health. Examples of the newly developed high-lutein functional foods are also underlined.

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

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Luciene Chaves Fernandes

2003-06-01

Full Text Available As autoras propõem a utilização de lentes de contato filtrantes coloridas para melhora da discriminação de cores e do ofuscamento, em portadores de discromatopsia, na impossibilidade de montagem de filtros coloridos em óculos. Foram adaptadas lentes de contato filtrantes coloridas em dois portadores de discromatopsias, um com deutanopia e outro com acromatopsia. No primeiro, adaptou-se lente rígida filtrante, de polimetilmetacrilato (PMMA, vermelha, no olho não dominante, com o objetivo de melhorar a discriminação de cores. No segundo, colocou-se lente filtrante gelatinosa, de uso diário, de coloração marrom escuro com pupila âmbar, visando melhorar o ofuscamento. No primeiro caso, o paciente manteve inalterada a acuidade visual e também o contraste, porém demonstrou melhora na discriminação das cores ao teste de PV-16. No segundo caso, houve melhora subjetiva acentuada do ofuscamento tanto em ambiente interno, como externo. A acuidade visual e a visão de cores permaneceram sem alterações. Os achados sugerem a possibilidade de contarmos com as lentes de contato filtrantes coloridas como importante auxílio para a melhora na discriminação de cores e ofuscamento, nas discromatopsias.The authors propose the use of absorptive and colored contact lenses as an aid to color defects in making color judgments and reduce glare sensitivity in dichromatic subjects, when the use of filter in glasses is not possible. Absorptive and colored contact lenses were adapted in two dichromatic subjects, one deutanope and the other with achromatopsia. In the former, a hard absorptive, red-colored, polymethacrylate lens was adapted monocularly, in the non-dominant eye to help color judgments. In the latter, a soft absorptive, dark brown-colored lens with amber pupil was worn in both eyes to reduce glare sensitivity. Subject # 1 remained with the same visual acuity and contrast sensitivity and demonstrated a better color perception on the PV-16

Color measurement of methylene blue dye/clay mixtures and its application using economical methods

Science.gov (United States)

Milosevic, Maja; Kaludjerovic, Lazar; Logar, Mihovil

2016-04-01

Identifying the clay mineral components of clay materials by staining tests is rapid and simple, but their applicability is restricted because of the mutual interference of the common components of clay materials and difficulties in color determination. The change of color with concentration of the dye is related to the use of colorants as a field test for identifying clay minerals and has been improved over the years to assure the accuracy of the tests (Faust G. T., 1940). The problem of measurement and standardization of color may be solved by combination of colors observed in staining tests with prepared charts of color chips available in the Munsell Book of Color, published by Munsell Color Co. Under a particular set of illumination conditions, a human eye can achieve an approximate match between the color of the dyed clay sample and that of a standard color chip, even though they do have different spectral reflectance characteristics. Experiments were carried out with diffuse reflectance spectroscopy on selected clay samples (three montmorillonite, three kaolinite and one mix-layer clay samples) saturated with different concentration of methylene blue dye solution. Dominant wavelength and purity of the color was obtained on oriented dry samples and calculated by use of the I. C. I. (x, y) - diagram in the region of 400-700 nm (reflectance spectra) without MB and after saturation with different concentrations of MB solutions. Samples were carefully photographed in the natural light environment and processed with user friendly and easily accessible applications (Adobe color CC and ColorHexa encyclopedia) available for android phones or tablets. Obtained colors were compared with Munsell standard color chips, RGB and Hexa color standards. Changes in the color of clay samples in their interaction with different concentration of the applied dye together with application of economical methods can still be used as a rapid fieldwork test. Different types of clay

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.

Human attention filters for single colors

Science.gov (United States)

Sun, Peng; Chubb, Charles; Wright, Charles E.; Sperling, George

2016-01-01

The visual images in the eyes contain much more information than the brain can process. An important selection mechanism is feature-based attention (FBA). FBA is best described by attention filters that specify precisely the extent to which items containing attended features are selectively processed and the extent to which items that do not contain the attended features are attenuated. The centroid-judgment paradigm enables quick, precise measurements of such human perceptual attention filters, analogous to transmission measurements of photographic color filters. Subjects use a mouse to locate the centroid—the center of gravity—of a briefly displayed cloud of dots and receive precise feedback. A subset of dots is distinguished by some characteristic, such as a different color, and subjects judge the centroid of only the distinguished subset (e.g., dots of a particular color). The analysis efficiently determines the precise weight in the judged centroid of dots of every color in the display (i.e., the attention filter for the particular attended color in that context). We report 32 attention filters for single colors. Attention filters that discriminate one saturated hue from among seven other equiluminant distractor hues are extraordinarily selective, achieving attended/unattended weight ratios >20:1. Attention filters for selecting a color that differs in saturation or lightness from distractors are much less selective than attention filters for hue (given equal discriminability of the colors), and their filter selectivities are proportional to the discriminability distance of neighboring colors, whereas in the same range hue attention-filter selectivity is virtually independent of discriminabilty. PMID:27791040

The geometric preference subtype in ASD: identifying a consistent, early-emerging phenomenon through eye tracking.

Science.gov (United States)

Moore, Adrienne; Wozniak, Madeline; Yousef, Andrew; Barnes, Cindy Carter; Cha, Debra; Courchesne, Eric; Pierce, Karen

2018-01-01

The wide range of ability and disability in ASD creates a need for tools that parse the phenotypic heterogeneity into meaningful subtypes. Using eye tracking, our past studies revealed that when presented with social and geometric images, a subset of ASD toddlers preferred viewing geometric images, and these toddlers also had greater symptom severity than ASD toddlers with greater social attention. This study tests whether this "GeoPref test" effect would generalize across different social stimuli. Two hundred and twenty-seven toddlers (76 ASD) watched a 90-s video, the Complex Social GeoPref test, of dynamic geometric images paired with social images of children interacting and moving. Proportion of visual fixation time and number of saccades per second to both images were calculated. To allow for cross-paradigm comparisons, a subset of 126 toddlers also participated in the original GeoPref test. Measures of cognitive and social functioning (MSEL, ADOS, VABS) were collected and related to eye tracking data. To examine utility as a diagnostic indicator to detect ASD toddlers, validation statistics (e.g., sensitivity, specificity, ROC, AUC) were calculated for the Complex Social GeoPref test alone and when combined with the original GeoPref test. ASD toddlers spent a significantly greater amount of time viewing geometric images than any other diagnostic group. Fixation patterns from ASD toddlers who participated in both tests revealed a significant correlation, supporting the idea that these tests identify a phenotypically meaningful ASD subgroup. Combined use of both original and Complex Social GeoPref tests identified a subgroup of about 1 in 3 ASD toddlers from the "GeoPref" subtype (sensitivity 35%, specificity 94%, AUC 0.75.) Replicating our previous studies, more time looking at geometric images was associated with significantly greater ADOS symptom severity. Regardless of the complexity of the social images used (low in the original GeoPref test vs high in

Using support vector machines to identify literacy skills: Evidence from eye movements.

Science.gov (United States)

Lou, Ya; Liu, Yanping; Kaakinen, Johanna K; Li, Xingshan

2017-06-01

Is inferring readers' literacy skills possible by analyzing their eye movements during text reading? This study used Support Vector Machines (SVM) to analyze eye movement data from 61 undergraduate students who read a multiple-paragraph, multiple-topic expository text. Forward fixation time, first-pass rereading time, second-pass fixation time, and regression path reading time on different regions of the text were provided as features. The SVM classification algorithm assisted in distinguishing high-literacy-skilled readers from low-literacy-skilled readers with 80.3 % accuracy. Results demonstrate the effectiveness of combining eye tracking and machine learning techniques to detect readers with low literacy skills, and suggest that such approaches can be potentially used in predicting other cognitive abilities.

Comparison of corneal power, astigmatism, and wavefront aberration measurements obtained by a point-source color light-emitting diode-based topographer, a Placido-disk topographer, and a combined Placido and dual Scheimpflug device.

Science.gov (United States)

Ventura, Bruna V; Wang, Li; Ali, Shazia F; Koch, Douglas D; Weikert, Mitchell P

2015-08-01

To evaluate and compare the performance of a point-source color light-emitting diode (LED)-based topographer (color-LED) in measuring anterior corneal power and aberrations with that of a Placido-disk topographer and a combined Placido and dual Scheimpflug device. Cullen Eye Institute, Baylor College of Medicine, Houston, Texas USA. Retrospective observational case series. Normal eyes and post-refractive-surgery eyes were consecutively measured using color-LED, Placido, and dual-Scheimpflug devices. The main outcome measures were anterior corneal power, astigmatism, and higher-order aberrations (HOAs) (6.0 mm pupil), which were compared using the t test. There were no statistically significant differences in corneal power measurements in normal and post-refractive surgery eyes and in astigmatism magnitude in post-refractive surgery eyes between the color-LED device and Placido or dual Scheimpflug devices (all P > .05). In normal eyes, there were no statistically significant differences in 3rd-order coma and 4th-order spherical aberration between the color-LED and Placido devices and in HOA root mean square, 3rd-order coma, 3rd-order trefoil, 4th-order spherical aberration, and 4th-order secondary astigmatism between the color-LED and dual Scheimpflug devices (all P > .05). In post-refractive surgery eyes, the color-LED device agreed with the Placido and dual-Scheimpflug devices regarding 3rd-order coma and 4th-order spherical aberration (all P > .05). In normal and post-refractive surgery eyes, all 3 devices were comparable with respect to corneal power. The agreement in corneal aberrations varied. Drs. Wang, Koch, and Weikert are consultants to Ziemer Ophthalmic Systems AG. Dr. Koch is a consultant to Abbott Medical Optics, Inc., Alcon Surgical, Inc., and i-Optics Corp. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

When Art Moves the Eyes: A Behavioral and Eye-Tracking Study

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Massaro, Davide; Savazzi, Federica; Di Dio, Cinzia; Freedberg, David; Gallese, Vittorio; Gilli, Gabriella; Marchetti, Antonella

2012-01-01

The aim of this study was to investigate, using eye-tracking technique, the influence of bottom-up and top-down processes on visual behavior while subjects, naïve to art criticism, were presented with representational paintings. Forty-two subjects viewed color and black and white paintings (Color) categorized as dynamic or static (Dynamism) (bottom-up processes). Half of the images represented natural environments and half human subjects (Content); all stimuli were displayed under aesthetic and movement judgment conditions (Task) (top-down processes). Results on gazing behavior showed that content-related top-down processes prevailed over low-level visually-driven bottom-up processes when a human subject is represented in the painting. On the contrary, bottom-up processes, mediated by low-level visual features, particularly affected gazing behavior when looking at nature-content images. We discuss our results proposing a reconsideration of the definition of content-related top-down processes in accordance with the concept of embodied simulation in art perception. PMID:22624007

Chromatic aberration, accommodation, and color preference in asthenopia.

Science.gov (United States)

Drew, Stefanie A; Borsting, Eric; Stark, Lawrence R; Chase, Chris

2012-07-01

Asthenopia is a common problem associated with near work and reports suggest that colored lenses or overlays may be applied to reduce symptoms. In this study, we examine the relationship between eyestrain, color preferences, and function of the accommodation and vergence system. Specifically, we examine whether symptomatic observers select colors that reduce accommodative demand based on longitudinal chromatic aberration (LCA). Forty-seven undergraduate students participated in this study. Visual discomfort symptoms were assessed using the Conlon survey. A Mark 2 Intuitive Colorimeter was used to obtain optimal colored light preferences. LCA was modeled using the Chromatic Eye and spectral power density data. A comprehensive evaluation of accommodation and vergence was performed following standard procedures. A significant negative correlation (r = -0.51) was found between eyestrain symptoms and the International Commission on Illumination (CIE) v' axis of colors preferences. Additionally, a significant negative correlation (r = -0.31) was found between eyestrain symptoms and LCA accommodation. Two thirds of the participants in the high discomfort group chose colors that decreased accommodative demand. Accommodative amplitude and vergence facility also correlated with LCA, accounting for 25% of the variance. The color preferences of individuals are systematically influenced by the functioning of their accommodation and vergence systems with increased symptomatology resulting in color selections that reduce LCA accommodative stimulus demand.

Raman spectroscopy for the identification of pigments and color measurement in Dugès watercolors

Science.gov (United States)

Frausto-Reyes, C.; Ortiz-Morales, M.; Bujdud-Pérez, J. M.; Magaña-Cota, G. E.; Mejía-Falcón, R.

2009-12-01

Spectroscopic and colorimetric analysis of a representative set of Dugès watercolor paintings was performed. These paintings were the result of scientific studies carried out by the zoologist Alfredo Dugès, who recorded the fauna of the Mexican Republic between 1853 and 1910. Micro-Raman spectroscopy, with an excitation wavelength of 830 nm, and colorimetric techniques were employed in order to understand if different colors with the same hue were reproduced using the same pigments. The color coordinates of the measured areas were obtained in the CIE L* a* b* color space. Raman analysis showed that, in some cases, to reproduce colors with the same hue the pigment employed was not the same. Pigments identified in the watercolors were vermilion, carbon-based black, lead white, gamboge and chrome yellow, Prussian and ultramarine blue. Some of these pigments have been used since ancient times, others as Prussian blue, chrome yellow and synthetic ultramarine blue arrived to the market at the beginning of the 18th and 19th centuries, respectively. Furthermore, regarding the white color, instead of left the paper unpainted, lead white was detected in the eye of a bird. The green color was obtained by mixing Prussian blue with chrome yellow. The results of this work show the suitability of using Raman spectroscopy for watercolor pigment analysis and colorimetric techniques to measure the color of small areas (246 μm × 246 μm) that was the case for the lead white pigment.

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")…

Spectacle-related eye injuries, spectacle-impact performance and eye protection.

Science.gov (United States)

Hoskin, Annette K; Philip, Swetha; Dain, Stephen J; Mackey, David A

2015-05-01

The aim was to review the prevalence of spectacle-related ocular trauma and the performance of currently available spectacle materials and to identify the risk factors associated with spectacle-related ocular trauma. A literature review was conducted using Medline, Embase and Google with the keywords 'eyeglasses' OR 'spectacles' AND 'ocular injury' / 'eye injury'/ 'eye trauma' / 'ocular trauma'. Articles published prior to 1975 were excluded from this review because of advances in spectacle lens technology and Food and Drug Administration legislative changes requiring impact resistance of all prescription spectacle lenses in the United States. Six hundred and ninety-five individual ocular traumas, for which spectacles contributed to or were the main cause of injury, were identified in the literature. Eye injuries occurred when spectacles were worn in sports, in which medium- to high-impact energies were exerted from balls, racquets or bats and/or as a result of a collision with another player. Frame, lens design and product material choice were found to be associated with ocular injury, with polycarbonate lenses cited as the material of choice in the literature. International, regional and national standards for spectacle lenses had a wide range of impact requirements for prescription spectacle lenses, sports eye protection and occupational eye protection. Spectacle-related injury represents a small but preventable cause of ocular injury. With the increasing numbers of spectacle wearers and calls to spend more time outdoors to reduce myopia, spectacle wearers need to be made aware of the potential risks associated with wearing spectacles during medium- to high-risk activities. At particular risk are those prone to falls, the functionally one-eyed, those who have corneal thinning or have had previous eye surgery or injury. With increased understanding of specific risk factors, performance guidelines can be developed for prescription spectacle eye

Reward action in the initiation of smooth pursuit eye movements

OpenAIRE

Joshua, Mati; Lisberger, Stephen G.

2012-01-01

Reward has a powerful influence on motor behavior. To probe how and where reward systems alter motor behavior, we studied smooth pursuit eye movements in monkeys trained to associate the color of a visual cue with the size of the reward to be issued at the end of the target motion. When the tracking task presented two different colored targets that moved orthogonally, monkeys biased the initiation of pursuit towards the direction of motion of the target that led to larger reward. The bias was...

Retinal image quality and visual stimuli processing by simulation of partial eye cataract

Science.gov (United States)

Ozolinsh, Maris; Danilenko, Olga; Zavjalova, Varvara

2016-10-01

Visual stimuli were demonstrated on a 4.3'' mobile phone screen inside a "Virtual Reality" adapter that allowed separation of the left and right eye visual fields. Contrast of the retina image thus can be controlled by the image on the phone screen and parallel to that at appropriate geometry by the AC voltage applied to scattering PDLC cell inside the adapter. Such optical pathway separation allows to demonstrate to both eyes spatially variant images, that after visual binocular fusion acquire their characteristic indications. As visual stimuli we used grey and different color (two opponent components to vision - red-green in L*a*b* color space) spatially periodical stimuli for left and right eyes; and with spatial content that by addition or subtraction resulted as clockwise or counter clockwise slanted Gabor gratings. We performed computer modeling with numerical addition or subtraction of signals similar to processing in brain via stimuli input decomposition in luminance and color opponency components. It revealed the dependence of the perception psychophysical equilibrium point between clockwise or counter clockwise perception of summation on one eye image contrast and color saturation, and on the strength of the retinal aftereffects. Existence of a psychophysical equilibrium point in perception of summation is only in the presence of a prior adaptation to a slanted periodical grating and at the appropriate slant orientation of adaptation grating and/or at appropriate spatial grating pattern phase according to grating nods. Actual observer perception experiments when one eye images were deteriorated by simulated cataract approved the shift of mentioned psychophysical equilibrium point on the degree of artificial cataract. We analyzed also the mobile devices stimuli emission spectra paying attention to areas sensitive to macula pigments absorption spectral maxima and blue areas where the intense irradiation can cause in abnormalities in periodic melatonin

[Surgeon and eye doctor Caspar Stromayr and the ophthalmological illustrations in his "Practica copiosa" (1559)].

Science.gov (United States)

Nover, A; Kümmel, W F

1984-11-01

In 1559 Caspar Stromayr wrote a richly illustrated book about hernias and their treatment. The manuscript also includes 3 chapters of a book on ophthalmological diseases which, however, was never published. In addition, it contains 6 separate watercolor illustrations of eye diseases, though without any explanatory texts. The authors attempt to interpret these first colored pictures of eye diseases.

Grading of Age-Related Macular Degeneration: Comparison between Color Fundus Photography, Fluorescein Angiography, and Spectral Domain Optical Coherence Tomography

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Nils F. Mokwa

2013-01-01

Full Text Available Purpose. To compare color fundus photography (FP, fluorescein angiography (FA, and spectral domain optical coherence tomography (SDOCT for the detection of age-related macular degeneration (AMD, choroidal neovascularisation (CNV, and CNV activity. Methods. FPs, FAs, and SDOCT volume scans from 120 eyes of 66 AMD and control patients were randomly collected. Control eyes were required to show no AMD, but other retinal pathology was allowed. The presence of drusen, pigmentary changes, CNV, and signs for CNV activity was independently analyzed for all imaging modalities. Results. AMD was diagnosed based on FP in 75 eyes. SDOCT and FA showed sensitivity (specificity of 89% (76% and 92% (82%, respectively. CNV was present on FA in 68 eyes. Sensitivity (specificity was 78% (100% for FP and 94% (98% for SDOCT. CNV activity was detected by SDOCT or FA in 60 eyes with an agreement in 46 eyes. Sensitivity was 88% for SDOCT and 88% for FA. FP showed sensitivity of 38% and specificity of 98%. Conclusions. CNV lesions and activity may be missed by FP alone, but FP may help identifying drusen and pigmentary changes. SDOCT is highly sensitive for the detection of AMD, CNV, and CNV activity; however, it cannot fully replace FA.

Chromatic stability of acrylic resins of artificial eyes submitted to accelerated aging and polishing.

Science.gov (United States)

Goiato, Marcelo Coelho; Santos, Daniela Micheline dos; Souza, Josiene Firmino; Moreno, Amália; Pesqueira, Aldiéris Alves

2010-12-01

Esthetics and durability of materials used to fabricate artificial eyes has been an important issue since artificial eyes are essential to restore esthetics and function, protect the remaining tissues and help with patients' psychological therapy. However, these materials are submitted to degrading effects of environmental agents on the physical properties of the acrylic resin. This study assessed the color stability of acrylic resins used to fabricate sclera in three basic shades (N1, N2 and N3) when subjected to accelerated aging, mechanical and chemical polishing. Specimens of each resin were fabricated and submitted to mechanical and chemical polishing. Chromatic analysis was performed before and after accelerated aging through ultraviolet reflection spectrophotometry. All specimens revealed color alteration following polishing and accelerated aging. The resins presented statistically significant chromatic alteration (p<0.01) between the periods of 252 and 1008 h. Both polishing methods presented no significant difference between the values of color derivatives of resins.

The eye amputated - consequences of eye amputation with emphasis on clinical aspects, phantom eye syndrome and quality of life

DEFF Research Database (Denmark)

Rasmussen, Marie Louise Roed

2010-01-01

In this thesis the term eye amputation (EA) covers the removing of an eye by: evisceration, enucleation and exenteration. Amputation of an eye is most frequently the end-stage in a complicated disease, or the primary treatment in trauma and neoplasm. In 2010 the literature is extensive due...... to knowledge about types of surgery, implants and surgical technique. However, not much is known about the time past surgery. THE PURPOSE OF THE PHD THESIS WAS: To identify the number of EA, the causative diagnosis and the indication for surgical removal of the eye, the chosen surgical technique...... and to evaluate a possible change in surgical technique in Denmark from 1996 until 2003 (paper I); To describe the phantom eye syndrome and its prevalence of visual hallucinations, phantom pain and phantom sensations (paper II); To characterise the quality of phantom eye pain, including its intensity...

Post-LASIK dry eye

Science.gov (United States)

Shtein, Roni M

2011-01-01

Laser-assisted in situ keratomileusis (LASIK) is a frequently performed corneal refractive surgery with excellent refractive outcomes. The most common complication of LASIK is dry eyes, with virtually all patients developing some degree of dryness in the immediate postoperative period. Identifying preoperative dry eyes, and conscientious attention and treatment in the perioperative time period, can lead to enhanced patient satisfaction and more accurate visual outcomes. Improved understanding of the development of dry eyes after LASIK will advance our understanding of the complex pathophysiology of dry eye disease. PMID:22174730

Ocular hazards of the colors used during the festival-of-colors (Holi) in India--malachite green toxicity.

Science.gov (United States)

Velpandian, T; Saha, K; Ravi, A K; Kumari, S S; Biswas, N R; Ghose, S

2007-01-10

The objective of this study was to evaluate the nature of the colors used and their toxicity to the eye upon exposure to them during celebration of Holi (our festival-of-colors). Color powders and formulations were procured at random in and around Delhi during the festival. The green/bluish-green colors reported with the higher incidence of ocular toxicity were subjected for further evaluation. Eyewash fluid collected from the patients exposed to the colors was also subjected for analysis. This study was further extended to evaluate the corneal penetration of malachite green using goat cornea in perfusion chamber. In 16/18 color samples collected, malachite green or 4-[(4-dimethylaminophenyl)-phenyl-methyl]-N,N-dimethyl-aniline was detected at different concentrations. In the eyewash fluid of four patients, HPLC estimation confirmed the presence of malachite green at concentrations of 1.3, 0.18, 3.5 and 5.4 microg in 250 ml which was responsible for its reported toxicity. The in vitrotrans-corneal penetration studies did not show any detectable amount of malachite green in effluent fluid-in vitro tissue retention studies revealed that increasing the contact time increases tissue concentration. After 2 min of exposure, the tissue concentration was significantly higher. To conclude, malachite green was extensively used in our festival of Holi and has caused severe ocular irritation with epithelial defect upon exposure, though it did not penetrate through the cornea-further in vitro and in vivo studies are required on colors used in Holi.

Personality and Total Health Through Life Project Eye Substudy: Methodology and Baseline Retinal Features.

Science.gov (United States)

Wijngaarden, Peter Van; Keel, Stuart; Hodgson, Lauren A B; Kumar, Dinesh K; Aliahmad, Behzad; Paim, Cistiane C; Kiely, Kim M; Cherbuin, Nicolas; Anstey, Kaarin J; Dirani, Mohamed

2017-01-01

To describe the methodology and present the retinal grading findings of an older sample of australians with well-defined indices of neurocognitive function in the Personality and total Health (PATH) through life project. A cross-sectional study. Three hundred twenty-six individuals from the PatH through life project were invited to participate. Participants completed a general questionnaire and 2-field, 45-degree nonmydriatic color digital retinal photography. Photographs were graded for retinal pathology according to established protocols. Two hundred fifty-four (77.9%) subjects, aged 72 to 78 years, agreed to participate in the eye substudy. gradable images of at least 1 eye were acquired in 211 of 254 subjects (83.1%). retinal photographic screening identified 1 or more signs of pathology in 130 of the 174 subjects (74.7%) with gradable images of both eyes. a total of 45 participants (17.7%) had self-reported diabetes and diabetic retinopathy was observed in 22 (48.9%) of these participants. This well-defined sample of older australians provides a unique opportunity to interrogate associations between retinal findings, including retinal vascular geometric parameters, and indices of neurocognitive function. Copyright 2017 Asia-Pacific Academy of Ophthalmology.

ESTIMATION OF MELANIN CONTENT IN IRIS OF HUMAN EYE

Directory of Open Access Journals (Sweden)

E. A. Genina

2008-12-01

Full Text Available Based on the experimental data obtained in vivo from digital analysis of color images of human irises, the mean melanin content in human eye irises has been estimated. For registration of color images the digital camera Olympus C-5060 has been used. The images have been obtained from irises of healthy volunteers as well as from irises of patients with open-angle glaucoma. The computer program has been developed for digital analysis of the images. The result has been useful for development of novel methods and optimization of already existing ones for non-invasive glaucoma diagnostics.

Color del iris e hipoacusia en el Síndrome de Waardenburg. Pinar del Río, Cuba Color of the iris and hypoacusis in Waardenburg Syndrome. Pinar del Rio, Cuba

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Fidel Castro Pérez

2012-06-01

of review to conduct qualitative variables and chi square test X2 to measure the association of 95% of confidence. Results: about 15 individuals presented sensorineural hearing loss of different distribution and intensity, prevailing brown and blue bilateral eyes. A greater frequency of individuals with hypoacusis and blue eyes was found in association between the two variables (X2= 6,47, gl = 1; p = 0.01. Hypoacusis was greater in blue-eyed individuals (85.7% with severe or profound hypoacusis, three times superior than in the other color of eyes. Conclusions: an association between the blue color of the iris and the presence of hypoacusis along with a greater intensity of hearing loss in individuals suffering from WS was observed.

Phantom eye syndrome: types of visual hallucinations and related phenomena

DEFF Research Database (Denmark)

Roed Rasmussen, Marie Louise; Prause, Jan U; Johnson, Martin

2009-01-01

most often white or colored light, as a continuous sharp light or as moving dots. The most frequent triggers were darkness, closing of the eyes, fatigue, and psychological stress; 54% of patients had the experience more than once a week. Ten patients were so visually disturbed that it interfered...

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.

System and Method for Eye Tracking

DEFF Research Database (Denmark)

2017-01-01

A method and system for monitoring the motion of one or both eyes, includes capturing a sequence of overlapping images of a subject's face including an eye and the corresponding non-eye region; identifying a plurality of keypoints in each image; mapping corresponding keypoints in two or more images...... of the sequence; assigning the keypoints to the eye and to the corresponding non-eye region; calculating individual velocities of the corresponding keypoints in the eye and the corresponding non-eye region to obtain a distribution of velocities; extracting at least one velocity measured for the eye and at least...... one velocity measured for the corresponding non-eye region; calculating the eye-in-head velocity for the eye based upon the measured velocity for the eye and the measured velocity for the corresponding non-eye region; and calculating the eye-in-head position based upon the eye- in-head velocity....

Eye tracking social preferences

NARCIS (Netherlands)

Jiang, Ting; Potters, Jan; Funaki, Yukihiko

We hypothesize that if people are motivated by a particular social preference, then choosing in accordance with this preference will lead to an identifiable pattern of eye movements. We track eye movements while subjects make choices in simple three-person distribution experiments. We characterize

More than Just Finding Color: Strategy in Global Visual Search Is Shaped by Learned Target Probabilities

Science.gov (United States)

Williams, Carrick C.; Pollatsek, Alexander; Cave, Kyle R.; Stroud, Michael J.

2009-01-01

In 2 experiments, eye movements were examined during searches in which elements were grouped into four 9-item clusters. The target (a red or blue "T") was known in advance, and each cluster contained different numbers of target-color elements. Rather than color composition of a cluster invariantly guiding the order of search though…

Relating color working memory and color perception.

Science.gov (United States)

Allred, Sarah R; Flombaum, Jonathan I

2014-11-01

Color is the most frequently studied feature in visual working memory (VWM). Oddly, much of this work de-emphasizes perception, instead making simplifying assumptions about the inputs served to memory. We question these assumptions in light of perception research, and we identify important points of contact between perception and working memory in the case of color. Better characterization of its perceptual inputs will be crucial for elucidating the structure and function of VWM. Copyright © 2014 Elsevier Ltd. All rights reserved.

Radioactivity of neutron-irradiated cat's-eye chrysoberyls

Energy Technology Data Exchange (ETDEWEB)

Tang, S.M. E-mail: phytsm@leonis.nus.edu.sg; Tay, T.S

1999-04-02

The recent report of marketing of radioactive chrysoberyl cat's-eyes in South-East Asian markets has led us to use an indirect method to estimate the threat to health these color-enhanced gemstones may pose if worn close to skin. We determined the impurity content of several cat's-eye chrysoberyls from Indian States of Orissa and Kerala using PIXE, and calculated the radioactivity that would be generated from these impurities and the constitutional elements if a chrysoberyl was irradiated by neutrons in a nuclear reactor for color enhancement. Of all the radioactive nuclides that could be created by neutron irradiation, only four ({sup 46}Sc, {sup 51}Cr, {sup 54}Mn and {sup 59}Fe) would not have cooled down within a month after irradiation to the internationally accepted level of specific residual radioactivity of 2 nCi/g. The radioactivity of {sup 46}Sc, {sup 51}Cr and {sup 59}Fe would only fall to this safe limit after 15 months and that of {sup 54}Mn could remain above this limit for several years.

Quantitative comparison of disc rim color in optic nerve atrophy of compressive optic neuropathy and glaucomatous optic neuropathy.

Science.gov (United States)

Nakano, Eri; Hata, Masayuki; Oishi, Akio; Miyamoto, Kazuaki; Uji, Akihito; Fujimoto, Masahiro; Miyata, Manabu; Yoshimura, Nagahisa

2016-08-01

The purpose was to investigate an objective and quantitative method to estimate the redness of the optic disc neuroretinal rim, and to determine the usefulness of this method to differentiate compressive optic neuropathy (CON) from glaucomatous optic neuropathy (GON). In our study there were 126 eyes: 40 with CON, 40 with normal tension glaucoma (NTG), and 46 normal eyes (NOR). Digital color fundus photographs were assessed for the redness of disc rim color using ImageJ software. We separately measured the intensity of red, green, and blue pixels from RGB images. Three disc color indices (DCIs), which indicate the redness intensity, were calculated through existing formulas. All three DCIs of CON were significantly smaller than those of NOR (P  -6 dB), in which the extent of retinal nerve fiber layer thinning is comparable, the DCIs of mild CON were significantly smaller than those of mild NTG (P optic disc color was useful in differentiating early-stage CON from GON and NOR.

Inflammation in dry eye.

Science.gov (United States)

Stern, Michael E; Pflugfelder, Stephen C

2004-04-01

Dry eye is a condition of altered tear composition that results from a diseased or dysfunctional lacrimal functional unit. Evidence suggests that inflammation causes structural alterations and/or functional paralysis of the tear-secreting glands. Changes in tear composition resulting from lacrimal dysfunction, increased evaporation and/or poor clearance have pro-inflammatory effects on the ocular surface. This inflammation is responsible in part for the irritation symptoms, ocular surface epithelial disease, and altered corneal epithelial barrier function in dry eye. Anti-inflammatory therapies for dry eye target one or more of the inflammatory mediators/pathways that have been identified in dry eye.

The role of eye protection in work-related eye injuries.

Science.gov (United States)

Fong, L P; Taouk, Y

1995-05-01

A recent survey of general hospitals by the Victorian Injury Surveillance System found that ocular trauma represented 15% of work-related injuries. As circumstances surrounding occupational eye injuries have been poorly documented previously, their associations to occupation, industry and work-safety practices, including safety eyewear use, need to be identified to develop appropriate preventive strategies for high-risk groups. From a prospective cross-sectional survey of all eye injuries treated at the Royal Victorian Eye and Ear Hospital, work-related cases were analysed for demographic, occupational and safety eye-wear information. Hospital-based data were supplemented by information from WorkCover Authorities and Labour Force statistics to derive incidence and cost estimates. There were 9390 eye injuries during the 18-month survey period; 42% (n=3923) of total and 29% (n=52) of penetrating ocular injuries occurred at work. The most frequently injured were metal, automotive and building trades workers grinding and drilling (41% of outpatients) and hammering (53% of penetrating eye injuries). Automotive workers had the highest frequency for penetrating injuries, and most were exposed to hammering and were also the least likely to wear safety eye-wear. Eye injuries are frequent (10% of work-related injuries) and highly preventable by the correct use of safety eye-wear, a cost-effective intervention that may result in cost savings of $59 million for work-type activities in the occupational and domestic settings in Australia each year.

Salient eyes deter conspecific nest intruders in wild jackdaws (Corvus monedula).

Science.gov (United States)

Davidson, Gabrielle L; Clayton, Nicola S; Thornton, Alex

2014-02-01

Animals often respond fearfully when encountering eyes or eye-like shapes. Although gaze aversion has been documented in mammals when avoiding group-member conflict, the importance of eye coloration during interactions between conspecifics has yet to be examined in non-primate species. Jackdaws (Corvus monedula) have near-white irides, which are conspicuous against their dark feathers and visible when seen from outside the cavities where they nest. Because jackdaws compete for nest sites, their conspicuous eyes may act as a warning signal to indicate that a nest is occupied and deter intrusions by conspecifics. We tested whether jackdaws' pale irides serve as a deterrent to prospecting conspecifics by comparing prospectors' behaviour towards nest-boxes displaying images with bright eyes (BEs) only, a jackdaw face with natural BEs, or a jackdaw face with dark eyes. The jackdaw face with BEs was most effective in deterring birds from making contact with nest-boxes, whereas both BE conditions reduced the amount of time jackdaws spent in proximity to the image. We suggest BEs in jackdaws may function to prevent conspecific competitors from approaching occupied nest sites.

Method of evaluating the surface color of concrete; Concrete hyomenshoku hyoka shuho

Energy Technology Data Exchange (ETDEWEB)

Kondo, Y; Kotani, K; Imadate, F; Ito, N; Watanabe, K [Kajima Corp., Tokyo (Japan)

1995-12-20

As a part of the evaluation of landscape of civil engineering structures, a method was studied for quantitative evaluation of surface color and color hue of the exposed concrete. The surface colors of concrete structures constructed at more than one sites were measured using a colorimeter and were statistically processed. The colorimeter can measure colors by irradiating the standard light onto the surface of the object and dividing the reflection light into ingredients, lightness L and color phase a and b in the CIELAB equal color space. The L/a/b measuring data were plotted which were obtained from 2010 measuring surfaces of 49 structures at 7 construction sites. As for the surface color of concrete, it was found that ingredient L measured by the colorimeter reacts on variations of color very sensitively and agrees well with the trend of evaluation by eyes. Namely, human being senses the difference of concrete color mainly from the difference in lightness and senses the difference as the color hue. Further, using the neural network, an evaluation method was established which was the same as the human sense. 1 ref., 8 figs., 3 tabs.

Automated Detection of Glaucoma From Topographic Features of the Optic Nerve Head in Color Fundus Photographs.

Science.gov (United States)

Chakrabarty, Lipi; Joshi, Gopal Datt; Chakravarty, Arunava; Raman, Ganesh V; Krishnadas, S R; Sivaswamy, Jayanthi

2016-07-01

To describe and evaluate the performance of an automated CAD system for detection of glaucoma from color fundus photographs. Color fundus photographs of 2252 eyes from 1126 subjects were collected from 2 centers: Aravind Eye Hospital, Madurai and Coimbatore, India. The images of 1926 eyes (963 subjects) were used to train an automated image analysis-based system, which was developed to provide a decision on a given fundus image. A total of 163 subjects were clinically examined by 2 ophthalmologists independently and their diagnostic decisions were recorded. The consensus decision was defined to be the clinical reference (gold standard). Fundus images of eyes with disagreement in diagnosis were excluded from the study. The fundus images of the remaining 314 eyes (157 subjects) were presented to 4 graders and their diagnostic decisions on the same were collected. The performance of the system was evaluated on the 314 images, using the reference standard. The sensitivity and specificity of the system and 4 independent graders were determined against the clinical reference standard. The system achieved an area under receiver operating characteristic curve of 0.792 with a sensitivity of 0.716 and specificity of 0.717 at a selected threshold for the detection of glaucoma. The agreement with the clinical reference standard as determined by Cohen κ is 0.45 for the proposed system. This is comparable to that of the image-based decisions of 4 ophthalmologists. An automated system was presented for glaucoma detection from color fundus photographs. The overall evaluation results indicated that the presented system was comparable in performance to glaucoma classification by a manual grader solely based on fundus image examination.

Color surface-flow visualization of fin-generated shock wave boundary-layer interactions

Science.gov (United States)

Lu, F. K.; Settles, G. S.

1990-03-01

Kerosene-lampblack mixtures with addition of a ground colored chalk were used in an experiment on visualizing surface flows of swept shock boundary-layer interactions. The results show that contrasting colors intensify the visualization of different regions of the interaction surface, and help the eye in following the fine streaks to locate the upstream influence. The study confirms observations of the separation occurring at shock strength below accepted values. The superiority of the reported technique over the previous monochrome technique is demonstrated.

The Psychological Four-Color Mapping Problem

Science.gov (United States)

Francis, Gregory; Bias, Keri; Shive, Joshua

2010-01-01

Mathematicians have proven that four colors are sufficient to color 2-D maps so that no neighboring regions share the same color. Here we consider the psychological 4-color problem: Identifying which 4 colors should be used to make a map easy to use. We build a model of visual search for this design task and demonstrate how to apply it to the task…

Modification of the original color of the Eucalyptus grandis wood by heat treatments

Directory of Open Access Journals (Sweden)

Rosilei Aparecida Garcia

2014-09-01

Full Text Available The objective of this study was to determine the modification of original color of Eucalyptus grandis Hill ex. Maiden wood after heat-treatment. Wood samples were heat-treated under different temperatures (180, 200, 215 and 230ºC and time conditions (15 minutes, 2 and 4 hours. Color analysis were performed on the CIE L*a*b* system by using a Color Eye XTH-X-Rite 200d spectrophotometer. All heat treatments promoted an alteration of the original color of wood. Heat-treated woods presented lower L* (lightness values than untreated wood (control, characterizing the wood darkness, mainly for more severe conditions of temperature and time. Chromatic coordinates (a* and b* showed different behaviors depending on the temperature-time combination. The modification of the original color of the wood allowed the creation of new color patterns, which can add greater value to the studied wood.

Effects of bilateral eye movements on the retrieval of item, associative, and contextual information.

Science.gov (United States)

Parker, Andrew; Relph, Sarah; Dagnall, Neil

2008-01-01

Two experiments are reported that investigate the effects of saccadic bilateral eye movements on the retrieval of item, associative, and contextual information. Experiment 1 compared the effects of bilateral versus vertical versus no eye movements on tests of item recognition, followed by remember-know responses and associative recognition. Supporting previous research, bilateral eye movements enhanced item recognition by increasing the hit rate and decreasing the false alarm rate. Analysis of remember-know responses indicated that eye movement effects were accompanied by increases in remember responses. The test of associative recognition found that bilateral eye movements increased correct responses to intact pairs and decreased false alarms to rearranged pairs. Experiment 2 assessed the effects of eye movements on the recall of intrinsic (color) and extrinsic (spatial location) context. Bilateral eye movements increased correct recall for both types of context. The results are discussed within the framework of dual-process models of memory and the possible neural underpinnings of these effects are considered.

Light Vision Color

Science.gov (United States)

Valberg, Arne

2005-04-01

Light Vision Color takes a well-balanced, interdisciplinary approach to our most important sensory system. The book successfully combines basics in vision sciences with recent developments from different areas such as neuroscience, biophysics, sensory psychology and philosophy. Originally published in 1998 this edition has been extensively revised and updated to include new chapters on clinical problems and eye diseases, low vision rehabilitation and the basic molecular biology and genetics of colour vision. Takes a broad interdisciplinary approach combining basics in vision sciences with the most recent developments in the area Includes an extensive list of technical terms and explanations to encourage student understanding Successfully brings together the most important areas of the subject in to one volume

[Visual associative memory and the orientation-contingent color after-effect].

Science.gov (United States)

Maksimov, V V; Maksimov, P V

2004-01-01

The traditional explanation of the McCollough effect (ME) by selective adaptation of single detectors selective to color and orientation suffers from a number of inconsistencies: 1) the ME lasts much longer (from several days up to 3 months) than the ordinary adaptation, the decay of the effect being completely arrested by night sleep or occluding the eye for a long time; 2) the strength of the ME practically does not depend on the intensity of adapting light; and 3) a set of related pattern-contingent after-effects discovered later required for such an explanation new detectors, specific for other patterns. These properties can be explained, however, in the framework of associative memory and novelty filters. A computational model has been developed, which consists of 1) an input layer of two (left and right eyes) square matrices with two analog receptors (red and green) in each pixel, 2) an isomorphic associative neural layer, each analog neuron being synaptically connected with all receptors of both eyes, and 3) an output layer (novelty filter). The modification of synaptic efficacies conforms to the Hebb learning rule. The function of the model was examined by simulation. After a few presentations of colored gratings, the model displays the ME that is slowly destroyed by subsequent presentations of random pictures. With a sufficiently large receptor matrix, the effect lasts a thousand times longer than the period of adaptation. Continuous darkness does not change the strength of the effect. Like in real ME, the model does not display interocular transfer. The model can account for different pattern-contingent color after-effects without assuming any predetermined specific detectors. Such detectors are constructed in the course of adaptation to specific stimuli (gratings).

Study of retrobulbar hemodynamics in diabetes via color doppler ultrasound

Directory of Open Access Journals (Sweden)

Wei Chen

2014-09-01

Full Text Available AIM: To explore the changes of retrobulbar hemodynamics in diabetes via color doppler ultrasound. METHODS: Totally 80 patients(160 eyeswith eye diseases in type 2 diabetes from June 2010 to May 2013 in our hospital were enrolled as research group. By fundus photography and direct ophthalmoscopy, patients were assigned to diabetes without retinopathy group(DNR subgroup, non-proliferative diabetic retinopathy group(NPDR subgroupand proliferative diabetic retinopathy group(PDR subgroup. Of 60 healthy patients(120 eyesover the same period were chosen as control group. The doppler parameters of central retinal artery(CRA, posterior ciliary artery(PCAand ophthalmic artery(OAwere measured.RESULTS: There were significant differences on circulatory parameters of CRA, PCA and OA between both groups(PPPCONCLUSION: The monitoring of retinal blood flow and analysis of blood spectrum morphology via color doppler ultrasound can effectively evaluate the degree of diabetic retinopathy lesions, especially before DR vascular disease. Early detection can reveal the hemodynamic change pattern of DR, facilitating the prevention of diabetic eye complications and improvement of the quality of life.

Present status and task of color measurement method; Sokushiki hoho no genjo to kadai

Energy Technology Data Exchange (ETDEWEB)

Matsui, Hideyuki [Minolta Corp., Tokyo (Japan)

1999-11-01

Certainly the problem of the color of the appearance occurs, when goods are made. In case of the visual observation, it is generated by individual difference. It may become the comparison under the different condition, even if the colorimeter is used, and the problem occurs. It is observed in the combination of light source and object and eye, when the human observes the color. The fact is to digitize the condition of the visual observation of measuring the color of the object. It is necessary to fix the viewing condition, when surface state of the object is measured. (NEDO)

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.

Investigating preferences for color-shape combinations with gaze driven optimization method based on evolutionary algorithms.

Science.gov (United States)

Holmes, Tim; Zanker, Johannes M

2013-01-01

Studying aesthetic preference is notoriously difficult because it targets individual experience. Eye movements provide a rich source of behavioral measures that directly reflect subjective choice. To determine individual preferences for simple composition rules we here use fixation duration as the fitness measure in a Gaze Driven Evolutionary Algorithm (GDEA), which has been demonstrated as a tool to identify aesthetic preferences (Holmes and Zanker, 2012). In the present study, the GDEA was used to investigate the preferred combination of color and shape which have been promoted in the Bauhaus arts school. We used the same three shapes (square, circle, triangle) used by Kandinsky (1923), with the three color palette from the original experiment (A), an extended seven color palette (B), and eight different shape orientation (C). Participants were instructed to look for their preferred circle, triangle or square in displays with eight stimuli of different shapes, colors and rotations, in an attempt to test for a strong preference for red squares, yellow triangles and blue circles in such an unbiased experimental design and with an extended set of possible combinations. We Tested six participants extensively on the different conditions and found consistent preferences for color-shape combinations for individuals, but little evidence at the group level for clear color/shape preference consistent with Kandinsky's claims, apart from some weak link between yellow and triangles. Our findings suggest substantial inter-individual differences in the presence of stable individual associations of color and shapes, but also that these associations are robust within a single individual. These individual differences go some way toward challenging the claims of the universal preference for color/shape combinations proposed by Kandinsky, but also indicate that a much larger sample size would be needed to confidently reject that hypothesis. Moreover, these experiments highlight the

Fetal Eye Movements on Magnetic Resonance Imaging

Science.gov (United States)

Woitek, Ramona; Kasprian, Gregor; Lindner, Christian; Stuhr, Fritz; Weber, Michael; Schöpf, Veronika; Brugger, Peter C.; Asenbaum, Ulrika; Furtner, Julia; Bettelheim, Dieter; Seidl, Rainer; Prayer, Daniela

2013-01-01

Objectives Eye movements are the physical expression of upper fetal brainstem function. Our aim was to identify and differentiate specific types of fetal eye movement patterns using dynamic MRI sequences. Their occurrence as well as the presence of conjugated eyeball motion and consistently parallel eyeball position was systematically analyzed. Methods Dynamic SSFP sequences were acquired in 72 singleton fetuses (17–40 GW, three age groups [17–23 GW, 24–32 GW, 33–40 GW]). Fetal eye movements were evaluated according to a modified classification originally published by Birnholz (1981): Type 0: no eye movements; Type I: single transient deviations; Type Ia: fast deviation, slower reposition; Type Ib: fast deviation, fast reposition; Type II: single prolonged eye movements; Type III: complex sequences; and Type IV: nystagmoid. Results In 95.8% of fetuses, the evaluation of eye movements was possible using MRI, with a mean acquisition time of 70 seconds. Due to head motion, 4.2% of the fetuses and 20.1% of all dynamic SSFP sequences were excluded. Eye movements were observed in 45 fetuses (65.2%). Significant differences between the age groups were found for Type I (p = 0.03), Type Ia (p = 0.031), and Type IV eye movements (p = 0.033). Consistently parallel bulbs were found in 27.3–45%. Conclusions In human fetuses, different eye movement patterns can be identified and described by MRI in utero. In addition to the originally classified eye movement patterns, a novel subtype has been observed, which apparently characterizes an important step in fetal brainstem development. We evaluated, for the first time, eyeball position in fetuses. Ultimately, the assessment of fetal eye movements by MRI yields the potential to identify early signs of brainstem dysfunction, as encountered in brain malformations such as Chiari II or molar tooth malformations. PMID:24194885

Fetal eye movements on magnetic resonance imaging.

Science.gov (United States)

Woitek, Ramona; Kasprian, Gregor; Lindner, Christian; Stuhr, Fritz; Weber, Michael; Schöpf, Veronika; Brugger, Peter C; Asenbaum, Ulrika; Furtner, Julia; Bettelheim, Dieter; Seidl, Rainer; Prayer, Daniela

2013-01-01

Eye movements are the physical expression of upper fetal brainstem function. Our aim was to identify and differentiate specific types of fetal eye movement patterns using dynamic MRI sequences. Their occurrence as well as the presence of conjugated eyeball motion and consistently parallel eyeball position was systematically analyzed. Dynamic SSFP sequences were acquired in 72 singleton fetuses (17-40 GW, three age groups [17-23 GW, 24-32 GW, 33-40 GW]). Fetal eye movements were evaluated according to a modified classification originally published by Birnholz (1981): Type 0: no eye movements; Type I: single transient deviations; Type Ia: fast deviation, slower reposition; Type Ib: fast deviation, fast reposition; Type II: single prolonged eye movements; Type III: complex sequences; and Type IV: nystagmoid. In 95.8% of fetuses, the evaluation of eye movements was possible using MRI, with a mean acquisition time of 70 seconds. Due to head motion, 4.2% of the fetuses and 20.1% of all dynamic SSFP sequences were excluded. Eye movements were observed in 45 fetuses (65.2%). Significant differences between the age groups were found for Type I (p = 0.03), Type Ia (p = 0.031), and Type IV eye movements (p = 0.033). Consistently parallel bulbs were found in 27.3-45%. In human fetuses, different eye movement patterns can be identified and described by MRI in utero. In addition to the originally classified eye movement patterns, a novel subtype has been observed, which apparently characterizes an important step in fetal brainstem development. We evaluated, for the first time, eyeball position in fetuses. Ultimately, the assessment of fetal eye movements by MRI yields the potential to identify early signs of brainstem dysfunction, as encountered in brain malformations such as Chiari II or molar tooth malformations.

Outcomes in Eyes with Retinal Angiomatous Proliferation in the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT).

Science.gov (United States)

Daniel, Ebenezer; Shaffer, James; Ying, Gui-shuang; Grunwald, Juan E; Martin, Daniel F; Jaffe, Glenn J; Maguire, Maureen G

2016-03-01

To compare baseline characteristics, visual acuity (VA), and morphologic outcomes between eyes with retinal angiomatous proliferation (RAP) and all other eyes among patients with neovascular age-related macular degeneration (NVAMD) treated with anti-vascular endothelial growth factor (VEGF) drugs. Prospective cohort study within the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT). Patients with NVAMD. Reading center staff evaluated digital color fundus photographs, fluorescein angiography (FA) images, and optical coherence tomography (OCT) scans of eyes with NVAMD treated with either ranibizumab or bevacizumab over a 2-year period. Retinal angiomatous proliferation was identified by the intense intra-retinal leakage of fluorescein in combination with other associated features. Visual acuity; fluorescein leakage; scar; geographic atrophy (GA) on FA; retinal thickness, fluid, and subretinal hyperreflective material (SHRM) on OCT; and the number of intravitreal anti-VEGF injections at 1 and 2 years. Retinal angiomatous proliferation was present in 126 of 1183 (10.7%) study eyes at baseline. Mean VA improvement from baseline was greater (10.6 vs. 6.9 letters; P = 0.01) at 1 year, but similar at 2 years (7.8 vs. 6.2 letters; P = 0.34). At 1 year, eyes with RAP were more likely to have no fluid (46% vs. 26%; P treatment in CATT, eyes with RAP were less likely to have fluid, FA leakage, scar, and SHRM and more likely to have GA than eyes without RAP. Mean improvement in VA was similar at 2 years. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Color in Reference Production : The Role of Color Similarity and Color Codability

NARCIS (Netherlands)

Viethen, Jette; van Vessem, Thomas; Goudbeek, Martijn; Krahmer, Emiel

2017-01-01

It has often been observed that color is a highly preferred attribute for use in distinguishing descriptions, that is, referring expressions produced with the purpose of identifying an object within a visual scene. However, most of these observations were based on visual displays containing only

Quality indicators for eye bank.

Science.gov (United States)

Acharya, Manisha; Biswas, Saurabh; Das, Animesh; Mathur, Umang; Dave, Abhishek; Singh, Ashok; Dubey, Suneeta

2018-03-01

The aim of this study is to identify quality indicators of the eye bank and validate their effectivity. Adverse reaction rate, discard rate, protocol deviation rate, and compliance rate were defined as Quality Indicators of the eye bank. These were identified based on definition of quality that captures two dimensions - "result quality" and "process quality." The indicators were measured and tracked as part of quality assurance (QA) program of the eye bank. Regular audits were performed to validate alignment of standard operating procedures (SOP) with regulatory and surgeon acceptance standards and alignment of activities performed in the eye bank with the SOP. Prospective study of the indicators was performed by comparing their observed values over the period 2011-2016. Adverse reaction rate decreased more than 8-fold (from 0.61% to 0.07%), discard rate decreased and stabilized at 30%, protocol deviation rate decreased from 1.05% to 0.08%, and compliance rate reported by annual quality audits improved from 59% to 96% at the same time. In effect, adverse reaction rate, discard rate, and protocol deviation rate were leading indicators, and compliance rate was the trailing indicator. These indicators fulfill an important gap in available literature on QA in eye banking. There are two ways in which these findings can be meaningful. First, eye banks which are new to quality measurement can adopt these indicators. Second, eye banks which are already deeply engaged in quality improvement can test these indicators in their eye bank, thereby incorporating them widely and improving them over time.

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

Science.gov (United States)

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.

Modeling human color categorization: Color discrimination and color memory

OpenAIRE

Heskes, T.; van den Broek, Egon; Lucas, P.; Hendriks, Maria A.; Vuurpijl, L.G.; Puts, M.J.H.; Wiegerinck, W.

2003-01-01

Color matching in Content-Based Image Retrieval is done using a color space and measuring distances between colors. Such an approach yields non-intuitive results for the user. We introduce color categories (or focal colors), determine that they are valid, and use them in two experiments. The experiments conducted prove the difference between color categorization by the cognitive processes color discrimination and color memory. In addition, they yield a Color Look-Up Table, which can improve c...

Color quarks and octonions

International Nuclear Information System (INIS)

Guersey, F.

1974-01-01

A mathematical framework based on octonions is developed for the description of the color quark scheme in which quarks are unobservable, the color SU(3) is exact, and only color singlets correspond to observable hadrons. The fictitious Hilbert space in which quarks operate is taken to be a space of vectors with octonion components. This space admits as a gauge group an exact SU(3) identified with the color SU/sub C/(3). Because of the nonassociativity of the underlying algebra, nonsinglet representations of SU/sub C/(3) are unobservable, while the subspace of color singlets satisfies associativity along with conditions for observability. Octonion quark fields satisfy the commutation relations of parafermions of order 3, leading to the correct SU(6) multiplets for hadrons. (U.S.)

The genome sequence of the most widely cultivated cacao type and its use to identify candidate genes regulating pod color.

Science.gov (United States)

Motamayor, Juan C; Mockaitis, Keithanne; Schmutz, Jeremy; Haiminen, Niina; Livingstone, Donald; Cornejo, Omar; Findley, Seth D; Zheng, Ping; Utro, Filippo; Royaert, Stefan; Saski, Christopher; Jenkins, Jerry; Podicheti, Ram; Zhao, Meixia; Scheffler, Brian E; Stack, Joseph C; Feltus, Frank A; Mustiga, Guiliana M; Amores, Freddy; Phillips, Wilbert; Marelli, Jean Philippe; May, Gregory D; Shapiro, Howard; Ma, Jianxin; Bustamante, Carlos D; Schnell, Raymond J; Main, Dorrie; Gilbert, Don; Parida, Laxmi; Kuhn, David N

2013-06-03

Theobroma cacao L. cultivar Matina 1-6 belongs to the most cultivated cacao type. The availability of its genome sequence and methods for identifying genes responsible for important cacao traits will aid cacao researchers and breeders. We describe the sequencing and assembly of the genome of Theobroma cacao L. cultivar Matina 1-6. The genome of the Matina 1-6 cultivar is 445 Mbp, which is significantly larger than a sequenced Criollo cultivar, and more typical of other cultivars. The chromosome-scale assembly, version 1.1, contains 711 scaffolds covering 346.0 Mbp, with a contig N50 of 84.4 kbp, a scaffold N50 of 34.4 Mbp, and an evidence-based gene set of 29,408 loci. Version 1.1 has 10x the scaffold N50 and 4x the contig N50 as Criollo, and includes 111 Mb more anchored sequence. The version 1.1 assembly has 4.4% gap sequence, while Criollo has 10.9%. Through a combination of haplotype, association mapping and gene expression analyses, we leverage this robust reference genome to identify a promising candidate gene responsible for pod color variation. We demonstrate that green/red pod color in cacao is likely regulated by the R2R3 MYB transcription factor TcMYB113, homologs of which determine pigmentation in Rosaceae, Solanaceae, and Brassicaceae. One SNP within the target site for a highly conserved trans-acting siRNA in dicots, found within TcMYB113, seems to affect transcript levels of this gene and therefore pod color variation. We report a high-quality sequence and annotation of Theobroma cacao L. and demonstrate its utility in identifying candidate genes regulating traits.

Basal ganglia neuronal activity during scanning eye movements in Parkinson's disease.

Directory of Open Access Journals (Sweden)

Tomáš Sieger

Full Text Available The oculomotor role of the basal ganglia has been supported by extensive evidence, although their role in scanning eye movements is poorly understood. Nineteen Parkinsońs disease patients, which underwent implantation of deep brain stimulation electrodes, were investigated with simultaneous intraoperative microelectrode recordings and single channel electrooculography in a scanning eye movement task by viewing a series of colored pictures selected from the International Affective Picture System. Four patients additionally underwent a visually guided saccade task. Microelectrode recordings were analyzed selectively from the subthalamic nucleus, substantia nigra pars reticulata and from the globus pallidus by the WaveClus program which allowed for detection and sorting of individual neurons. The relationship between neuronal firing rate and eye movements was studied by crosscorrelation analysis. Out of 183 neurons that were detected, 130 were found in the subthalamic nucleus, 30 in the substantia nigra and 23 in the globus pallidus. Twenty percent of the neurons in each of these structures showed eye movement-related activity. Neurons related to scanning eye movements were mostly unrelated to the visually guided saccades. We conclude that a relatively large number of basal ganglia neurons are involved in eye motion control. Surprisingly, neurons related to scanning eye movements differed from neurons activated during saccades suggesting functional specialization and segregation of both systems for eye movement control.

Basal ganglia neuronal activity during scanning eye movements in Parkinson's disease.

Science.gov (United States)

Sieger, Tomáš; Bonnet, Cecilia; Serranová, Tereza; Wild, Jiří; Novák, Daniel; Růžička, Filip; Urgošík, Dušan; Růžička, Evžen; Gaymard, Bertrand; Jech, Robert

2013-01-01

The oculomotor role of the basal ganglia has been supported by extensive evidence, although their role in scanning eye movements is poorly understood. Nineteen Parkinsońs disease patients, which underwent implantation of deep brain stimulation electrodes, were investigated with simultaneous intraoperative microelectrode recordings and single channel electrooculography in a scanning eye movement task by viewing a series of colored pictures selected from the International Affective Picture System. Four patients additionally underwent a visually guided saccade task. Microelectrode recordings were analyzed selectively from the subthalamic nucleus, substantia nigra pars reticulata and from the globus pallidus by the WaveClus program which allowed for detection and sorting of individual neurons. The relationship between neuronal firing rate and eye movements was studied by crosscorrelation analysis. Out of 183 neurons that were detected, 130 were found in the subthalamic nucleus, 30 in the substantia nigra and 23 in the globus pallidus. Twenty percent of the neurons in each of these structures showed eye movement-related activity. Neurons related to scanning eye movements were mostly unrelated to the visually guided saccades. We conclude that a relatively large number of basal ganglia neurons are involved in eye motion control. Surprisingly, neurons related to scanning eye movements differed from neurons activated during saccades suggesting functional specialization and segregation of both systems for eye movement control.

Identification of polymorphisms in and genes and their associations with plumage colors in Asian duck breeds

Directory of Open Access Journals (Sweden)

Hasina Sultana

2018-02-01

Full Text Available Objective The aim of this study was to investigate the effect of single nucleotide polymorphisms (SNPs of the melanogenesis associated transcription factor (MITF and dopachrome tautomerase (DCT genes on plumage coloration in Asian native duck breeds. MITF encodes a protein for microphthalmia-associated transcription factor, which regulates the development and function of melanocytes for pigmentation of skin, hair, and eyes. Among the tyrosinase-related family genes, DCT is a pigment cell-specific gene that plays important roles in the melanin synthesis pathway and the expression of skin, feather, and retina color. Methods Five Asian duck varieties (black Korean native, white Korean native, commercial Peking, Nageswari, and Bangladeshi Deshi white ducks were investigated to examine the polymorphisms associated with plumage colors. Among previously identified SNPs, three synonymous SNPs and one indel of MITF and nine SNPs in exon regions of DCT were genotyped. The allele frequencies for SNPs of the black and white plumage color populations were estimated and Fisher’s exact test was conducted to assess the association between the allele frequencies of these two populations. Results Two synonymous SNPs (c.114T>G and c.147T>C and a 14-bp indel (GCTGCAAAC AGATG in intron 7 of MITF were significantly associated with the black- and white-colored breeds (pG (p.His313Arg] in DCT, was highly significantly associated (pG was significantly associated (p<0.05 with black and white color plumage in the studied duck populations. Conclusion The results of this study provide a basis for further investigations of the associations between polymorphisms and plumage color phenotypes in Asian duck breeds.

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

Directory of Open Access Journals (Sweden)

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

HIV-related ocular microangiopathic syndrome and color contrast sensitivity.

Science.gov (United States)

Geier, S A; Hammel, G; Bogner, J R; Kronawitter, U; Berninger, T; Goebel, F D

1994-06-01

Color vision deficits in patients with acquired immunodeficiency syndrome (AIDS) or human immunodeficiency virus (HIV) disease were reported, and a retinal pathogenic mechanism was proposed. The purpose of this study was to evaluate the association of color vision deficits with HIV-related retinal microangiopathy. A computer graphics system was used to measure protan, deutan, and tritan color contrast sensitivity (CCS) thresholds in 60 HIV-infected patients. Retinal microangiopathy was measured by counting the number of cotton-wool spots, and conjunctival blood-flow sludging was determined. Additional predictors were CD4+ count, age, time on aerosolized pentamidine, time on zidovudine, and Walter Reed staging. The relative influence of each predictor was calculated by stepwise multiple regression analysis (inclusion criterion; incremental P value = < 0.05) using data for the right eyes (RE). The results were validated by using data for the left eyes (LE) and both eyes (BE). The only included predictors in multiple regression analyses for the RE were number of cotton-wool spots (tritan: R = .70; deutan: R = .46; and protan: R = .58; P < .0001 for all axes) and age (tritan: increment of R [Ri] = .05, P = .002; deutan: Ri = .10, P = .004; and protan: Ri = .05, P = .002). The predictors time on zidovudine (Ri = .05, P = .002) and Walter Reed staging (Ri = .03, P = .01) were additionally included in multiple regression analysis for tritan LE. The results for deutan LE were comparable to those for the RE. In the analysis for protan LE, the only included predictor was number of cotton-wool spots. In the analyses for BE, no further predictors were included. The predictors Walter Reed staging and CD4+ count showed a significant association with all three criteria in univariate analysis. Additionally, tritan CCS was significantly associated with conjunctival blood-flow sludging. CCS deficits in patients with HIV disease are primarily associated with the number of cotton

Hormonal regulation of colour change in eyes of a cryptic fish

Directory of Open Access Journals (Sweden)

Helen Nilsson Sköld

2015-01-01

Full Text Available Colour change of the skin in lower vertebrates such as fish has been a subject of great scientific and public interest. However, colour change also takes place in eyes of fish and while an increasing amount of data indicates its importance in behaviour, very little is known about its regulation. Here, we report that both eye and skin coloration change in response to white to black background adaptation in live sand goby Pomatoschistus minutes, a bentic marine fish. Through in vitro experiments, we show that noradrenaline and melanocyte concentrating hormone (MCH treatments cause aggregation of pigment organelles in the eye chromatophores. Daylight had no aggregating effect. Combining forskolin to elevate intracellular cyclic adenosine monophosphate (cAMP with MCH resulted in complete pigment dispersal and darkening of the eyes, whereas combining prolactin, adrenocorticotrophic hormone (ACTH or melanocyte stimulating hormone (α-MSH with MCH resulted in more yellow and red eyes. ACTH and MSH also induced dispersal in the melanophores, resulting in overall darker eyes. By comparing analysis of eyes, skin and peritoneum, we conclude that the regulation pattern is similar between these different tissues in this species which is relevant for the cryptic life strategy of this species. With the exception of ACTH which resulted in most prominent melanophore pigment dispersal in the eyes, all other treatments provided similar results between tissue types. To our knowledge, this is the first study that has directly analysed hormonal regulation of physiological colour change in eyes of fish.

Visual versus Colorimetric Data Analysis for Color Determination in Resin Veneers

Directory of Open Access Journals (Sweden)

Raluca DIMA

2012-03-01

Full Text Available The color of natural teeth depends on their capacity to modify the incident light (to change the wave length of incident light. Mainly two types of observation modes are used: diffuse illumination 0% and 45%; the angles represent incidence of illumination and observation on the surface of the object whose color is determined. The patients have been properly selected to receive direct resin veneers on their frontal maxillary incisors. Visually we observed and determined color directly using natural incident light between 10 am and 16 pm, the observer was positioned away from patient so the tooth to examine was at the level of observer’s eye (incidence angles were mainly similar. Vita Easy Shade colorimeter was used to establish the color of the restoration before and after it was performed. The Expanded Visual Rating Scale for Appearance Match (EVRSAM supplied statistically comparable data as the literature; the comparison between visual and colorimetric data makes us suppose that visual color determination is a necessary but not sufficient tool for the esthetic success of any veneer restoration.

Comparison of Color Fundus Photography, Infrared Fundus Photography, and Optical Coherence Tomography in Detecting Retinal Hamartoma in Patients with Tuberous Sclerosis Complex.

Science.gov (United States)

Bai, Da-Yong; Wang, Xu; Zhao, Jun-Yang; Li, Li; Gao, Jun; Wang, Ning-Li

2016-05-20

A sensitive method is required to detect retinal hamartomas in patients with tuberous sclerosis complex (TSC). The aim of the present study was to compare the color fundus photography, infrared imaging (IFG), and optical coherence tomography (OCT) in the detection rate of retinal hamartoma in patients with TSC. This study included 11 patients (22 eyes) with TSC, who underwent color fundus photography, IFG, and spectral-domain OCT to detect retinal hamartomas. TSC1 and TSC2RESULTS: The mean age of the 11 patients was 8.0 ± 2.1 years. The mean spherical equivalent was -0.55 ± 1.42 D by autorefraction with cycloplegia. In 11 patients (22 eyes), OCT, infrared fundus photography, and color fundus photography revealed 26, 18, and 9 hamartomas, respectively. The predominant hamartoma was type I (55.6%). All the hamartomas that detected by color fundus photography or IFG can be detected by OCT. Among the methods of color fundus photography, IFG, and OCT, the OCT has higher detection rate for retinal hamartoma in TSC patients; therefore, OCT might be promising for the clinical diagnosis of TSC.

Quality indicators for eye bank

Directory of Open Access Journals (Sweden)

Manisha Acharya

2018-01-01

Full Text Available Purpose: The aim of this study is to identify quality indicators of the eye bank and validate their effectivity. Methods: Adverse reaction rate, discard rate, protocol deviation rate, and compliance rate were defined as Quality Indicators of the eye bank. These were identified based on definition of quality that captures two dimensions – “result quality” and “process quality.” The indicators were measured and tracked as part of quality assurance (QA program of the eye bank. Regular audits were performed to validate alignment of standard operating procedures (SOP with regulatory and surgeon acceptance standards and alignment of activities performed in the eye bank with the SOP. Prospective study of the indicators was performed by comparing their observed values over the period 2011–2016. Results: Adverse reaction rate decreased more than 8-fold (from 0.61% to 0.07%, discard rate decreased and stabilized at 30%, protocol deviation rate decreased from 1.05% to 0.08%, and compliance rate reported by annual quality audits improved from 59% to 96% at the same time. In effect, adverse reaction rate, discard rate, and protocol deviation rate were leading indicators, and compliance rate was the trailing indicator. Conclusion: These indicators fulfill an important gap in available literature on QA in eye banking. There are two ways in which these findings can be meaningful. First, eye banks which are new to quality measurement can adopt these indicators. Second, eye banks which are already deeply engaged in quality improvement can test these indicators in their eye bank, thereby incorporating them widely and improving them over time.

Statistic Analyses of the Color Experience According to the Age of the Observer

OpenAIRE

Hunjet, Anica; Parac-Osterman, Đurđica; Vučaj, Edita

2013-01-01

Psychological experience of color is a real state of the communication between the environment and color, and it will depend on the source of the light, angle of the view, and particular on the observer and his health condition. Hering’s theory or a theory of the opponent processes supposes that cones, which are situated in the retina of the eye, are not sensible on the three chromatic domains (areas, fields, zones) (red, green and purple-blue), but they produce a signal based on the principl...

Color vision loss in patients treated with chloroquine

Directory of Open Access Journals (Sweden)

Ventura Dora F.

2003-01-01

Full Text Available Patients that make use of chloroquine or hydroxychloroquine, drugs which are frequently administered for treatment of rheumatoid arthritis, lupus erithromatosus or malaria, may suffer alterations in color vision and in contrast sensitivity. The present work evaluates the visual function of these patients in a joint study of the University of São Paulo (USP, in São Paulo, and of the Federal University of Pará (UFPA, in Belém. Thirty two chloroquine user patients without alterations in the eye fundus exam were evaluated in São Paulo (n=10; aged 38 to 71 years; mean=55,8 years and in Belém (n=22; aged 20 to 67; mean=40 years. The prescribed accumulated chloroquine dose was 45 to 430 g (mean=213 g; sd = 152 g for the São Paulo group, and 36 to 540 g (mean=174 g; sd=183 g for the Belém group. Tests were performed monocularly with corrected eye refractive state. Color discrimination was evaluated using the Cambridge Colour Test (CCT: the color discrimination threshold was measured first in the protan, deutan and tritan axes and, in succession, three MacAdam's ellipses were determined. The patient's color vision was also evaluated with color arrangement tests: the Farnsworth-Munsell 100 Hue (FM100, the Farnsworth-Munsell D15, and the Lanthony Desaturated (D15d tests. We also measured the contrast sensitivity for black-and-white sine wave grating of twenty two patients. The results were compared with controls without ophthalmologic or neuro-ophthalmologic pathologies. Twenty four patients presented acquired dyschromatopsia. There were cases of selective loss (11 patients and of diffuse loss (13 patients. Although losses were present in the FM100 there was no correlation between the FM100 error score and the ellipse area measured by the CCT. Moreover, three patients that scored normal in the FM100, failed to reach normal threshold in the CCT. The Lanthony test was less sensitive than the other two tests, since it failed to indicate loss in about

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

Colorful ESL Test Papers And Spatial Intelligence:

Directory of Open Access Journals (Sweden)

Dennis Moradkhan

2014-11-01

Full Text Available The purpose of this research was to find out whether introducing color as an element which may appeal to spatially-intelligent candidates affects their performance on ESL grammar tests. 52 participants were given two parallel grammar tests, one in black and white and the other bearing the full spectrum of colors in the natural daylight. In order to identify the candidates with visual-spatial learning style, the participants and their teachers were asked to respond to Visual-Spatial Identifier rating scale. Based on the results, no significant relationship was found between the performance of candidates on the colorful and black and white grammar tests and their visual-spatial intelligence. It was concluded that other variables including the method of applying colors, the type and combination of colors as well as the differential impact of different colors on candidates with different cultural backgrounds needed to be addressed before any conclusions can be drawn about the application of color in language assessment.

Consistency in color parameters of a commonly used shade guide.

Science.gov (United States)

Tashkandi, Esam

2010-01-01

The use of shade guides to assess the color of natural teeth subjectively remains one of the most common means for dental shade assessment. Any variation in the color parameters of the different shade guides may lead to significant clinical implications. Particularly, since the communication between the clinic and the dental laboratory is based on using the shade guide designation. The purpose of this study was to investigate the consistency of the L∗a∗b∗ color parameters of a sample of a commonly used shade guide. The color parameters of a total of 100 VITAPAN Classical Vacuum shade guide (VITA Zahnfabrik, Bad Säckingen, Germany(were measured using a X-Rite ColorEye 7000A Spectrophotometer (Grand Rapids, Michigan, USA). Each shade guide consists of 16 tabs with different designations. Each shade tab was measured five times and the average values were calculated. The ΔE between the average L∗a∗b∗ value for each shade tab and the average of the 100 shade tabs of the same designation was calculated. Using the Student t-test analysis, no significant differences were found among the measured sample. There is a high consistency level in terms of color parameters of the measured VITAPAN Classical Vacuum shade guide sample tested.

Statistic analyses of the color experience according to the age of the observer.

Science.gov (United States)

Hunjet, Anica; Parac-Osterman, Durdica; Vucaj, Edita

2013-04-01

Psychological experience of color is a real state of the communication between the environment and color, and it will depend on the source of the light, angle of the view, and particular on the observer and his health condition. Hering's theory or a theory of the opponent processes supposes that cones, which are situated in the retina of the eye, are not sensible on the three chromatic domains (areas, fields, zones) (red, green and purple-blue), but they produce a signal based on the principle of the opposed pairs of colors. A reason of this theory depends on the fact that certain disorders of the color eyesight, which include blindness to certain colors, cause blindness to pairs of opponent colors. This paper presents a demonstration of the experience of blue and yellow tone according to the age of the observer. For the testing of the statistically significant differences in the omission in the color experience according to the color of the background we use following statistical tests: Mann-Whitnney U Test, Kruskal-Wallis ANOVA and Median test. It was proven that the differences are statistically significant in the elderly persons (older than 35 years).

Post-LASIK dry eye

OpenAIRE

Shtein, Roni M

2011-01-01

Laser-assisted in situ keratomileusis (LASIK) is a frequently performed corneal refractive surgery with excellent refractive outcomes. The most common complication of LASIK is dry eyes, with virtually all patients developing some degree of dryness in the immediate postoperative period. Identifying preoperative dry eyes, and conscientious attention and treatment in the perioperative time period, can lead to enhanced patient satisfaction and more accurate visual outcomes. Improved understanding...

The genome sequence of the most widely cultivated cacao type and its use to identify candidate genes regulating pod color

Science.gov (United States)

2013-01-01

Background Theobroma cacao L. cultivar Matina 1-6 belongs to the most cultivated cacao type. The availability of its genome sequence and methods for identifying genes responsible for important cacao traits will aid cacao researchers and breeders. Results We describe the sequencing and assembly of the genome of Theobroma cacao L. cultivar Matina 1-6. The genome of the Matina 1-6 cultivar is 445 Mbp, which is significantly larger than a sequenced Criollo cultivar, and more typical of other cultivars. The chromosome-scale assembly, version 1.1, contains 711 scaffolds covering 346.0 Mbp, with a contig N50 of 84.4 kbp, a scaffold N50 of 34.4 Mbp, and an evidence-based gene set of 29,408 loci. Version 1.1 has 10x the scaffold N50 and 4x the contig N50 as Criollo, and includes 111 Mb more anchored sequence. The version 1.1 assembly has 4.4% gap sequence, while Criollo has 10.9%. Through a combination of haplotype, association mapping and gene expression analyses, we leverage this robust reference genome to identify a promising candidate gene responsible for pod color variation. We demonstrate that green/red pod color in cacao is likely regulated by the R2R3 MYB transcription factor TcMYB113, homologs of which determine pigmentation in Rosaceae, Solanaceae, and Brassicaceae. One SNP within the target site for a highly conserved trans-acting siRNA in dicots, found within TcMYB113, seems to affect transcript levels of this gene and therefore pod color variation. Conclusions We report a high-quality sequence and annotation of Theobroma cacao L. and demonstrate its utility in identifying candidate genes regulating traits. PMID:23731509

A single gene (yes controls pigmentation of eyes and scales in Heliothis virescens

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Thomas M. Brown

2001-02-01

Full Text Available A yellow-eyed mutant was discovered in a strain of Heliothis virescens, the tobacco budworm, that already exhibited a mutation for yellow scale, y. We investigated the inheritance of these visible mutations as candidate markers for transgenesis. Yellow eye was controlled by a single, recessive, autosomal factor, the same type of inheritance previously known for y. Presence of the recombinant mutants with yellow scales with wild type eyes in test crosses indicated independent segregation of genes for these traits. The recombinant class with wild type scales and yellow eyes was completely absent and there was a corresponding increase of the double mutant parental class having yellow scales and yellow eyes. These results indicated that a single factor for yellow eye also controls yellow scales independently of y. This gene was named yes, for yellow eye and scale. We hypothesize that yes controls both eye and scale color through a deficiency in transport of pigment precursors in both the ommochrome and melanin pathways. The unlinked gene y likely controls an enzyme affecting the melanin pathway only. Both y and yes segregated independently of AceIn, acetylcholinesterase insensitivity, and sodium channel hscp, which are genes related to insecticide resistance.

Comparison of Visual Function in Older Eyes in the Earliest Stages of Age-related Macular Degeneration to Those in Normal Macular Health.

Science.gov (United States)

Owsley, Cynthia; Huisingh, Carrie; Clark, Mark E; Jackson, Gregory R; McGwin, Gerald

2016-01-01

To compare the ability of several visual functional tests in terms of the strength of their associations with the earliest phases of age-related macular degeneration (AMD), which bears on their potential to serve as functional endpoints in evaluating treatments for early AMD and prevention strategies. Eyes from adults ≥60 years old were identified as being in normal macular health or in the earliest stages of AMD (steps 2, 3 or 4) through grading of color stereo-fundus photos by an experienced grader masked to all other study variables who used the 9-step Age-Related Eye Disease Study (AREDS) classification system for AMD severity. Visual function was assessed using the following tests: best-corrected visual acuity, low luminance visual acuity, spatial contrast sensitivity, macular cone-mediated light sensitivity and rod-mediated dark adaptation. A total of 1260 eyes were tested from 640 participants; 1007 eyes were in normal macular health (defined as step 1 in AREDS system) and 253 eyes had early AMD (defined as steps 2, 3 or 4). Adjusting for age and gender, early AMD eyes had two times the odds of having delayed rod-mediated dark adaptation than eyes in normal macular health (p = 0.0019). Visual acuity, low luminance acuity, spatial contrast sensitivity and macular light sensitivity did not differ between normal eyes and early AMD eyes. Eyes in the earliest phases of AMD were two times more likely to have delayed rod-mediated dark adaptation, as assessed by the rod-intercept, as compared to older eyes in normal macular health, whereas there was no difference in early AMD versus normal eyes in tests of visual acuity, low luminance acuity, macular light sensitivity and spatial contrast sensitivity.

Determination of synthetic colorants and natural carmine in wines

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S. Virtanen

1999-09-01

Full Text Available Methods were developed for the determination of synthetic colorants and natural carmine (E120 in wines. The synthetic colorants studied were tartrazine (E102, quinoline yellow (E104, sunset yellow (E110, azo ruby (E122, amaranth (E123, ponceau 4R (E124, and erythrosine (E127. The colorants were extracted using solid-phase extraction (SPE with NH2 cartridges. The extracted colorants were then analysed by high-performance liquid chromatography (HPLC. The compounds were identified by comparing the spectrum of extract with spectra in a UV-vis spectral library of known food colorants. The detection limits in red wine ranged from 0.1 mg/l to 0.2 mg/l. Diode array detection and library search makes the method very effective in identifying forbidden colorants in wines. SPE is sufficiently effective in separating and concentrating colorants from wine. The effect of added colorants, e.g. azo ruby (E122, amaranth (E123 and tartrazine (E102 on the UV-vis spectra of red and white wines were studied. The added colorants could be identified in this way but not as accurately as by the HPLC method.

Colorful seashells: Identification of haem pathway genes associated with the synthesis of porphyrin shell color in marine snails

KAUST Repository

Williams, Suzanne T.; Lockyer, Anne E.; Dyal, Patricia; Nakano, Tomoyuki; Churchill, Celia K. C.; Speiser, Daniel I.

2017-01-01

Very little is known about the evolution of molluskan shell pigments, although Mollusca is a highly diverse, species rich, and ecologically important group of animals comprised of many brightly colored taxa. The marine snail genus Clanculus was chosen as an exceptional model for studying the evolution of shell color, first, because in Clanculus margaritarius and Clanculus pharaonius both shell and foot share similar colors and patterns; and second, because recent studies have identified the pigments, trochopuniceus (pink-red), and trochoxouthos (yellow-brown), both comprised of uroporphyrin I and uroporphyrin III, in both shell and colored foot tissue of these species. These unusual characteristics provide a rare opportunity to identify the genes involved in color production because, as the same pigments occur in the shell and colored foot tissue, the same color-related genes may be simultaneously expressed in both mantle (which produces the shell) and foot tissue. In this study, the transcriptomes of these two Clanculus species along with a third species, Calliostoma zizyphinum, were sequenced to identify genes associated with the synthesis of porphyrins. Calliostoma zizyphinum was selected as a negative control as trochopuniceus and trochoxouthos were not found to occur in this species. As expected, genes necessary for the production of uroporphyrin I and III were found in all three species, but gene expression levels were consistent with synthesis of uroporphyrins in mantle and colored foot tissue only in Clanculus. These results are relevant not only to understanding the evolution of shell pigmentation in Clanculus but also to understanding the evolution of color in other species with uroporphyrin pigmentation, including (mainly marine) mollusks soft tissues and shells, annelid and platyhelminth worms, and some bird feathers.

Colorful seashells: Identification of haem pathway genes associated with the synthesis of porphyrin shell color in marine snails

KAUST Repository

Williams, Suzanne T.

2017-10-30

Very little is known about the evolution of molluskan shell pigments, although Mollusca is a highly diverse, species rich, and ecologically important group of animals comprised of many brightly colored taxa. The marine snail genus Clanculus was chosen as an exceptional model for studying the evolution of shell color, first, because in Clanculus margaritarius and Clanculus pharaonius both shell and foot share similar colors and patterns; and second, because recent studies have identified the pigments, trochopuniceus (pink-red), and trochoxouthos (yellow-brown), both comprised of uroporphyrin I and uroporphyrin III, in both shell and colored foot tissue of these species. These unusual characteristics provide a rare opportunity to identify the genes involved in color production because, as the same pigments occur in the shell and colored foot tissue, the same color-related genes may be simultaneously expressed in both mantle (which produces the shell) and foot tissue. In this study, the transcriptomes of these two Clanculus species along with a third species, Calliostoma zizyphinum, were sequenced to identify genes associated with the synthesis of porphyrins. Calliostoma zizyphinum was selected as a negative control as trochopuniceus and trochoxouthos were not found to occur in this species. As expected, genes necessary for the production of uroporphyrin I and III were found in all three species, but gene expression levels were consistent with synthesis of uroporphyrins in mantle and colored foot tissue only in Clanculus. These results are relevant not only to understanding the evolution of shell pigmentation in Clanculus but also to understanding the evolution of color in other species with uroporphyrin pigmentation, including (mainly marine) mollusks soft tissues and shells, annelid and platyhelminth worms, and some bird feathers.

Modeling human color categorization: Color discrimination and color memory

NARCIS (Netherlands)

Heskes, T.; van den Broek, Egon; Lucas, P.; Hendriks, Maria A.; Vuurpijl, L.G.; Puts, M.J.H.; Wiegerinck, W.

2003-01-01

Color matching in Content-Based Image Retrieval is done using a color space and measuring distances between colors. Such an approach yields non-intuitive results for the user. We introduce color categories (or focal colors), determine that they are valid, and use them in two experiments. The

Improving eye care in the primary health care setting

Directory of Open Access Journals (Sweden)

M de Wet

2000-09-01

Full Text Available One of the challenges facing primary health care in South Africa is the delivery of quality eye care to all South Africans. In this regard the role of the primary health care worker, as the first point of contact, is crucial. This paper reports on the problems primary health care workers experience in providing quality eye care in Region B of the Free State. Problems identified by those involved in the study include the cumbersome referral system, the unavailability of appropriate medicine at clinics, the insufficient knowledge of primary health care workers regarding eye conditions and the lack of communication between the various eye care service providers. Suggestions to address the problems identified included more in-service training of primary health care workers regarding eye conditions, liaison with NGO’s providing eye care, decentralisation of services and the establishment of an eye care committee in the region.

Semantic guidance of eye movements in real-world scenes.

Science.gov (United States)

Hwang, Alex D; Wang, Hsueh-Cheng; Pomplun, Marc

2011-05-25

The perception of objects in our visual world is influenced by not only their low-level visual features such as shape and color, but also their high-level features such as meaning and semantic relations among them. While it has been shown that low-level features in real-world scenes guide eye movements during scene inspection and search, the influence of semantic similarity among scene objects on eye movements in such situations has not been investigated. Here we study guidance of eye movements by semantic similarity among objects during real-world scene inspection and search. By selecting scenes from the LabelMe object-annotated image database and applying latent semantic analysis (LSA) to the object labels, we generated semantic saliency maps of real-world scenes based on the semantic similarity of scene objects to the currently fixated object or the search target. An ROC analysis of these maps as predictors of subjects' gaze transitions between objects during scene inspection revealed a preference for transitions to objects that were semantically similar to the currently inspected one. Furthermore, during the course of a scene search, subjects' eye movements were progressively guided toward objects that were semantically similar to the search target. These findings demonstrate substantial semantic guidance of eye movements in real-world scenes and show its importance for understanding real-world attentional control. Copyright © 2011 Elsevier Ltd. All rights reserved.

Digital color acquisition, perception, coding and rendering

CERN Document Server

Fernandez-Maloigne, Christine; Macaire, Ludovic

2013-01-01

In this book the authors identify the basic concepts and recent advances in the acquisition, perception, coding and rendering of color. The fundamental aspects related to the science of colorimetry in relation to physiology (the human visual system) are addressed, as are constancy and color appearance. It also addresses the more technical aspects related to sensors and the color management screen. Particular attention is paid to the notion of color rendering in computer graphics. Beyond color, the authors also look at coding, compression, protection and quality of color images and videos.

Image color reduction method for color-defective observers using a color palette composed of 20 particular colors

Science.gov (United States)

Sakamoto, Takashi

2015-01-01

This study describes a color enhancement method that uses a color palette especially designed for protan and deutan defects, commonly known as red-green color blindness. The proposed color reduction method is based on a simple color mapping. Complicated computation and image processing are not required by using the proposed method, and the method can replace protan and deutan confusion (p/d-confusion) colors with protan and deutan safe (p/d-safe) colors. Color palettes for protan and deutan defects proposed by previous studies are composed of few p/d-safe colors. Thus, the colors contained in these palettes are insufficient for replacing colors in photographs. Recently, Ito et al. proposed a p/dsafe color palette composed of 20 particular colors. The author demonstrated that their p/d-safe color palette could be applied to image color reduction in photographs as a means to replace p/d-confusion colors. This study describes the results of the proposed color reduction in photographs that include typical p/d-confusion colors, which can be replaced. After the reduction process is completed, color-defective observers can distinguish these confusion colors.

A data analysis method for identifying deterministic components of stable and unstable time-delayed systems with colored noise

Energy Technology Data Exchange (ETDEWEB)

Patanarapeelert, K. [Faculty of Science, Department of Mathematics, Mahidol University, Rama VI Road, Bangkok 10400 (Thailand); Frank, T.D. [Institute for Theoretical Physics, University of Muenster, Wilhelm-Klemm-Str. 9, 48149 Muenster (Germany)]. E-mail: tdfrank@uni-muenster.de; Friedrich, R. [Institute for Theoretical Physics, University of Muenster, Wilhelm-Klemm-Str. 9, 48149 Muenster (Germany); Beek, P.J. [Faculty of Human Movement Sciences and Institute for Fundamental and Clinical Human Movement Sciences, Vrije Universiteit, Van der Boechorststraat 9, 1081 BT Amsterdam (Netherlands); Tang, I.M. [Faculty of Science, Department of Physics, Mahidol University, Rama VI Road, Bangkok 10400 (Thailand)

2006-12-18

A method is proposed to identify deterministic components of stable and unstable time-delayed systems subjected to noise sources with finite correlation times (colored noise). Both neutral and retarded delay systems are considered. For vanishing correlation times it is shown how to determine their noise amplitudes by minimizing appropriately defined Kullback measures. The method is illustrated by applying it to simulated data from stochastic time-delayed systems representing delay-induced bifurcations, postural sway and ship rolling.

Effects of polishing on surface roughness, gloss, and color of resin composites.

Science.gov (United States)

Hosoya, Yumiko; Shiraishi, Takanobu; Odatsu, Tetsuro; Nagafuji, Junichi; Kotaku, Mayumi; Miyazaki, Masashi; Powers, John M

2011-09-01

This study evaluated the effects of polishing on surface roughness, gloss, and color of regular, opaque, and enamel shades for each of three resin composites. Two-mm-thick resin disks made with Estelite Σ Quick, Clearfil Majesty, and Beautifil II were final polished with 180-, 1000-, and 3000-grit silicon carbide paper. Surface roughness, gloss, and color were measured one week after curing. Estelite Σ Quick had significantly lower roughness values and significantly higher gloss values as compared with Clearfil Majesty and Beautifil II. The effects of surface roughness and gloss on color (L*a*b*) differed among resin composites and by shade. Correlation coefficients between surface roughness and L*a*b* color factors were generally high for Clearfil Majesty, partially high (i.e., between roughness and L*) for Beautifil II, and low for Estelite Σ Quick. Correlation coefficients between gloss and L*a*b* color parameters were generally high for Beautifil II and low for Estelite Σ Quick and Clearfil Majesty. However, for all resin composites, the values of the color differences between 3000-grit and 180-grit polishing groups for all shades were imperceptible by the naked eye.

Neutral Color Semitransparent Microstructured Perovskite Solar Cells

KAUST Repository

Eperon, Giles E.

2014-01-28

Neutral-colored semitransparent solar cells are commercially desired to integrate solar cells into the windows and cladding of buildings and automotive applications. Here, we report the use of morphological control of perovskite thin films to form semitransparent planar heterojunction solar cells with neutral color and comparatively high efficiencies. We take advantage of spontaneous dewetting to create microstructured arrays of perovskite "islands", on a length-scale small enough to appear continuous to the eye yet large enough to enable unattenuated transmission of light between the islands. The islands are thick enough to absorb most visible light, and the combination of completely absorbing and completely transparent regions results in neutral transmission of light. Using these films, we fabricate thin-film solar cells with respectable power conversion efficiencies. Remarkably, we find that such discontinuous films still have good rectification behavior and relatively high open-circuit voltages due to the inherent rectification between the n- and p-type charge collection layers. Furthermore, we demonstrate the ease of "color-tinting" such microstructured perovksite solar cells with no reduction in performance, by incorporation of a dye within the hole transport medium. © 2013 American Chemical Society.

King and Eye

DEFF Research Database (Denmark)

Suwannakij, Sing

King and Eye explores the visual formation of kingship in Siam in its multifarious aspects. This dissertation identifies the leitmotifs in the dynamics between seeing the king and being seen by him, which burst forth in different eras. The visual sense has been a repository for the ontologization...... devices, most significantly the photographic and the cine cameras, but also encompassing other ocular apparatuses. The images produced through the contraptions were brought together under the royal eye at the apex, which in turn claimed its supremacy over space, time, and the vast and diverse population...

Color image quality in projection displays: a case study

Science.gov (United States)

Strand, Monica; Hardeberg, Jon Y.; Nussbaum, Peter

2005-01-01

Recently the use of projection displays has increased dramatically in different applications such as digital cinema, home theatre, and business and educational presentations. Even if the color image quality of these devices has improved significantly over the years, it is still a common situation for users of projection displays that the projected colors differ significantly from the intended ones. This study presented in this paper attempts to analyze the color image quality of a large set of projection display devices, particularly investigating the variations in color reproduction. As a case study, a set of 14 projectors (LCD and DLP technology) at Gjovik University College have been tested under four different conditions: dark and light room, with and without using an ICC-profile. To find out more about the importance of the illumination conditions in a room, and the degree of improvement when using an ICC-profile, the results from the measurements was processed and analyzed. Eye-One Beamer from GretagMacbeth was used to make the profiles. The color image quality was evaluated both visually and by color difference calculations. The results from the analysis indicated large visual and colorimetric differences between the projectors. Our DLP projectors have generally smaller color gamut than LCD projectors. The color gamuts of older projectors are significantly smaller than that of newer ones. The amount of ambient light reaching the screen is of great importance for the visual impression. If too much reflections and other ambient light reaches the screen, the projected image gets pale and has low contrast. When using a profile, the differences in colors between the projectors gets smaller and the colors appears more correct. For one device, the average ΔE*ab color difference when compared to a relative white reference was reduced from 22 to 11, for another from 13 to 6. Blue colors have the largest variations among the projection displays and makes them

Color alteration of the paint used for iris painting in ocular prostheses

Directory of Open Access Journals (Sweden)

Aline Úrsula Rocha Fernandes

2009-12-01

Full Text Available The purpose of this study was to assess color alteration of the paints used for iris painting in artificial eyes. Five disks of heat cured acrylic resin were confectioned by microwave energy for each paint analyzed, in a total of 40 specimens. Each specimen consisted of a colorless acrylic resin disk and another of equal size, of scleral white colored acrylic resin, with the painting interposed between the two disks. The specimens were submitted to an accelerated aging process in a chamber under ultraviolet radiation for 1,008 hours. To assess color variation, a reflective spectrophotometer was used. The results were statistically analyzed by ANOVA and the Tukey test (p < 0.05. All the paints underwent chromatic alteration. The oil paint presented the highest resistance to accelerated aging.

Color Fundus Photography versus Fluorescein Angiography in Identification of the Macular Center and Zone in Retinopathy of Prematurity

Science.gov (United States)

Patel, Samir N.; Klufas, Michael A.; Ryan, Michael C.; Jonas, Karyn E.; Ostmo, Susan; Martinez-Castellanos, Maria Ana; Berrocal, Audina M.; Chiang, Michael F.; Chan, R.V. Paul

2016-01-01

Purpose To examine the utility of fluorescein angiography (FA) in identification of the macular center and the diagnosis of zone in patients with retinopathy of prematurity (ROP). Design Validity and reliability analysis of diagnostic tools Methods 32 sets (16 color fundus photographs; 16 color fundus photographs paired with the corresponding FA) of wide-angle retinal images obtained from 16 eyes of eight infants with ROP were compiled on a secure web site. 9 ROP experts (3 pediatric ophthalmologists; 6 vitreoretinal surgeons) participated in the study. For each image set, experts identified the macular center and provided a diagnosis of zone. Main Outcome Measures (1) Sensitivity and specificity of zone diagnosis (2) “Computer facilitated diagnosis of zone,” based on precise measurement of the macular center, optic disc center, and peripheral ROP. Results Computer facilitated diagnosis of zone agreed with the expert’s diagnosis of zone in 28/45 (62%) cases using color fundus photographs and in 31/45 (69%) cases using FA. Mean (95% CI) sensitivity for detection of zone I by experts as compared to a consensus reference standard diagnosis when interpreting the color fundus images alone versus interpreting the color fundus photographs and FA was 47% (35.3% – 59.3%) and 61.1% (48.9% – 72.4%), respectively, (t(9) ≥ (2.063), p = 0.073). Conclusions There is a marginally significant difference in zone diagnosis when using color fundus photographs compared to using color fundus photographs and the corresponding fluorescein angiograms. There is inconsistency between traditional zone diagnosis (based on ophthalmoscopic exam and image review) compared to a computer-facilitated diagnosis of zone. PMID:25637180

Development and clinical application of a color pediatric visual acuity chart

Directory of Open Access Journals (Sweden)

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.

Color preferences are not universal.

Science.gov (United States)

Taylor, Chloe; Clifford, Alexandra; Franklin, Anna

2013-11-01

Claims of universality pervade color preference research. It has been argued that there are universal preferences for some colors over others (e.g., Eysenck, 1941), universal sex differences (e.g., Hurlbert & Ling, 2007), and universal mechanisms or dimensions that govern these preferences (e.g., Palmer & Schloss, 2010). However, there have been surprisingly few cross-cultural investigations of color preference and none from nonindustrialized societies that are relatively free from the common influence of global consumer culture. Here, we compare the color preferences of British adults to those of Himba adults who belong to a nonindustrialized culture in rural Namibia. British and Himba color preferences are found to share few characteristics, and Himba color preferences display none of the so-called "universal" patterns or sex differences. Several significant predictors of color preference are identified, such as cone-contrast between stimulus and background (Hurlbert & Ling, 2007), the valence of color-associated objects (Palmer & Schloss, 2010), and the colorfulness of the color. However, the relationship of these predictors to color preference was strikingly different for the two cultures. No one model of color preference is able to account for both British and Himba color preferences. We suggest that not only do patterns of color preference vary across individuals and groups but the underlying mechanisms and dimensions of color preference vary as well. The findings have implications for broader debate on the extent to which our perception and experience of color is culturally relative or universally constrained. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Compensation for longitudinal chromatic aberration in the eye of the firefly squid, Watasenia scintillans.

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Kröger, Ronald H H; Gislén, Anna

2004-01-01

The camera eyes of fishes and cephalopods have come forth by convergent evolution. In a variety of vertebrates capable of color vision, longitudinal chromatic aberration (LCA) of the optical system is corrected for by the exactly tuned longitudinal spherical aberration (LSA) of the crystalline lens. The LSA leads to multiple focal lengths, such that several wavelengths can be focused on the retina. We investigated whether that is also the case in the firefly squid (Watasenia scintillans), a cephalopod species that is likely to have color vision. It was found that the lens of W. scintillans is virtually free of LSA and uncorrected for LCA. However, the eye does not suffer from LCA because of a banked retina. Photoreceptors sensitive to short and long wavelengths are located at appropriate distances from the lens, such that they receive well-focused images. Such a design is an excellent solution for the firefly squid because a large area of the retina is monochromatically organized and it allows for double use of the surface area in the dichromatically organized part of the retina. However, it is not a universal solution since compensation for LCA by a banked retina requires that eye size and/or spectral separation between photopigments is small.

Influence of Surrounding Colors in the Illuminant-Color Mode on Color Constancy

Directory of Open Access Journals (Sweden)

Kazuho Fukuda

2011-05-01

Full Text Available On color constancy, we showed that brighter surrounding colors had greater influence than dim colors (Uchikawa, Kitazawa, MacLeod, Fukuda, 2010 APCV. Increasing luminance of a stimulus causes the change in appearance from the surface-color to the illuminant-color mode. However it is unknown whether the visual system considers such color appearance mode of surrounding colors to achieve color constancy. We investigated the influence of surrounding colors that appeared illuminant on color constancy. The stimulus was composed of a central test stimulus and surrounding six colors: bright and dim red, green and blue. The observers adjusted the chromaticity of the test stimulus to be appeared as an achromatic surface. The luminance balance of three bright surrounding colors was equalized with that of the optimal colors in three illuminant conditions, then, the luminance of one of the three bright colors was varied in the range beyond the critical luminance of color appearance mode transition. The results showed that increasing luminance of a bright surrounding color shifted the observers' achromatic setting toward its chromaticity, but this effect diminished for the surrounding color in the illuminant-color mode. These results suggest that the visual system considers color appearance mode of surrounding colors to accomplish color constancy.

Differences of Longitudinal Chromatic Aberration (LCA) between Eyes with Intraocular Lenses from Different Manufacturers

Science.gov (United States)

Nakajima, Masashi; Hiraoka, Takahiro; Yamamoto, Toshiya; Takagi, Seiu; Hirohara, Yoko; Oshika, Tetsuro

2016-01-01

Several researchers have studied the longitudinal chromatic aberration (LCA) of eyes implanted with an intraocular lens (IOL). We investigated the LCA of eyes implanted with yellow-colored IOLs from three different manufacturers: Alcon Inc., HOYA Corp., and AMO Inc. The number of subjects was 11, 16, and 16, respectively. The LCA of eyes implanted with SN60WF and SN60AT (Alcon Inc.), and with XY-1 (HOYA Corp.), was the same as that of phakic eyes. The LCA of eyes with ZCB00V (AMO Inc.) was smaller than that of phakic eyes. The LCA of eyes implanted with Alcon’s and HOYA’s IOLs, but not the LCA of eyes implanted with AMO’s IOLs, was positively correlated with the powers of the IOLs. We also performed simulations to verify the impacts of LCA on visual performance for 4-mm pupil diameter; the simulations were a polychromatic modulation transfer function (MTF) and a visual Strehl ratio computed on the basis of an optical transfer function (VSOTF). We concluded that the differences between the LCA of different manufacturers do not affect visual performances when some extent of higher-order aberration (HOA) exists. The smaller HOA of AMO IOLs may enhance visual performance. PMID:27258141

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.

Visidep (TM): A Three-Dimensional Imaging System For The Unaided Eye

Science.gov (United States)

McLaurin, A. Porter; Jones, Edwin R.; Cathey, LeConte

1984-05-01

The VISIDEP process for creating images in three dimensions on flat screens is suitable for photographic, electrographic and computer generated imaging systems. Procedures for generating these images vary from medium to medium due to the specific requirements of each technology. Imaging requirements for photographic and electrographic media are more directly tied to the hardware than are computer based systems. Applications of these technologies are not limited to entertainment, but have implications for training, interactive computer/video systems, medical imaging, and inspection equipment. Through minor modification the system can provide three-dimensional images with accurately measureable relationships for robotics and adds this factor for future developments in artificial intelligence. In almost any area requiring image analysis or critical review, VISIDEP provides the added advantage of three-dimensionality. All of this is readily accomplished without aids to the human eye. The system can be viewed in full color, false-color infra-red, and monochromatic modalities from any angle and is also viewable with a single eye. Thus, the potential of application for this developing system is extensive and covers the broad spectrum of human endeavor from entertainment to scientific study.

Eye tracking and nutrition label use

DEFF Research Database (Denmark)

Graham, Dan J.; Orquin, Jacob Lund; Visschers, Vivianne H.M.

2012-01-01

cameras monitoring consumer visual attention (i.e., eye tracking) has begun to identify ways in which label design could be modified to improve consumers’ ability to locate and effectively utilize nutrition information. The present paper reviews all published studies of nutrition label use that have...... utilized eye tracking methodology, identifies directions for further research in this growing field, and makes research-based recommendations for ways in which labels could be modified to improve consumers’ ability to use nutrition labels to select healthful foods....

Action Research of a Color-Coded, Onset-Rime Decoding Intervention: Examining the Effects with First Grade Students Identified as at Risk

Science.gov (United States)

Wall, Candace A.; Rafferty, Lisa A.; Camizzi, Mariya A.; Max, Caroline A.; Van Blargan, David M.

2016-01-01

Many students who struggle to obtain the alphabetic principle are at risk for being identified as having a reading disability and would benefit from additional explicit phonics instruction as a remedial measure. In this action research case study, the research team conducted two experiments to investigate the effects of a color-coded, onset-rime,…

Automatic Drusen Quantification and Risk Assessment of Age-related Macular Degeneration on Color Fundus Images

NARCIS (Netherlands)

Grinsven, M.J.J.P. van; Lechanteur, Y.T.E.; Ven, J.P.H. van de; Ginneken, B. van; Hoyng, C.B.; Theelen, T.; Sanchez, C.I.

2013-01-01

PURPOSE: To evaluate a machine learning algorithm that allows for computer aided diagnosis (CAD) of non-advanced age-related macular degeneration (AMD) by providing an accurate detection and quantification of drusen location, area and size. METHODS: Color fundus photographs of 407 eyes without AMD

Color Doppler imaging of the retrobulbar circulation in progressive glaucoma optic neuropathy.

Science.gov (United States)

Magureanu, Marineta; Stanila, Adriana; Bunescu, Liviu Valentin; Armeanu, Cristina

2016-01-01

It is known that elevated intraocular pressure (IOP) is the primary risk factor for glaucoma. Recently, more and more evidences have shown that the vascular deficit also plays an important role in the pathogenesis and progressions of glaucomatous optic neuropathy. This issue is backed up by glaucomatous optic neuropathy (GON) cases drug compensated in which the progression of the disease in one or both eyes is ascertained despite a normal and relatively constant IOP. The present study evaluated the hemodynamic parameters in the retrobulbar circulation in patients with progressive glaucomatous optic neuropathy in one eye, who received compensated medication. The hemodynamic parameters (PSV, EDV, IR) were measured by using color Doppler ultrasound and progression was evaluated by a repeated automated perimetry. The obtained values were statistically analyzed and compared with those obtained for the stable eye.

Dry eye after laser in-situ keratomileusis.

Science.gov (United States)

Raoof, Duna; Pineda, Roberto

2014-01-01

Laser-assisted in-situ keratomileusis (LASIK) is one of the most commonly performed refractive procedures with excellent visual outcomes. Dry eye syndrome is one of the most frequently seen complications after LASIK, with most patients developing at least some mild dry eye symptoms postoperatively. To achieve improved visual outcomes and greater patient satisfaction, it is essential to identify patients prone to dry eyes preoperatively, and initiate treatment early in the course. Enhanced understanding of the pathophysiology of post-LASIK dry eye will help advance our approach to its management.

EyeMusic: Making Music with the Eyes

OpenAIRE

Hornof, Anthony J.; Sato, Linda

2004-01-01

Though musical performers routinely use eye movements to communicate with each other during musical performances, very few performers or composers have used eye tracking devices to direct musical compositions and performances. EyeMusic is a system that uses eye movements as an input to electronic music compositions. The eye movements can directly control the music, or the music can respond to the eyes moving around a visual scene. EyeMusic is implemented so that any composer using established...

RED or READ: the built environment is colored

Science.gov (United States)

Smith, Dianne

2002-06-01

How important is color in the design of our built environment? Prototypes and massing models for designs are often presented in white or monochromatic combinations, irrespective of the materials incorporated and the colors that may be applied in the final constructed building, interior or object. Therefore, it is of interest to identify the way color is positioned by designers in how they go about the business of making environments. The built environment is understood by the designers and design researchers generally in one of four fields - as object, as product, as communicator, or as social domain. In addition, Franz identified four conceptions of designing held by designers - the experiential conception, the structural conception, the production conception and the retail conception. Fashion and style are often associated with color in a local context and may simply be applied to the physical environment because it is in fashion, rather than because of what it communicates more broadly. It is assumed that the integration of color in the built environment is influenced by these understandings. In order to address color's position in the design process and the importance of color in relation to space, form, and the experience of place, a selection of Queensland architects and interior designers were surveyed. The study is not conclusive, however, it does identify differences and commonalities between the participants that are of interest in light of the above issues. Explorations into environmental meaning, in addition to color theory and decorative applications, are hypothesized to be important sources of information for designers involved in the coloration of the built environment.

Collie Eye Anomaly in Switzerland.

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Walser-Reinhardt, L; Hässig, M; Spiess, B

2009-12-01

In this retrospective study, the results of 3'527 eye examinations in 6 different breeds affected with Collie Eye Anomaly (CEA) over a period of 8 years (1999 - 2007) are described. CEA was divided into three main ophthalmoscopic features, a) choroidal hypoplasia (CRH), b) CRH and coloboma and c) coloboma alone. Of the 101 Smooth Collies 8.9 % showed signs of CRH, whereas 36.9 % of Rough Collies were affected with CRH, 2.8 % with CRH and coloboma and 0.38 % with coloboma alone. Choroidal hypoplasia was present in 13.1 %, CRH and coloboma in 1.8 % and coloboma alone in 0.2 % of the Shetland Sheepdogs. Only one Australian Shepherd dog had CRH, while 0.7 % of the Border Collies were affected with CRH. None of the Nova Scotia Duck Tolling Retrievers were affected with CEA. There were no statistically significant differences in the occurrence of CEA between males and females, nor was there any relation between coat colors. Significant differences could be shown between dogs younger or older than 8 weeks at first examination. CEA was more often diagnosed in dogs younger than 8 weeks within the Rough Collie and Shetland Sheepdog.

Signalling properties of identified deep cerebellar nuclear neurons related to eye and head movements in the alert cat.

Science.gov (United States)

Gruart, A; Delgado-García, J M

1994-07-01

1. The spike activity of deep cerebellar nuclear neurons was recorded in the alert cat during spontaneous and during vestibularly and visually induced eye movements. 2. Neurons were classified according to their location in the nuclei, their antidromic activation from projection sites, their sensitivity to eye position and velocity during spontaneous eye movements, and their responses to vestibular and optokinetic stimuli. 3. Type I EPV (eye position and velocity) neurons were located mainly in the posterior part of the fastigial nucleus and activated antidromically almost exclusively from the medial longitudinal fasciculus close to the oculomotor complex. These neurons, reported here for the first time, increased their firing rate during saccades and eye fixations towards the contralateral hemifield. Their position sensitivity to eye fixations in the horizontal plane was 5.3 +/- 2.6 spikes s-1 deg-1 (mean +/- S.D.). Eye velocity sensitivity during horizontal saccades was 0.71 +/- 0.52 spikes s-1 deg-1 s-1. Variability of their firing rate during a given eye fixation was higher than that shown by abducens motoneurons. 4. Type I EPV neurons increased their firing rate during ipsilateral head rotations at 0.5 Hz with a mean phase lead over eye position of 95.3 +/- 9.5 deg. They were also activated by contralateral optokinetic stimulation at 30 deg s-1. Their sensitivity to eye position and velocity in the horizontal plane during vestibular and optokinetic stimuli yielded values similar to those obtained for spontaneous eye movements. 5. Type II neurons were located in both fastigial and dentate nuclei and were activated antidromically from the restiform body, the medial longitudinal fasciculus close to the oculomotor complex, the red nucleus and the pontine nuclei. Type II neurons were not related to spontaneous eye movements. These neurons increased their firing rate in response to contralateral head rotation and during ipsilateral optokinetic stimulation, and

Processing of Color Words Activates Color Representations

Science.gov (United States)

Richter, Tobias; Zwaan, Rolf A.

2009-01-01

Two experiments were conducted to investigate whether color representations are routinely activated when color words are processed. Congruency effects of colors and color words were observed in both directions. Lexical decisions on color words were faster when preceding colors matched the color named by the word. Color-discrimination responses…

Prevalence of dry eye syndrome and diabetic retinopathy in type 2 diabetic patients

Directory of Open Access Journals (Sweden)

Afkhami-Ardekani Mohammad

2008-06-01

Full Text Available Abstract Background This study was performed to assess the prevalence of dry eye syndrome and diabetic retinopathy (DR in type 2 diabetic patients and their contributing factors. Methods 199 type 2 diabetic patients referred to Yazd Diabetes Research Center were consecutively selected. All Subjects were assessed by questionnaire about other diseases and drugs. Dry eye syndrome was assessed with Tear break up time tests and Schirmer. All the subjects underwent indirect ophthalmoscopy and retinal color photography. DR was graded according to early Treatment Diabetic Retinopathy (ETDRS criteria. Results Of 199 subjects, 108 patients (54.3% suffer from dry eye syndrome. Although dry eye syndrome was more common in older and female patients, this association was not significant. But there was significantly association between dry eye syndrome and duration of diabetes (P = 0.01. Dry eye syndrome was more frequent in diabetic patients with DR (P = 0.02. DR was found in 140 patients (70.35%, which included 34 patients (17.1% with mild non proliferative DR (NPDR, 34 patients (17.1% with moderate NPDR, 22 patients (11.1% with severe NPDR and 25 patients (25.1% with proliferative DR (PDR. There were significant relation between age, sex and duration of diabetes and DR. Conclusion In this study the prevalence of dry eye syndrome was 54.3%. Diabetes and dry eyes appear to have a common association. Further studies need to be undertaken to establish an etiologic relationship. However, examination for dry eye should be an integral part of the assessment of diabetic eye disease.

EyeAR: Refocusable Augmented Reality Content through Eye Measurements

Directory of Open Access Journals (Sweden)

Damien Constantine Rompapas

2017-09-01

Full Text Available Augmented Reality (AR superimposes computer graphics (CG onto a user’s view of the real world. A key quality problem in this field is to achieve coherence between reality and CG when the user’s eyes refocus or change pupil size. We designed and evaluated a display that improves coherence by measuring the user’s eye state and continuously adapting CG accordingly. Our tabletop prototype emulates an Optical See-Through Head-Mounted Display, a common AR display device. In our evaluation, participants observed three pillars at different depths. We then challenged them to identify a virtual pillar among the three while freely refocusing their eyes. Results show that our design significantly improved realism. Compared to Light Field Displays, our design aims to simplify display-optics while providing similar quality. We could only partially achieve this goal. We discuss the lessons we learned and how we plan to overcome the remaining challenges. The experimental protocol from our evaluation is useful for display developers as it can be used to measure the coherence of a display.

Color categories and color appearance

Science.gov (United States)

Webster, Michael A.; Kay, Paul

2011-01-01

We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue–green boundary, to test whether chromatic differences across the boundary were perceptually exaggerated. This task did not require overt judgments of the perceived colors, and the tendency to group showed only a weak and inconsistent categorical bias. In a second case, we analyzed results from two prior studies of hue scaling of chromatic stimuli (De Valois, De Valois, Switkes, & Mahon, 1997; Malkoc, Kay, & Webster, 2005), to test whether color appearance changed more rapidly around the blue–green boundary. In this task observers directly judge the perceived color of the stimuli and these judgments tended to show much stronger categorical effects. The differences between these tasks could arise either because different signals mediate color grouping and color appearance, or because linguistic categories might differentially intrude on the response to color and/or on the perception of color. Our results suggest that the interaction between language and color processing may be highly dependent on the specific task and cognitive demands and strategies of the observer, and also highlight pronounced individual differences in the tendency to exhibit categorical responses. PMID:22176751

Choroid metastasis of papillary thyroid carcinoma. Color doppler ultrasound study

International Nuclear Information System (INIS)

Ganado, T.; Torre, S. de la; Contreras, E.; Hernandez, J.

1997-01-01

The most common causes of intraocular metastases are breast and lung cancers, although many other neoplasms can metastasize to the eye. Most of the metastases are located in the posterior pole and the choroid is more often involved than the retina. We present a case of a choroidal metastasis from a papillary carcinoma of the thyroid, associated with a massive subretinal hemorrhage. Findings with color Doppler ultrasound are emphasized. (Author) 9 refs

Searching for the prototypic eye genetic network: Sine oculis is essential for eye regeneration in planarians

Science.gov (United States)

Pineda, D.; Gonzalez, J.; Callaerts, P.; Ikeo, K.; Gehring, W. J.; Salo, E.

2000-01-01

We have identified a sine oculis gene in the planarian Girardia tigrina (Platyhelminthes; Turbellaria; Tricladida). The planarian sine oculis gene (Gtso) encodes a protein with a sine oculis (Six) domain and a homeodomain that shares significant sequence similarity with so proteins assigned to the Six-2 gene family. Gtso is expressed as a single transcript in both regenerating and fully developed eyes. Whole-mount in situ hybridization studies show exclusive expression in photoreceptor cells. Loss of function of Gtso by RNA interference during planarian regeneration inhibits eye regeneration completely. Gtso is also essential for maintenance of the differentiated state of photoreceptor cells. These results, combined with the previously demonstrated expression of Pax-6 in planarian eyes, suggest that the same basic gene regulatory circuit required for eye development in Drosophila and mouse is used in the prototypic eye spots of platyhelminthes and, therefore, is truly conserved during evolution. PMID:10781056

A bioinspired color-changing polystyrene microarray as a rapid qualitative sensor for methanol and ethanol

International Nuclear Information System (INIS)

Kuo, Wen-Kai; Weng, Hsueh-Ping; Hsu, Jyun-Jheng; Yu, Hsin Her

2016-01-01

Polystyrene (PS) microspheres were synthesized by emulsifier-free emulsion polymerization and arranged in an array of closely packed, opal-like photonic crystals by slow self-assembly through dip-coating. This periodic array of PS microspheres was then employed as a rapid qualitative sensor for methanol and ethanol. Both solvents could be detected rapidly based on the routes of their reflection coordinates in the chromaticity diagram or directly by the naked eye on the basis of the change in color within 1 min once a solvent sample had been placed on the PS photochromic sensor. This opal-like PS sensor can thus not only be employed as a rapid sensor for methanol and ethanol but can also be used as a powerful tool for the fast screening of illicit drugs and toxic chemicals during forensic investigations. - Highlights: • Opal-like array of polystyrene (PS) microspheres is synthesized by self-assembly. • This periodic PS array is used as a rapid sensor for methanol and ethanol. • Solvents are detected by routes of reflection coordinates in chromaticity diagram. • They are also detected directly by naked eye based on change in color of sensor. • The color change is irreversible for methanol but reversible for ethanol.

A bioinspired color-changing polystyrene microarray as a rapid qualitative sensor for methanol and ethanol

Energy Technology Data Exchange (ETDEWEB)

Kuo, Wen-Kai, E-mail: wkkuo@nfu.edu.tw [Graduate Institute of Electro-Optical and Materials Science, National Formosa University, 64 Wenhua Road, Huwei, Yunlin 63208, Taiwan (China); Weng, Hsueh-Ping, E-mail: sherry.weng7949@gmail.com [Graduate Institute of Electro-Optical and Materials Science, National Formosa University, 64 Wenhua Road, Huwei, Yunlin 63208, Taiwan (China); Hsu, Jyun-Jheng, E-mail: k88520x@gmail.com [Graduate Institute of Electro-Optical and Materials Science, National Formosa University, 64 Wenhua Road, Huwei, Yunlin 63208, Taiwan (China); Yu, Hsin Her, E-mail: hhyu@nfu.edu.tw [Department of Biotechnology, National Formosa University, 64 Wenhua Road, Huwei, Yunlin 63208, Taiwan (China)

2016-04-15

Polystyrene (PS) microspheres were synthesized by emulsifier-free emulsion polymerization and arranged in an array of closely packed, opal-like photonic crystals by slow self-assembly through dip-coating. This periodic array of PS microspheres was then employed as a rapid qualitative sensor for methanol and ethanol. Both solvents could be detected rapidly based on the routes of their reflection coordinates in the chromaticity diagram or directly by the naked eye on the basis of the change in color within 1 min once a solvent sample had been placed on the PS photochromic sensor. This opal-like PS sensor can thus not only be employed as a rapid sensor for methanol and ethanol but can also be used as a powerful tool for the fast screening of illicit drugs and toxic chemicals during forensic investigations. - Highlights: • Opal-like array of polystyrene (PS) microspheres is synthesized by self-assembly. • This periodic PS array is used as a rapid sensor for methanol and ethanol. • Solvents are detected by routes of reflection coordinates in chromaticity diagram. • They are also detected directly by naked eye based on change in color of sensor. • The color change is irreversible for methanol but reversible for ethanol.

Connecting eye to eye

DEFF Research Database (Denmark)

Dau, Susanne; Rask, Anders Bindslev

2017-01-01

Computer Supported Collaborative Learning (CSCL) is used a frame for supporting online and blended learning in educations. The online communication and collaboration are afforded by the social collaboration. However, the social collaboration is based on the establishment of direct eye contact...... (Khalid, Deska & Hugenberg, 2016), but direct eye contact is challenged by the position of the digital devices and thus CSCL. Lack of eye contact is the chief contributor to the negative effects of online disinhibition (Lapidot-Lefler & Barak, 2012) and the problem is the location of the web camera...... at the computer. Eye contact is challenged by the displacement between the senders´ and receivers´ focus on the screen picture and the camera's location at the top or bottom of screens on all digital devices. The aim of this paper is accordingly to investigate the influence of the displacement in eye contact...

A Deep Learning Algorithm for Prediction of Age-Related Eye Disease Study Severity Scale for Age-Related Macular Degeneration from Color Fundus Photography.

Science.gov (United States)

Grassmann, Felix; Mengelkamp, Judith; Brandl, Caroline; Harsch, Sebastian; Zimmermann, Martina E; Linkohr, Birgit; Peters, Annette; Heid, Iris M; Palm, Christoph; Weber, Bernhard H F

2018-04-10

Age-related macular degeneration (AMD) is a common threat to vision. While classification of disease stages is critical to understanding disease risk and progression, several systems based on color fundus photographs are known. Most of these require in-depth and time-consuming analysis of fundus images. Herein, we present an automated computer-based classification algorithm. Algorithm development for AMD classification based on a large collection of color fundus images. Validation is performed on a cross-sectional, population-based study. We included 120 656 manually graded color fundus images from 3654 Age-Related Eye Disease Study (AREDS) participants. AREDS participants were >55 years of age, and non-AMD sight-threatening diseases were excluded at recruitment. In addition, performance of our algorithm was evaluated in 5555 fundus images from the population-based Kooperative Gesundheitsforschung in der Region Augsburg (KORA; Cooperative Health Research in the Region of Augsburg) study. We defined 13 classes (9 AREDS steps, 3 late AMD stages, and 1 for ungradable images) and trained several convolution deep learning architectures. An ensemble of network architectures improved prediction accuracy. An independent dataset was used to evaluate the performance of our algorithm in a population-based study. κ Statistics and accuracy to evaluate the concordance between predicted and expert human grader classification. A network ensemble of 6 different neural net architectures predicted the 13 classes in the AREDS test set with a quadratic weighted κ of 92% (95% confidence interval, 89%-92%) and an overall accuracy of 63.3%. In the independent KORA dataset, images wrongly classified as AMD were mainly the result of a macular reflex observed in young individuals. By restricting the KORA analysis to individuals >55 years of age and prior exclusion of other retinopathies, the weighted and unweighted κ increased to 50% and 63%, respectively. Importantly, the algorithm

Characteristics of color memory for natural scenes

Science.gov (United States)

Amano, Kinjiro; Uchikawa, Keiji; Kuriki, Ichiro

2002-08-01

To study the characteristics of color memory for natural images, a memory-identification task was performed with differing color contrasts; three of the contrasts were defined by chromatic and luminance components of the image, and the others were defined with respect to the categorical colors. After observing a series of pictures successively, subjects identified the pictures using a confidence rating. Detection of increased contrasts tended to be harder than detection of decreased contrasts, suggesting that the chromaticness of pictures is enhanced in memory. Detecting changes within each color category was more difficult than across the categories. A multiple mechanism that processes color differences and categorical colors is briefly considered. 2002 Optical Society of America

Eye Allergies

Science.gov (United States)

... Español Eye Health / Eye Health A-Z Eye Allergies Sections What Are Eye Allergies? Eye Allergy Symptoms ... allergy diagnosis Eye allergy treatment What Are Eye Allergies? Leer en Español: ¿Qué son las alergias de ...

Object color affects identification and repetition priming.

Science.gov (United States)

Uttl, Bob; Graf, Peter; Santacruz, Pilar

2006-10-01

We investigated the influence of color on the identification of both non-studied and studied objects. Participants studied black and white and color photos of common objects and memory was assessed with an identification test. Consistent with our meta-analysis of prior research, we found that objects were easier to identify from color than from black and white photos. We also found substantial priming in all conditions, and study-to-test changes in an object's color reduced the magnitude of priming. Color-specific priming effects were large for color-complex objects, but minimal for color-simple objects. The pattern and magnitude of priming effects was not influenced either by the extent to which an object always appears in the same color (i.e., whether a color is symptomatic of an object) or by the object's origin (natural versus fabricated). We discuss the implications of our findings for theoretical accounts of object perception and repetition priming.

METAPHOR OF COLORS IN INDONESIAN

Directory of Open Access Journals (Sweden)

I Dewa Putu Wijana

2015-06-01

Full Text Available This brief article deals with the use of Indonesian words referring to colors for creating metaphorical expressions. All data presented are collected from various sources, such as Kamus Besar Bahasa Indonesia (Indonesian Standard Dictionary, and added with data obtained from Oxford Advanced Leaner’s Dictionary, Indonesian proverb book, encyclopedia, terminology collection book, poetry anthology, song lyrics, and data of the author’s own creation as an Indonesian native speaker. Set aside from their literal meanings, the metaphorically used color words are collected and classified into two categories, i.e. achromatic and chromatic colors. Then, their universalities are determined by comparing them with English color metaphors. Finally the existence of specific Indonesian color metaphors are identified by correlating them with extra linguistic factors, such as environment, history, religion, politic and other socio cultural activities. A careful analysis on the data shows that there is nearly no significant difference in metaphorical uses of achromatic colors in English and Indonesian. However, despite universal nuances of chromatic color metaphors, some specific ones emerge due to various external factors, such as environment, education, history, politic, law, religion, literature, and other socio cultural facts that are specifically found and practiced in Indonesia.

A colorimetric method for highly sensitive and accurate detection of iodide by finding the critical color in a color change process using silver triangular nanoplates

Energy Technology Data Exchange (ETDEWEB)

Yang, Xiu-Hua; Ling, Jian, E-mail: lingjian@ynu.edu.cn; Peng, Jun; Cao, Qiu-E., E-mail: qecao@ynu.edu.cn; Ding, Zhong-Tao; Bian, Long-Chun

2013-10-10

Graphical abstract: -- Highlights: •Demonstrated a new colorimetric strategy for iodide detection by silver nanoplates. •The colorimetric strategy is to find the critical color in a color change process. •The colorimetric strategy is more accurate and sensitive than common colorimetry. •Discovered a new morphological transformation phenomenon of silver nanoplates. -- Abstract: In this contribution, we demonstrated a novel colorimetric method for highly sensitive and accurate detection of iodide using citrate-stabilized silver triangular nanoplates (silver TNPs). Very lower concentration of iodide can induce an appreciable color change of silver TNPs solution from blue to yellow by fusing of silver TNPs to nanoparticles, as confirmed by UV–vis absorption spectroscopy and transmission electron microscopy (TEM). The principle of this colorimetric assay is not an ordinary colorimetry, but a new colorimetric strategy by finding the critical color in a color change process. With this strategy, 0.1 μM of iodide can be recognized within 30 min by naked-eyes observation, and lower concentration of iodide down to 8.8 nM can be detected using a spectrophotometer. Furthermore, this high sensitive colorimetric assay has good accuracy, stability and reproducibility comparing with other ordinary colorimetry. We believe this new colorimetric method will open up a fresh insight of simple, rapid and reliable detection of iodide and can find its future application in the biochemical analysis or clinical diagnosis.

A colorimetric method for highly sensitive and accurate detection of iodide by finding the critical color in a color change process using silver triangular nanoplates

International Nuclear Information System (INIS)

Yang, Xiu-Hua; Ling, Jian; Peng, Jun; Cao, Qiu-E.; Ding, Zhong-Tao; Bian, Long-Chun

2013-01-01

Graphical abstract: -- Highlights: •Demonstrated a new colorimetric strategy for iodide detection by silver nanoplates. •The colorimetric strategy is to find the critical color in a color change process. •The colorimetric strategy is more accurate and sensitive than common colorimetry. •Discovered a new morphological transformation phenomenon of silver nanoplates. -- Abstract: In this contribution, we demonstrated a novel colorimetric method for highly sensitive and accurate detection of iodide using citrate-stabilized silver triangular nanoplates (silver TNPs). Very lower concentration of iodide can induce an appreciable color change of silver TNPs solution from blue to yellow by fusing of silver TNPs to nanoparticles, as confirmed by UV–vis absorption spectroscopy and transmission electron microscopy (TEM). The principle of this colorimetric assay is not an ordinary colorimetry, but a new colorimetric strategy by finding the critical color in a color change process. With this strategy, 0.1 μM of iodide can be recognized within 30 min by naked-eyes observation, and lower concentration of iodide down to 8.8 nM can be detected using a spectrophotometer. Furthermore, this high sensitive colorimetric assay has good accuracy, stability and reproducibility comparing with other ordinary colorimetry. We believe this new colorimetric method will open up a fresh insight of simple, rapid and reliable detection of iodide and can find its future application in the biochemical analysis or clinical diagnosis

Using color management in color document processing

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Nehab, Smadar

1995-04-01

Color Management Systems have been used for several years in Desktop Publishing (DTP) environments. While this development hasn't matured yet, we are already experiencing the next generation of the color imaging revolution-Device Independent Color for the small office/home office (SOHO) environment. Though there are still open technical issues with device independent color matching, they are not the focal point of this paper. This paper discusses two new and crucial aspects in using color management in color document processing: the management of color objects and their associated color rendering methods; a proposal for a precedence order and handshaking protocol among the various software components involved in color document processing. As color peripherals become affordable to the SOHO market, color management also becomes a prerequisite for common document authoring applications such as word processors. The first color management solutions were oriented towards DTP environments whose requirements were largely different. For example, DTP documents are image-centric, as opposed to SOHO documents that are text and charts centric. To achieve optimal reproduction on low-cost SOHO peripherals, it is critical that different color rendering methods are used for the different document object types. The first challenge in using color management of color document processing is the association of rendering methods with object types. As a result of an evolutionary process, color matching solutions are now available as application software, as driver embedded software and as operating system extensions. Consequently, document processing faces a new challenge, the correct selection of the color matching solution while avoiding duplicate color corrections.

Dry Eye

Science.gov (United States)

... Eye » Facts About Dry Eye Listen Facts About Dry Eye Fact Sheet Blurb The National Eye Institute (NEI) ... and their families search for general information about dry eye. An eye care professional who has examined the ...

Automatic color preference correction for color reproduction

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Tsukada, Masato; Funayama, Chisato; Tajima, Johji

2000-12-01

The reproduction of natural objects in color images has attracted a great deal of attention. Reproduction more pleasing colors of natural objects is one of the methods available to improve image quality. We developed an automatic color correction method to maintain preferred color reproduction for three significant categories: facial skin color, green grass and blue sky. In this method, a representative color in an object area to be corrected is automatically extracted from an input image, and a set of color correction parameters is selected depending on the representative color. The improvement in image quality for reproductions of natural image was more than 93 percent in subjective experiments. These results show the usefulness of our automatic color correction method for the reproduction of preferred colors.

Choosing the Right Color: A Way to Increase Sales

OpenAIRE

Dr.Zahra Hossein Nezhad; Katayoun Kavehnezhad

2013-01-01

It can be stated that the colors are one of the most important and powerful tools of design for marketing materials such as web sites, direct mail, ads, and etc. Meanings and Usage of Color can vary from country to country. Therefore, it is necessary to identify each culture color psychology for correct use of color. This paper focuses on the psychological meaning of each color and suggests using it in the correct position. To this purpose the relationship between color and culture, gender, e...

The Impact of Color-Coding Freshmen Integrated-Science Assignments on Student Achievement

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Sturdivant Allen, Anita Kay

Students in Grade 9 exhibit high rates of grade retention and absenteeism. Educators have used different strategies that will increase the achievement of those students. The purpose of this study was to determine whether a relationship existed between student achievement and the strategy to use colored paper for Grade 9 science assignments and tests. Itten's color theory provided the theoretical framework. Itten was one of the first researchers to explore the notion that the human eye can detect wavelengths as colors and that those colors can engage and create order in the human brain. A sample of students assigned to 4 classroom teachers at one high school who volunteered to take part in the study for 18 weeks were used in this quantitative study. Teachers administered student assessments on blue, green, yellow, and white paper. Each class was assigned 1 of the 4 colors for 4.5 weeks. The classes were then assigned a different color for the same length of time until each class had exposure to all 4 colors. Physical science exams given to students in the same grade or subject were used as the dependent variable. An ANOVA indicated that the groups using blue paper scored the highest on the physical science exams; students who used white paper earned the lowest scores. When comparing all 3 groups using colored paper (all three colored paper groups combined into one group) to the white paper groups, t-test results indicated that students using any colored paper scored higher than students using white paper. Further research on the impact of colored paper on student academic performance is necessary. Implications for positive social change indicate that new knowledge about instructional tools that impact student achievement deserves more attention.

Embedding Color Watermarks in Color Images

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Wu Tung-Lin

2003-01-01

Full Text Available Robust watermarking with oblivious detection is essential to practical copyright protection of digital images. Effective exploitation of the characteristics of human visual perception to color stimuli helps to develop the watermarking scheme that fills the requirement. In this paper, an oblivious watermarking scheme that embeds color watermarks in color images is proposed. Through color gamut analysis and quantizer design, color watermarks are embedded by modifying quantization indices of color pixels without resulting in perceivable distortion. Only a small amount of information including the specification of color gamut, quantizer stepsize, and color tables is required to extract the watermark. Experimental results show that the proposed watermarking scheme is computationally simple and quite robust in face of various attacks such as cropping, low-pass filtering, white-noise addition, scaling, and JPEG compression with high compression ratios.

Using eye tracking technology to compare the effectiveness of malignant hyperthermia cognitive aid design.

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King, Roderick; Hanhan, Jaber; Harrison, T Kyle; Kou, Alex; Howard, Steven K; Borg, Lindsay K; Shum, Cynthia; Udani, Ankeet D; Mariano, Edward R

2018-05-15

Malignant hyperthermia is a rare but potentially fatal complication of anesthesia, and several different cognitive aids designed to facilitate a timely and accurate response to this crisis currently exist. Eye tracking technology can measure voluntary and involuntary eye movements, gaze fixation within an area of interest, and speed of visual response and has been used to a limited extent in anesthesiology. With eye tracking technology, we compared the accessibility of five malignant hyperthermia cognitive aids by collecting gaze data from twelve volunteer participants. Recordings were reviewed and annotated to measure the time required for participants to locate objects on the cognitive aid to provide an answer; cumulative time to answer was the primary outcome. For the primary outcome, there were differences detected between cumulative time to answer survival curves (P typescript with minimal use of single color blocking.

Hot colors: the nature and specificity of color-induced nasal thermal sensations.

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Michael, George A; Galich, Hélène; Relland, Solveig; Prud'hon, Sabine

2010-03-05

The nature of the recently discovered color-induced nasal thermal sensations was investigated in four Experiments. Subjects were required to fixate a bottle containing a red or green solution presented centrally (Exp1 and Exp4) or laterally (Exp2) and to sniff another bottle, always the same one, but which they were not allowed to see, containing 10 ml of a colorless, odorless and trigeminal-free solution. Each nostril was tested separately, and subjects were asked whether the sniffed solution induced warming or cooling sensations (plus an ambient sensation in Exp4) in the nasal cavity. The results of Experiments 1 and 2 confirmed the warming/left nostril-cooling/right nostril dissociation, suggesting the existence of different lateralized processes for thermal processing. However, Experiment 2 failed to demonstrate dominance of warming responses when subjects' eyes were directed to the left or cooling responses when they were directed to the right. Nor did gaze direction interact with the tested nostril. This suggests that the color-induced thermal sensations are specifically related to the nasal trigeminal system, rather than a general process related to general hemispheric activity. When the exposed bottles were colorless (Exp3), no lateralized patterns were observed, suggesting, in combination with the results of Experiments 1 and 2, that both color cues and nasal stimulations are necessary for lateralized patterns to arise. Rendering the temperature judgment even more difficult (Exp4), made the lateralized patterns shift towards the associated (i.e., ambient) responses. The results are discussed in a general framework which considers that, even in the absence of real thermal stimulus, preparing to process thermal stimuli in the nasal cavity may activate the underlying lateralized neural mechanisms, and that those mechanisms are reflected in the responses. Copyright 2009 Elsevier B.V. All rights reserved.

1-Colored Archetypal Permutations and Strings of Degree n

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Gheorghe Eduard Tara

2012-10-01

Full Text Available New notions related to permutations are introduced here. We present the string of a 1-colored permutation as a closed planar curve, the fundamental 1-colored permutation as an equivalence class related to the equivalence in strings of the 1-colored permutations. We give formulas for the number of the 1-colored archetypal permutations of degree n. We establish an algorithm to identify the 1- colored archetypal permutations of degree n and we present the atlas of the 1-colored archetypal strings of degree n, n ≤ 7, based on this algorithm.

Color features for quality control in ceramic tile industry

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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.

Naked-eye sensor for rapid determination of mercury ion.

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Liu, Jing; Wu, Dapeng; Yan, Xiaohui; Guan, Yafeng

2013-11-15

A naked-eye paper sensor for rapid determination of trace mercury ion in water samples was designed and demonstrated. The mercury-sensing rhodamine B thiolactone was immobilized in silica matrices and the silica matrices were impregnated firmly and uniformly in the filter paper. As water samples flow through the filter paper, the membrane color will change from white to purple red, which could be observed obviously with naked eye, when concentration of mercury ions equals to or exceeds 10nM, the maximum residue level in drinking water recommended by U.S. EPA. The color change can also be recorded by a flatbed scanner and then digitized, reducing the detection limit of Hg(2+) down to 1.2 nM. Moreover, this method is extremely specific for Hg(2+) and shows a high tolerance ratio of interferent coexisting ions. The presence of Na(+) (2 mM), K(+) (2 mM), Fe(3+) (0.1 mM), Zn(2+) (0.1 mM), Mg(2+) (0.1 mM), Ni(2+) (50 μM), Co(2+) (50 μM), Cd(2+) (50 μM), Pb(2+) (50 μM), Cu(2+) (50 μM) and Ag(+) (3.5 μM) did not interfere with the detection of Hg(2+) (25 nM). Finally, the present method was applied in the detection of Hg(2+) in mineral water, tap water and pond water. Copyright © 2013 Elsevier B.V. All rights reserved.

Automatic removal of eye-movement and blink artifacts from EEG signals.

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Gao, Jun Feng; Yang, Yong; Lin, Pan; Wang, Pei; Zheng, Chong Xun

2010-03-01

Frequent occurrence of electrooculography (EOG) artifacts leads to serious problems in interpreting and analyzing the electroencephalogram (EEG). In this paper, a robust method is presented to automatically eliminate eye-movement and eye-blink artifacts from EEG signals. Independent Component Analysis (ICA) is used to decompose EEG signals into independent components. Moreover, the features of topographies and power spectral densities of those components are extracted to identify eye-movement artifact components, and a support vector machine (SVM) classifier is adopted because it has higher performance than several other classifiers. The classification results show that feature-extraction methods are unsuitable for identifying eye-blink artifact components, and then a novel peak detection algorithm of independent component (PDAIC) is proposed to identify eye-blink artifact components. Finally, the artifact removal method proposed here is evaluated by the comparisons of EEG data before and after artifact removal. The results indicate that the method proposed could remove EOG artifacts effectively from EEG signals with little distortion of the underlying brain signals.

Color evaluation of computer-generated color rainbow holography

International Nuclear Information System (INIS)

Shi, Yile; Wang, Hui; Wu, Qiong

2013-01-01

A color evaluation approach for computer-generated color rainbow holography (CGCRH) is presented. Firstly, the relationship between color quantities of a computer display and a color computer-generated holography (CCGH) colorimetric system is discussed based on color matching theory. An isochromatic transfer relationship of color quantity and amplitude of object light field is proposed. Secondly, the color reproduction mechanism and factors leading to the color difference between the color object and the holographic image that is reconstructed by CGCRH are analyzed in detail. A quantitative color calculation method for the holographic image reconstructed by CGCRH is given. Finally, general color samples are selected as numerical calculation test targets and the color differences between holographic images and test targets are calculated based on our proposed method. (paper)

Color planner for designers based on color emotions

Science.gov (United States)

Cheng, Ka-Man; Xin, John H.; Taylor, Gail

2002-06-01

During the color perception process, an associated feeling or emotion is induced in our brains, and this kind of emotion is termed as 'color emotion.' The researchers in the field of color emotions have put many efforts in quantifying color emotions with the standard color specifications and evaluating the influence of hue, lightness and chroma to the color emotions of human beings. In this study, a color planner was derived according to these findings so that the correlation of color emotions and standard color specifications was clearly indicated. Since people of different nationalities usually have different color emotions as different cultural and traditional backgrounds, the subjects in this study were all native Hong Kong Chinese and the color emotion words were all written in Chinese language in the visual assessments. Through the color planner, the designers from different areas, no matter fashion, graphic, interior or web site etc., can select suitable colors for inducing target color emotions to the customers or product-users since different colors convey different meanings to them. In addition, the designers can enhance the functionality and increase the attractiveness of their designed products by selecting suitable colors.

The nature of instructional effects in color constancy.

Science.gov (United States)

Radonjić, Ana; Brainard, David H

2016-06-01

The instructions subjects receive can have a large effect on experimentally measured color constancy, but the nature of these effects and how their existence should inform our understanding of color perception remains unclear. We used a factorial design to measure how instructional effects on constancy vary with experimental task and stimulus set. In each of 2 experiments, we employed both a classic adjustment-based asymmetric matching task and a novel color selection task. Four groups of naive subjects were instructed to make adjustments/selections based on (a) color (neutral instructions); (b) the light reaching the eye (physical spectrum instructions); (c) the actual surface reflectance of an object (objective reflectance instructions); or (d) the apparent surface reflectance of an object (apparent reflectance instructions). Across the 2 experiments we varied the naturalness of the stimuli. We find clear interactions between instructions, task, and stimuli. With simplified stimuli (Experiment 1), instructional effects were large and the data revealed 2 instruction-dependent patterns. In 1 (neutral and physical spectrum instructions) constancy was low, intersubject variability was also low, and adjustment-based and selection-based constancy were in agreement. In the other (reflectance instructions) constancy was high, intersubject variability was large, adjustment-based constancy deviated from selection-based constancy and for some subjects selection-based constancy increased across sessions. Similar patterns held for naturalistic stimuli (Experiment 2), although instructional effects were smaller. We interpret these 2 patterns as signatures of distinct task strategies-1 is perceptual, with judgments based primarily on the perceptual representation of color; the other involves explicit instruction-driven reasoning. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Eye development in the four-eyed fish Anableps anableps: cranial and retinal adaptations to simultaneous aerial and aquatic vision.

Science.gov (United States)

Perez, Louise N; Lorena, Jamily; Costa, Carinne M; Araujo, Maysa S; Frota-Lima, Gabriela N; Matos-Rodrigues, Gabriel E; Martins, Rodrigo A P; Mattox, George M T; Schneider, Patricia N

2017-04-12

The unique eyes of the four-eyed fish Anableps anableps have long intrigued biologists. Key features associated with the bulging eye of Anableps include the expanded frontal bone and the duplicated pupils and cornea. Furthermore, the Anableps retina expresses different photoreceptor genes in dorsal and ventral regions, potentially associated with distinct aerial and aquatic stimuli. To gain insight into the developmental basis of the Anableps unique eye, we examined neurocranium and eye ontogeny, as well as photoreceptor gene expression during larval stages. First, we described six larval stages during which duplication of eye structures occurs. Our osteological analysis of neurocranium ontogeny revealed another distinctive Anablepid feature: an ossified interorbital septum partially separating the orbital cavities. Furthermore, we identified the onset of differences in cell proliferation and cell layer density between dorsal and ventral regions of the retina. Finally, we show that differential photoreceptor gene expression in the retina initiates during development, suggesting that it is inherited and not environmentally determined. In sum, our results shed light on the ontogenetic steps leading to the highly derived Anableps eye. © 2017 The Author(s).

Spatial Distribution of Flower Color Induced by Interspecific Sexual Interaction.

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Yuma Takahashi

Full Text Available Understanding the mechanisms shaping the spatiotemporal distribution of species has long been a central concern of ecology and evolutionary biology. Contemporary patterns of plant assemblies suggest that sexual interactions among species, i.e., reproductive interference, lead to the exclusive distributions of closely related species that share pollinators. However, the fitness consequences and the initial ecological/evolutionary responses to reproductive interference remain unclear in nature, since reproductive isolation or allopatric distribution has already been achieved in the natural community. In Japan, three species of blue-eyed grasses (Sisyrinchium with incomplete reproductive isolation have recently colonized and occur sympatrically. Two of them are monomorphic with white flowers, whereas the other exhibits heritable color polymorphism (white and purple morphs. Here we investigated the effects of the presence of two monomorphic species on the distribution and reproductive success of color morphs. The frequency and reproductive success of white morphs decreased in area where monomorphic species were abundant, while those of purple morphs did not. The rate of hybridization between species was higher in white morphs than in the purple ones. Resource competition and habitat preference seemed not to contribute to the spatial distribution and reproductive success of two morphs. Our results supported that color-dependent reproductive interference determines the distribution of flower color polymorphism in a habitat, implying ecological sorting promoted by pollinator-mediated reproductive interference. Our study helps us to understand the evolution and spatial structure of flower color in a community.

Treatment of Dry Eye Disease.

Science.gov (United States)

Marshall, Leisa L; Roach, J Michael

2016-02-01

Review of the etiology, clinical manifestations, and treatment of dry eye disease (DED). Articles indexed in PubMed (National Library of Medicine), Iowa Drug Information Service (IDIS), and the Cochrane Reviews and Trials in the last 10 years using the key words "dry eye disease," "dry eye syndrome," "dry eye and treatment." Primary sources were used to locate additional resources. Sixty-eight publications were reviewed, and criteria supporting the primary objective were used to identify useful resources. The literature included practice guidelines, book chapters, review articles, original research articles, and product prescribing information for the etiology, clinical manifestations, diagnosis, and treatment of DED. DED is one of the most common ophthalmic disorders. Signs and symptoms of DED vary by patient, but may include ocular irritation, redness, itching, photosensitivity, visual blurring, mucous discharge, and decreased tear meniscus or break-up time. Symptoms improve with treatment, but the condition is not completely curable. Treatment includes reducing environmental causes, discontinuing medications that cause or worsen dry eye, and managing contributing ocular or systemic conditions. Most patients use nonprescription tear substitutes, and if these are not sufficient, other treatment is prescribed. These treatments include the ophthalmic anti-inflammatory agent cyclosporine, punctal occlusion, eye side shields, systemic cholinergic agents, and autologous serum tears. This article reviews the etiology, symptoms, and current therapy for DED.

Color blindness and contrast perception in cuttlefish (Sepia officinalis) determined by a visual sensorimotor assay.

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Mäthger, Lydia M; Barbosa, Alexandra; Miner, Simon; Hanlon, Roger T

2006-05-01

We tested color perception based upon a robust behavioral response in which cuttlefish (Sepia officinalis) respond to visual stimuli (a black and white checkerboard) with a quantifiable, neurally controlled motor response (a body pattern). In the first experiment, we created 16 checkerboard substrates in which 16 grey shades (from white to black) were paired with one green shade (matched to the maximum absorption wavelength of S. officinalis' sole visual pigment, 492 nm), assuming that one of the grey shades would give a similar achromatic signal to the tested green. In the second experiment, we created a checkerboard using one blue and one yellow shade whose intensities were matched to the cuttlefish's visual system. In both assays it was tested whether cuttlefish would show disruptive coloration on these checkerboards, indicating their ability to distinguish checkers based solely on wavelength (i.e., color). Here, we show clearly that cuttlefish must be color blind, as they showed non-disruptive coloration on the checkerboards whose color intensities were matched to the Sepia visual system, suggesting that the substrates appeared to their eyes as uniform backgrounds. Furthermore, we show that cuttlefish are able to perceive objects in their background that differ in contrast by approximately 15%. This study adds support to previous reports that S. officinalis is color blind, yet the question of how cuttlefish achieve "color-blind camouflage" in chromatically rich environments still remains.

Colorization-Based RGB-White Color Interpolation using Color Filter Array with Randomly Sampled Pattern.

Science.gov (United States)

Oh, Paul; Lee, Sukho; Kang, Moon Gi

2017-06-28

Recently, several RGB-White (RGBW) color filter arrays (CFAs) have been proposed, which have extra white (W) pixels in the filter array that are highly sensitive. Due to the high sensitivity, the W pixels have better SNR (Signal to Noise Ratio) characteristics than other color pixels in the filter array, especially, in low light conditions. However, most of the RGBW CFAs are designed so that the acquired RGBW pattern image can be converted into the conventional Bayer pattern image, which is then again converted into the final color image by using conventional demosaicing methods, i.e., color interpolation techniques. In this paper, we propose a new RGBW color filter array based on a totally different color interpolation technique, the colorization algorithm. The colorization algorithm was initially proposed for colorizing a gray image into a color image using a small number of color seeds. Here, we adopt this algorithm as a color interpolation technique, so that the RGBW color filter array can be designed with a very large number of W pixels to make the most of the highly sensitive characteristics of the W channel. The resulting RGBW color filter array has a pattern with a large proportion of W pixels, while the small-numbered RGB pixels are randomly distributed over the array. The colorization algorithm makes it possible to reconstruct the colors from such a small number of RGB values. Due to the large proportion of W pixels, the reconstructed color image has a high SNR value, especially higher than those of conventional CFAs in low light condition. Experimental results show that many important information which are not perceived in color images reconstructed with conventional CFAs are perceived in the images reconstructed with the proposed method.

Of colored numbers and numbered colors: interactive processes in grapheme-color synesthesia.

Science.gov (United States)

Gebuis, Titia; Nijboer, Tanja C W; van der Smagt, Maarten J

2009-01-01

Grapheme-color synesthetes experience a specific color when they see a grapheme but they do not report to perceive a grapheme when a color is presented. In this study, we investigate whether color can still evoke number-processes even when a vivid number experience is absent. We used color-number and number-color priming, both revealing faster responses in congruent compared to incongruent conditions. Interestingly, the congruency effect was of similar magnitude for both conditions, and a numerical distance effect was present only in the color-number priming task. In addition, a priming task in which synesthetes had to judge the parity of a colored number revealed faster responses in parity congruent than in parity incongruent trials. These combined results demonstrate that synesthesia is indeed bi-directional and of similar strength in both directions. Furthermore, they illustrate the precise nature of these interactions and show that the direction of these interactions is determined by task demands, not by the more vividly experienced aspect of the stimulus.

Black Feminism: What Women of Color Went Through in Toni Morrison’s Selected Novels

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Ayda Rahmani

2015-05-01

Full Text Available This article examines two of Toni Morrison’s novels, The Bluest Eye and Beloved in the lights of black feminism, racism, realism and naturalism. It is an attempt to reflect the powerlessness, inhumanity, and pains that women of color went through.  By using a feminist racist and naturalist filter,  a descriptive-analytical method of study and by analyzing the situations, the characters and themes, the status of women of color  in Literature based on Morrison’s selected  novels are revealed and represented. Morrison very well describes how different women characters react and respond differently to the injustice and the inhumanity imposed on them through for example the contrasting nature of Sethe in Beloved and Pauline in The Bluest Eye. She depicts the bravery and courage in Sethe , the self-absorbedness in Pauline and the passiveness in Pecola all of which raise powerful questions regarding black-women’s self-identity, self-concept, and  struggles to achieve freedom as a living being if not a human being: a path which will deepen our understanding of  women issues in general. The researcher believes that a womanish and racist study of the selected novels would contribute to broaden our views of humanity. The researcher selected women of color because she thinks the sorrows of black women, and the pains and toils they went through have always been deeper than those of the white ones.

Nature's palette: the search for natural blue colorants.

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Newsome, Andrew G; Culver, Catherine A; van Breemen, Richard B

2014-07-16

The food and beverage industry is seeking to broaden the palette of naturally derived colorants. Although considerable effort has been devoted to the search for new blue colorants in fruits and vegetables, less attention has been directed toward blue compounds from other sources such as bacteria and fungi. The current work reviews known organic blue compounds from natural plant, animal, fungal, and microbial sources. The scarcity of blue-colored metabolites in the natural world relative to metabolites of other colors is discussed, and structural trends common among natural blue compounds are identified. These compounds are grouped into seven structural classes and evaluated for their potential as new color additives.

Comparison of the influence of stimuli color on Steady-State Visual Evoked Potentials

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Richard Junior Manuel Godinez Tello

Full Text Available IntroductionThe main idea of a traditional Steady State Visually Evoked Potentials (SSVEP-BCI is the activation of commands through gaze control. For this purpose, the retina of the eye is excited by a stimulus at a certain frequency. Several studies have shown effects related to different kind of stimuli, frequencies, window lengths, techniques of feature extraction and even classification. So far, none of the previous studies has performed a comparison of performance of stimuli colors through LED technology. This study addresses precisely this important aspect and would be a great contribution to the topic of SSVEP-BCIs. Additionally, the performance of different colors at different frequencies and the visual comfort were evaluated in each case.MethodsLEDs of four different colors (red, green, blue and yellow flickering at four distinct frequencies (8, 11, 13 and 15 Hz were used. Twenty subjects were distributed in two groups performing different protocols. Multivariate Synchronization Index (MSI was the technique adopted as feature extractor.ResultsThe accuracy was gradually enhanced with the increase of the time window. From our observations, the red color provides, in most frequencies, both highest rates of accuracy and Information Transfer Rate (ITR for detection of SSVEP.ConclusionAlthough the red color has presented higher ITR, this color was turned in the less comfortable one and can even elicit epileptic responses according to the literature. For this reason, the green color is suggested as the best choice according to the proposed rules. In addition, this color has shown to be safe and accurate for an SSVEP-BCI.

Models for Primary Eye Care Services in India

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Vasundhra Misra

2015-01-01

In the current situation, an integrated health care system with primary eye care promoted by government of India is apparently the best answer. This model is both cost effective and practical for the prevention and control of blindness among the underprivileged population. Other models functioning with the newer technology of tele-ophthalmology or mobile clinics also add to the positive outcome in providing primary eye care services. This review highlights the strengths and weaknesses of various models presently functioning in the country with the idea of providing useful inputs for eye care providers and enabling them to identify and adopt an appropriate model for primary eye care services.

Precision of synesthetic color matching resembles that for recollected colors rather than physical colors.

Science.gov (United States)

Arnold, Derek H; Wegener, Signy V; Brown, Francesca; Mattingley, Jason B

2012-10-01

Grapheme-color synesthesia is an atypical condition in which individuals experience sensations of color when reading printed graphemes such as letters and digits. For some grapheme-color synesthetes, seeing a printed grapheme triggers a sensation of color, but hearing the name of a grapheme does not. This dissociation allowed us to compare the precision with which synesthetes are able to match their color experiences triggered by visible graphemes, with the precision of their matches for recalled colors based on the same graphemes spoken aloud. In six synesthetes, color matching for printed graphemes was equally variable relative to recalled experiences. In a control experiment, synesthetes and age-matched controls either matched the color of a circular patch while it was visible on a screen, or they judged its color from memory after it had disappeared. Both synesthetes and controls were more variable when matching from memory, and the variance of synesthetes' recalled color judgments matched that associated with their synesthetic judgments for visible graphemes in the first experiment. Results suggest that synesthetic experiences of color triggered by achromatic graphemes are analogous to recollections of color.

A laboratory evaluation of color video monitors

Energy Technology Data Exchange (ETDEWEB)

Terry, P.L.

1993-07-01

Sandia National Laboratories has considerable experience with monochrome video monitors used in alarm assessment video systems. Most of these systems, used for perimeter protection, were designed to classify rather than to identify intruders. There is a growing interest in the identification function of security video systems for both access control and insider protection. Because color video technology is rapidly changing and because color information is useful for identification purposes, Sandia National Laboratories established a program to evaluate the newest relevant color video equipment. This report documents the evaluation of an integral component, color monitors. It briefly discusses a critical parameter, dynamic range, details test procedures, and evaluates the results.

A laboratory evaluation of color video monitors

International Nuclear Information System (INIS)

Terry, P.L.

1993-07-01

Sandia National Laboratories has considerable experience with monochrome video monitors used in alarm assessment video systems. Most of these systems, used for perimeter protection, were designed to classify rather than to identify intruders. There is a growing interest in the identification function of security video systems for both access control and insider protection. Because color video technology is rapidly changing and because color information is useful for identification purposes, Sandia National Laboratories established a program to evaluate the newest relevant color video equipment. This report documents the evaluation of an integral component, color monitors. It briefly discusses a critical parameter, dynamic range, details test procedures, and evaluates the results

Color Terms and Color Concepts

Science.gov (United States)

Davidoff, Jules

2006-01-01

In their lead articles, both Kowalski and Zimiles (2006) and O'Hanlon and Roberson (2006) declare a general relation between color term knowledge and the ability to conceptually represent color. Kowalski and Zimiles, in particular, argue for a priority for the conceptual representation in color term acquisition. The complexities of the interaction…

Color Categories and Color Appearance

Science.gov (United States)

Webster, Michael A.; Kay, Paul

2012-01-01

We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue-green boundary, to test whether chromatic differences across the boundary…

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.

Color Memory of University Students: Influence of Color Experience and Color Characteristic

Science.gov (United States)

Bynum, Carlisle; Epps, Helen H.; Kaya, Naz

2006-01-01

The ability to select a previously viewed color specimen from an array of specimens that differ in hue, value, or chroma varies among individuals, and may be related to one's basic color discrimination ability or to prior experience with color. This study investigated short-term color memory of 40 college students, 20 of whom were interior design…

Australoheros mattosi Ottoni, 2012 (Teleostei: Cichlidae: live coloration, population differences, and new data on adult external anatomy

Directory of Open Access Journals (Sweden)

Gilmar Ferreira Carmo

2016-02-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2016v29n1p55 Recently collected specimens of Australoheros mattosi in water courses around locality type (Das Velhas River drainage, including Upper Cipó River, Minas Gerais, Brazil revealed new data on the adult live coloration (iridescent markings on the base of the dorsal and anal fins and reddish to grayish hyaline coloration on the distal margin of the caudal-fin, population (dorsal head profile and head ground coloration and ontogenetic variations (variation in the nostril position, head ventral profile, scales on the cheek and the anal and dorsal fins, spot on the posterior margin of the operculum, and ground coloration in alcohol on the external morphology and new morphometric data (pelvic-pectoral distance, eye position in relation to the horizontal axis at the symphysis and the 5th ceratobranchial levels on adult individuals.

Conceptualizing Color-Evasiveness: Using Dis/Ability Critical Race Theory to Expand a Color-Blind Racial Ideology in Education and Society

Science.gov (United States)

Annamma, Subini Ancy; Jackson, Darrell D.; Morrison, Deb

2017-01-01

Color-blind racial ideology has historically been conceptualized as an ideology wherein race is immaterial. Efforts not to "see" race insinuate that recognizing race is problematic; therefore, scholars have identified and critiqued color-blindness ideology. In this paper, we first examine Gotanda's (1991) identification and critique of…

Memory for color reactivates color processing region.

Science.gov (United States)

Slotnick, Scott D

2009-11-25

Memory is thought to be constructive in nature, where features processed in different cortical regions are synthesized during retrieval. In an effort to support this constructive memory framework, the present functional magnetic resonance imaging study assessed whether memory for color reactivated color processing regions. During encoding, participants were presented with colored and gray abstract shapes. During retrieval, old and new shapes were presented in gray and participants responded 'old-colored', 'old-gray', or 'new'. Within color perception regions, color memory related activity was observed in the left fusiform gyrus, adjacent to the collateral sulcus. A retinotopic mapping analysis indicated this activity occurred within color processing region V8. The present feature specific evidence provides compelling support for a constructive view of memory.

Genetic Recombination Between Stromal and Cancer Cells Results in Highly Malignant Cells Identified by Color-Coded Imaging in a Mouse Lymphoma Model.

Science.gov (United States)

Nakamura, Miki; Suetsugu, Atsushi; Hasegawa, Kousuke; Matsumoto, Takuro; Aoki, Hitomi; Kunisada, Takahiro; Shimizu, Masahito; Saji, Shigetoyo; Moriwaki, Hisataka; Hoffman, Robert M

2017-12-01

The tumor microenvironment (TME) promotes tumor growth and metastasis. We previously established the color-coded EL4 lymphoma TME model with red fluorescent protein (RFP) expressing EL4 implanted in transgenic C57BL/6 green fluorescent protein (GFP) mice. Color-coded imaging of the lymphoma TME suggested an important role of stromal cells in lymphoma progression and metastasis. In the present study, we used color-coded imaging of RFP-lymphoma cells and GFP stromal cells to identify yellow-fluorescent genetically recombinant cells appearing only during metastasis. The EL4-RFP lymphoma cells were injected subcutaneously in C57BL/6-GFP transgenic mice and formed subcutaneous tumors 14 days after cell transplantation. The subcutaneous tumors were harvested and transplanted to the abdominal cavity of nude mice. Metastases to the liver, perigastric lymph node, ascites, bone marrow, and primary tumor were imaged. In addition to EL4-RFP cells and GFP-host cells, genetically recombinant yellow-fluorescent cells, were observed only in the ascites and bone marrow. These results indicate genetic exchange between the stromal and cancer cells. Possible mechanisms of genetic exchange are discussed as well as its ramifications for metastasis. J. Cell. Biochem. 118: 4216-4221, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

IRAS Colors of the Pleiades

Science.gov (United States)

Carey, Sean J.; Shipman, R. F.; Clark, F. O.

1996-01-01

We present large scale images of the infrared emission of the region around the Pleiades using the ISSA data product from the IRAS mission. Residual Zodiacal background and a discontinuity in the image due to the scanning strategy of the satellite necessitated special background subtraction methods. The 60/100 color image clearly shows the heating of the ambient interstellar medium by the cluster. The 12/100 and 25/100 images peak on the cluster as expected for exposure of small dust grains to an enhanced UV radiation field; however, the 25/100 color declines to below the average interstellar value at the periphery of the cluster. Potential causes of the color deficit are discussed. A new method of identifying dense molecular material through infrared emission properties is presented. The difference between the 100 micron flux density and the 60 micron flux density scaled by the average interstellar 60/100 color ratio (Delta I(sub 100) is a sensitive diagnostic of material with embedded heating sources (Delta I(sub 100) less than 0) and cold, dense cores (Delta I(sub 100) greater than 0). The dense cores of the Taurus cloud complex as well as Lynds 1457 are clearly identified by this method, while the IR bright but diffuse Pleiades molecular cloud is virtually indistinguishable from the nearby infrared cirrus.

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.

Dry eye syndrome among computer users

Science.gov (United States)

Gajta, Aurora; Turkoanje, Daniela; Malaescu, Iosif; Marin, Catalin-Nicolae; Koos, Marie-Jeanne; Jelicic, Biljana; Milutinovic, Vuk

2015-12-01

Dry eye syndrome is characterized by eye irritation due to changes of the tear film. Symptoms include itching, foreign body sensations, mucous discharge and transitory vision blurring. Less occurring symptoms include photophobia and eye tiredness. Aim of the work was to determine the quality of the tear film and ocular dryness potential risk in persons who spend more than 8 hours using computers and possible correlations between severity of symptoms (dry eyes symptoms anamnesis) and clinical signs assessed by: Schirmer test I, TBUT (Tears break-up time), TFT (Tear ferning test). The results show that subjects using computer have significantly shorter TBUT (less than 5 s for 56 % of subjects and less than 10 s for 37 % of subjects), TFT type II/III in 50 % of subjects and type III 31% of subjects was found when compared to computer non users (TFT type I and II was present in 85,71% of subjects). Visual display terminal use, more than 8 hours daily, has been identified as a significant risk factor for dry eye. It's been advised to all persons who spend substantial time using computers to use artificial tears drops in order to minimize the symptoms of dry eyes syndrome and prevents serious complications.

Eye Protection

OpenAIRE

Pashby, Tom

1986-01-01

Eye injuries frequently occur in the home, at work and at play. Many result in legally blind eyes, and most are preventable. Awareness of potential hazards is essential to preventing eye injuries, particularly in children. In addition, protective devices must be used appropriately. We have developed eye protectors that have proved effective in reducing both the overall incidence and the severity of sports eye injuries.

Diabetes eye exams

Science.gov (United States)

Diabetic retinopathy - eye exams; Diabetes - eye exams; Glaucoma - diabetic eye exam; Macular edema - diabetic eye exam ... if the doctor who takes care of your diabetes checks your eyes, you need an eye exam ...

Novel cellulose-based halochromic test strips for naked-eye detection of alkaline vapors and analytes.

Science.gov (United States)

Abou-Yousef, Hussein; Khattab, Tawfik A; Youssef, Yehia A; Al-Balakocy, Naser; Kamel, Samir

2017-08-01

A simple, portable and highly sensitive naked-eye test strip is successfully prepared for optical detection of gaseous and aqueous alkaline analytes. Novel pH-sensory tricyanofuran-hydrazone (TCFH) disperse colorant containing a hydrazone recognition functional moiety is successfully synthesized via azo-coupling reaction between active methyl-containing tricyanofuran (TCF) heterocycle and diazonium salt of 4-aminobenzaldehyde followed by Knoevenagel condensation with malononitrile. UV-vis absorption spectra display solvatochromism and reversible color changes of the TCFH solution in dimethyl sulfoxide in response to pH variations. We investigate the preparation of hydrophobic cellulose/polyethylene terephthalate composites characterized by their high affinity for disperse dyes. Composite films made from CA, Cell/CA, PET/CA, and Cell/PET-CA are produced via solvent-casting procedure using 10-30% modified cellulose or modified polyethylene terephthalate. The mechanical properties and morphologies of these composite films are investigated. The prepared pH-sensory hydrazone-based disperse dye is then applied to dye the produced cellulose-based composite films employing the high temperature pressure dyeing procedure. The produced halochromic PET-CA-TCFH test strip provide an instant visible signal from orange to purple upon exposure to alkaline conditions as proved by the coloration measurements. The sensor strip exhibits high sensitivity and quick detection toward ammonia in both of aqueous and vapor phases by naked-eye observations at room temperature and atmospheric pressure. Copyright © 2017 Elsevier B.V. All rights reserved.

Using Single Colors and Color Pairs to Communicate Basic Tastes II: Foreground-Background Color Combinations.

Science.gov (United States)

Woods, Andy T; Marmolejo-Ramos, Fernando; Velasco, Carlos; Spence, Charles

2016-01-01

People associate basic tastes (e.g., sweet, sour, bitter, and salty) with specific colors (e.g., pink or red, green or yellow, black or purple, and white or blue). In the present study, we investigated whether a color bordered by another color (either the same or different) would give rise to stronger taste associations relative to a single patch of color. We replicate previous findings, highlighting the existence of a robust crossmodal correspondence between individual colors and basic tastes. On occasion, color pairs were found to communicate taste expectations more consistently than were single color patches. Furthermore, and in contrast to a recent study in which the color pairs were shown side-by-side, participants took no longer to match the color pairs with tastes than the single colors (they had taken twice as long to respond to the color pairs in the previous study). Possible reasons for these results are discussed, and potential applications for the results, and for the testing methodology developed, are outlined.

Third eye, the biological effects; 3. oeil, les effets biologiques

Energy Technology Data Exchange (ETDEWEB)

Anon.

2004-02-01

The discovery of a third kind of photo-receptor cell in the human eye has permitted to better understand the biological effects of lighting, not only on the vision, but also on some nervous processes, like emotion, mood, stress, biological clock, etc.. This additional dimension has led the engineers of Philips Lighting company to launch a new indoor lighting concept named 'Carpe Diem'. This concept adapts both the illuminance and the color of a lighting system according to the type of work and to the expected stimulating effect. (J.S.)

Screening for Dyslexia Using Eye Tracking during Reading.

Science.gov (United States)

Nilsson Benfatto, Mattias; Öqvist Seimyr, Gustaf; Ygge, Jan; Pansell, Tony; Rydberg, Agneta; Jacobson, Christer

2016-01-01

Dyslexia is a neurodevelopmental reading disability estimated to affect 5-10% of the population. While there is yet no full understanding of the cause of dyslexia, or agreement on its precise definition, it is certain that many individuals suffer persistent problems in learning to read for no apparent reason. Although it is generally agreed that early intervention is the best form of support for children with dyslexia, there is still a lack of efficient and objective means to help identify those at risk during the early years of school. Here we show that it is possible to identify 9-10 year old individuals at risk of persistent reading difficulties by using eye tracking during reading to probe the processes that underlie reading ability. In contrast to current screening methods, which rely on oral or written tests, eye tracking does not depend on the subject to produce some overt verbal response and thus provides a natural means to objectively assess the reading process as it unfolds in real-time. Our study is based on a sample of 97 high-risk subjects with early identified word decoding difficulties and a control group of 88 low-risk subjects. These subjects were selected from a larger population of 2165 school children attending second grade. Using predictive modeling and statistical resampling techniques, we develop classification models from eye tracking records less than one minute in duration and show that the models are able to differentiate high-risk subjects from low-risk subjects with high accuracy. Although dyslexia is fundamentally a language-based learning disability, our results suggest that eye movements in reading can be highly predictive of individual reading ability and that eye tracking can be an efficient means to identify children at risk of long-term reading difficulties.

Screening for Dyslexia Using Eye Tracking during Reading.

Directory of Open Access Journals (Sweden)

Mattias Nilsson Benfatto

Full Text Available Dyslexia is a neurodevelopmental reading disability estimated to affect 5-10% of the population. While there is yet no full understanding of the cause of dyslexia, or agreement on its precise definition, it is certain that many individuals suffer persistent problems in learning to read for no apparent reason. Although it is generally agreed that early intervention is the best form of support for children with dyslexia, there is still a lack of efficient and objective means to help identify those at risk during the early years of school. Here we show that it is possible to identify 9-10 year old individuals at risk of persistent reading difficulties by using eye tracking during reading to probe the processes that underlie reading ability. In contrast to current screening methods, which rely on oral or written tests, eye tracking does not depend on the subject to produce some overt verbal response and thus provides a natural means to objectively assess the reading process as it unfolds in real-time. Our study is based on a sample of 97 high-risk subjects with early identified word decoding difficulties and a control group of 88 low-risk subjects. These subjects were selected from a larger population of 2165 school children attending second grade. Using predictive modeling and statistical resampling techniques, we develop classification models from eye tracking records less than one minute in duration and show that the models are able to differentiate high-risk subjects from low-risk subjects with high accuracy. Although dyslexia is fundamentally a language-based learning disability, our results suggest that eye movements in reading can be highly predictive of individual reading ability and that eye tracking can be an efficient means to identify children at risk of long-term reading difficulties.

The HydroColor App: Above Water Measurements of Remote Sensing Reflectance and Turbidity Using a Smartphone Camera.

Science.gov (United States)

Leeuw, Thomas; Boss, Emmanuel

2018-01-16

HydroColor is a mobile application that utilizes a smartphone's camera and auxiliary sensors to measure the remote sensing reflectance of natural water bodies. HydroColor uses the smartphone's digital camera as a three-band radiometer. Users are directed by the application to collect a series of three images. These images are used to calculate the remote sensing reflectance in the red, green, and blue broad wavelength bands. As with satellite measurements, the reflectance can be inverted to estimate the concentration of absorbing and scattering substances in the water, which are predominately composed of suspended sediment, chlorophyll, and dissolved organic matter. This publication describes the measurement method and investigates the precision of HydroColor's reflectance and turbidity estimates compared to commercial instruments. It is shown that HydroColor can measure the remote sensing reflectance to within 26% of a precision radiometer and turbidity within 24% of a portable turbidimeter. HydroColor distinguishes itself from other water quality camera methods in that its operation is based on radiometric measurements instead of image color. HydroColor is one of the few mobile applications to use a smartphone as a completely objective sensor, as opposed to subjective user observations or color matching using the human eye. This makes HydroColor a powerful tool for crowdsourcing of aquatic optical data.

A transmitting antenna with hexagon illumination shape for four-color VLC

Science.gov (United States)

Liu, Kexin; Zhang, Lijun; Hu, Shanshan; Xing, Jichuan; Li, Ping'an

2018-01-01

This paper demonstrated a compact white light transmitting antenna based on four-color VLC system, which included an integrating rod and a Fresnel lens system. This paper mainly analyzed the homogenizer: the hexagon integrating rod. After simulation and optimizing, the size of this rod is designed as 60mm (length) x 4.35mm (D). As a result of experiments, this antenna which mixes RGBY-LEDs' beam into white light with high uniformity (67.18%), and illuminate the area of 0.75m x 0.75m at 1.77m transmission distance. The color temperature of the detection surface is 5583K, the chromatic aberration is 0.0021, compared with light source E of standard illumination, less than eye solution (0.005). Also, we verified that this antenna could ensure a stable SNR in mobile communication.

Color picture drawings without form and eye movements: a case report of visual form agnosia in a girl.

Science.gov (United States)

Kaga, Kimitaka; Shindo, Mitsuko

2012-04-01

The case of an 8-year-old girl who manifested cortical blindness and whose color drawings of faces and objects were without outlines is reported. Her birth was uneventful. When she was 10 months old, she fell down to the floor from a chair, resulting in a subarachnoidal hemorrhage. A repeat brain MRI revealed localized lesions in the visual cortices in the right and left hemispheres. As she grew older she was found to have visual imperceptions. She was found to have difficulties in learning visually the names of objects with form and letters, and in recognizing faces of her family. However, she was able to discriminate well the colors of faces and objects and learn easily the names of the objects with form by touching. She seemed to utilize subcortical vision for seeing colors of faces and objects.

Eye Absence Does Not Regulate Planarian Stem Cells during Eye Regeneration.

Science.gov (United States)

LoCascio, Samuel A; Lapan, Sylvain W; Reddien, Peter W

2017-02-27

Dividing cells called neoblasts contain pluripotent stem cells and drive planarian flatworm regeneration from diverse injuries. A long-standing question is whether neoblasts directly sense and respond to the identity of missing tissues during regeneration. We used the eye to investigate this question. Surprisingly, eye removal was neither sufficient nor necessary for neoblasts to increase eye progenitor production. Neoblasts normally increase eye progenitor production following decapitation, facilitating regeneration. Eye removal alone, however, did not induce this response. Eye regeneration following eye-specific resection resulted from homeostatic rates of eye progenitor production and less cell death in the regenerating eye. Conversely, large head injuries that left eyes intact increased eye progenitor production. Large injuries also non-specifically increased progenitor production for multiple uninjured tissues. We propose a model for eye regeneration in which eye tissue production by planarian stem cells is not directly regulated by the absence of the eye itself. Copyright © 2017 Elsevier Inc. All rights reserved.

Colorism/Neo-Colorism

Science.gov (United States)

Snell, Joel

2017-01-01

There are numerous aspects to being non-Caucasian that may not be known by Whites. Persons of color suggest folks who are African, South Americans, Native Americans, Biracial, Asians and others. The question is what do these individuals feel relative to their color and facial characteristics. Eugene Robinson suggest that the future favorable color…

Eyes on the Skies 400 Years of Telescopic Discovery

CERN Document Server

Schilling, Govert

2011-01-01

Adopted as the official book of the International Year of Astronomy (IYA) 2009, this stunningly illustrated history of telescopic discovery spans the range from the first telescopes via the Hubble Space Telescope to next generation platforms, and how they have changed and continue to change our view of the universe, our place in it and where it all came from. Eyes on the Skies features numerous full-page photographs and is printed in high-quality color throughout. Also includes the official IYA DVD with 59 minutes of narrated text, expert comments and interviews, animations, computer simulatio

Luminance contours can gate afterimage colors and "real" colors.

Science.gov (United States)

Anstis, Stuart; Vergeer, Mark; Van Lier, Rob

2012-09-06

It has long been known that colored images may elicit afterimages in complementary colors. We have already shown (Van Lier, Vergeer, & Anstis, 2009) that one and the same adapting image may result in different afterimage colors, depending on the test contours presented after the colored image. The color of the afterimage depends on two adapting colors, those both inside and outside the test. Here, we further explore this phenomenon and show that the color-contour interactions shown for afterimage colors also occur for "real" colors. We argue that similar mechanisms apply for both types of stimulation.

A Complete Color Normalization Approach to Histopathology Images Using Color Cues Computed From Saturation-Weighted Statistics.

Science.gov (United States)

Li, Xingyu; Plataniotis, Konstantinos N

2015-07-01

In digital histopathology, tasks of segmentation and disease diagnosis are achieved by quantitative analysis of image content. However, color variation in image samples makes it challenging to produce reliable results. This paper introduces a complete normalization scheme to address the problem of color variation in histopathology images jointly caused by inconsistent biopsy staining and nonstandard imaging condition. Method : Different from existing normalization methods that either address partial cause of color variation or lump them together, our method identifies causes of color variation based on a microscopic imaging model and addresses inconsistency in biopsy imaging and staining by an illuminant normalization module and a spectral normalization module, respectively. In evaluation, we use two public datasets that are representative of histopathology images commonly received in clinics to examine the proposed method from the aspects of robustness to system settings, performance consistency against achromatic pixels, and normalization effectiveness in terms of histological information preservation. As the saturation-weighted statistics proposed in this study generates stable and reliable color cues for stain normalization, our scheme is robust to system parameters and insensitive to image content and achromatic colors. Extensive experimentation suggests that our approach outperforms state-of-the-art normalization methods as the proposed method is the only approach that succeeds to preserve histological information after normalization. The proposed color normalization solution would be useful to mitigate effects of color variation in pathology images on subsequent quantitative analysis.

Test-retest repeatability of the pupil light response to blue and red light stimuli in normal human eyes using a novel pupillometer

DEFF Research Database (Denmark)

Herbst, Kristina; Sander, Birgit; Milea, Dan

2011-01-01

In this study, we evaluated the repeatability of pupil responses to colored light stimuli in healthy subjects using a prototype chromatic pupillometer. One eye of 10 healthy subjects was tested twice in the same day using monochromatic light exposure at two selected wavelengths (660 and 470 nm......, we have developed a novel prototype of color pupillometer which demonstrates good repeatability in evoking and recording the pupillary response to a bright blue and red light stimulus....

Test-retest repeatability of the pupil light response to blue and red light stimuli in normal human eyes using a novel pupillometer

DEFF Research Database (Denmark)

Herbst, Kristina; Sander, Birgit; Milea, Dan

2011-01-01

In this study, we evaluated the repeatability of pupil responses to colored light stimuli in healthy subjects using a prototype chromatic pupillometer. One eye of 10 healthy subjects was tested twice in the same day using monochromatic light exposure at two selected wavelengths (660 and 470¿nm......, we have developed a novel prototype of color pupillometer which demonstrates good repeatability in evoking and recording the pupillary response to a bright blue and red light stimulus....

Using Single Colors and Color Pairs to Communicate Basic Tastes II: Foreground–Background Color Combinations

Science.gov (United States)

Marmolejo-Ramos, Fernando; Velasco, Carlos; Spence, Charles

2016-01-01

People associate basic tastes (e.g., sweet, sour, bitter, and salty) with specific colors (e.g., pink or red, green or yellow, black or purple, and white or blue). In the present study, we investigated whether a color bordered by another color (either the same or different) would give rise to stronger taste associations relative to a single patch of color. We replicate previous findings, highlighting the existence of a robust crossmodal correspondence between individual colors and basic tastes. On occasion, color pairs were found to communicate taste expectations more consistently than were single color patches. Furthermore, and in contrast to a recent study in which the color pairs were shown side-by-side, participants took no longer to match the color pairs with tastes than the single colors (they had taken twice as long to respond to the color pairs in the previous study). Possible reasons for these results are discussed, and potential applications for the results, and for the testing methodology developed, are outlined. PMID:27708752

Automated Detection and Differentiation of Drusen, Exudates, and Cotton-Wool Spots in Digital Color Fundus Photographs for Diabetic Retinopathy Diagnosis

NARCIS (Netherlands)

Niemeijer, M.; van Ginneken, B.; Russel, S.R.; Suttorp-Schulten, M.S.A.; Abràmoff, M.D.

2007-01-01

purpose. To describe and evaluate a machine learning-based, automated system to detect exudates and cotton-wool spots in digital color fundus photographs and differentiate them from drusen, for early diagnosis of diabetic retinopathy. methods. Three hundred retinal images from one eye of 300

Color constancy in 3D-2D face recognition

Science.gov (United States)

Meyer, Manuel; Riess, Christian; Angelopoulou, Elli; Evangelopoulos, Georgios; Kakadiaris, Ioannis A.

2013-05-01

Face is one of the most popular biometric modalities. However, up to now, color is rarely actively used in face recognition. Yet, it is well-known that when a person recognizes a face, color cues can become as important as shape, especially when combined with the ability of people to identify the color of objects independent of illuminant color variations. In this paper, we examine the feasibility and effect of explicitly embedding illuminant color information in face recognition systems. We empirically examine the theoretical maximum gain of including known illuminant color to a 3D-2D face recognition system. We also investigate the impact of using computational color constancy methods for estimating the illuminant color, which is then incorporated into the face recognition framework. Our experiments show that under close-to-ideal illumination estimates, one can improve face recognition rates by 16%. When the illuminant color is algorithmically estimated, the improvement is approximately 5%. These results suggest that color constancy has a positive impact on face recognition, but the accuracy of the illuminant color estimate has a considerable effect on its benefits.

Gaps in Current Knowledge and Priorities for Future Research in Dry Eye.

Science.gov (United States)

Saldanha, Ian J; Dickersin, Kay; Hutfless, Susan T; Akpek, Esen K

2017-12-01

Dry eye, a common yet underrecognized and evolving field, has few recommended treatment algorithms, mostly based on expert consensus rather than robust research evidence. There are high costs associated with managing dry eye and conducting research to identify effective and safe long-term treatments. To support evidence-based management of dry eye, our purpose was to identify and prioritize important clinical research questions for future clinical research. We translated recommendations from the American Academy of Ophthalmology's 2013 Preferred Practice Patterns for dry eye into answerable clinical research questions about treatment effectiveness. Clinicians around the world who manage patients with dry eye rated each question's importance from 0 (not important) to 10 (very important) using a 2-round online Delphi survey. We considered questions as "important" if ≥75% of respondents assigned a rating of 6 or more in round 2. We mapped the identified important clinical research questions to reliable systematic reviews published up to March 2016. Seventy-five clinicians from at least 21 countries completed both Delphi rounds. Among the 58 questions, 24 met our definition of "important": 9/24 and 7/24 addressed topical and systemic treatments, respectively. All 4 questions with the highest 25th percentiles addressed topical treatments. Although 6/24 "important" questions were associated with 4 existing reliable systematic reviews, none of these reviews came to a definitive conclusion about treatment effectiveness. We identified gaps pertaining to treatment options for dry eye. Future clinical research on the management of dry eye should strongly consider these prioritized questions.

Evaluating stream trout habitat on large-scale aerial color photographs

Science.gov (United States)

Wallace J. Greentree; Robert C. Aldrich

1976-01-01

Large-scale aerial color photographs were used to evaluate trout habitat by studying stream and streambank conditions. Ninety-two percent of these conditions could be identified correctly on the color photographs. Color photographs taken 1 year apart showed that rehabilitation efforts resulted in stream vegetation changes. Water depth was correlated with film density:...

Color adaptation induced from linguistic description of color.

Directory of Open Access Journals (Sweden)

Liling Zheng

Full Text Available Recent theories propose that language comprehension can influence perception at the low level of perceptual system. Here, we used an adaptation paradigm to test whether processing language caused color adaptation in the visual system. After prolonged exposure to a color linguistic context, which depicted red, green, or non-specific color scenes, participants immediately performed a color detection task, indicating whether they saw a green color square in the middle of a white screen or not. We found that participants were more likely to perceive the green color square after listening to discourses denoting red compared to discourses denoting green or conveying non-specific color information, revealing that language comprehension caused an adaptation aftereffect at the perceptual level. Therefore, semantic representation of color may have a common neural substrate with color perception. These results are in line with the simulation view of embodied language comprehension theory, which predicts that processing language reactivates the sensorimotor systems that are engaged during real experience.

In search of the rainbow: Colored inks in surgical pathology

Directory of Open Access Journals (Sweden)

Chandralekha Tampi

2012-01-01

Full Text Available Introduction: Although surgical pathologists are aware of the multiple advantages that coloured inks contribute to surgical pathology practice, these coloured inks are not available in India and importing them is not a viable proposition. A systematic search for locally available coloring agents was done, and resulted in identifying specific shades within a popular set of children′s hobby colors of a particular brand. They retain their bright distinct colors on paraffin blocks and sections. These paints are available all over India, and are cheap, safe, and easy to use. Coloring gross specimen excision margins with different colors, adds precision to margin examination. It allows three-dimensional microscopic reconstruction of the tumor vis-a-vis its various neighboring anatomic structures. It allows postoperative comparison of tissue planes predicted by preoperative imaging. It maintains orientation of grossed and dissected specimens, enabling the pathologist to re-visit the grossed specimen, if required, and confidently allows further sampling if necessary. Aim: A systematic search for indigenous coloring agents was carried out, which included the dyes used in the histopathology laboratory, gelatin, commercially available paints, including acrylic paints and inks. Results: The study identified specific shades within a brand of acrylic colors that are easily available and simple to use, with good results on microscopic examination. Conclusion: Colored inks lend precision to margin examination. A set of easily procurable colors are available in our country, which are easy to use, with distinct bright colors, safe, and reliable.

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...

Eyes Wide Open

Directory of Open Access Journals (Sweden)

Zoi Manesi

2016-04-01

Full Text Available Research from evolutionary psychology suggests that the mere presence of eye images can promote prosocial behavior. However, the “eye images effect” is a source of considerable debate, and findings across studies have yielded somewhat inconsistent support. We suggest that one critical factor may be whether the eyes really need to be watching to effectively enhance prosocial behavior. In three experiments, we investigated the impact of eye images on prosocial behavior, assessed in a laboratory setting. Participants were randomly assigned to view an image of watching eyes (eyes with direct gaze, an image of nonwatching eyes (i.e., eyes closed for Study 1 and averted eyes for Studies 2 and 3, or an image of flowers (control condition. Upon exposure to the stimuli, participants decided whether or not to help another participant by completing a dull cognitive task. Three independent studies produced somewhat mixed results. However, combined analysis of all three studies, with a total of 612 participants, showed that the watching component of the eyes is important for decision-making in this context. Images of watching eyes led to significantly greater inclination to offer help as compared to images of nonwatching eyes (i.e., eyes closed and averted eyes or images of flowers. These findings suggest that eyes gazing at an individual, rather than any proxy to social presence (e.g., just the eyes, serve as a reminder of reputation. Taken together, we conclude that it is “eyes that pay attention” that can lift the veil of anonymity and potentially facilitate prosocial behavior.

Shift Colors

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Publications & News Shift Colors Pages default Sign In NPC Logo Banner : Shift Colors Search Navy Personnel Command > Reference Library > Publications & News > Shift Colors Top Link Bar Navy Personnel Library Expand Reference Library Quick Launch Shift Colors Shift Colors Archives Mailing Address How to

Dry Eye Disease and Microbial Keratitis: Is There a Connection?

Science.gov (United States)

Narayanan, Srihari; Redfern, Rachel L.; Miller, William L.; Nichols, Kelly K.; McDermott, Alison M.

2013-01-01

Dry eye is a common ocular surface disease of multifactorial etiology characterized by elevated tear osmolality and inflammation leading to a disrupted ocular surface. The latter is a risk factor for ocular surface infection, yet overt infection is not commonly seen clinically in the typical dry eye patient. This suggests that important innate mechanisms operate to protect the dry eye from invading pathogens. This article reviews the current literature on epidemiology of ocular surface infection in dry eye patients and laboratory-based studies on innate immune mechanisms operating at the ocular surface and their alterations in human dry eye and animal models. The review highlights current understanding of innate immunity in dry eye and identifies gaps in our knowledge to help direct future studies to further unravel the complexities of dry eye disease and its sequelae. PMID:23583043

Peripheral Retinal Changes Associated with Age-Related Macular Degeneration in the Age-Related Eye Disease Study 2: Age-Related Eye Disease Study 2 Report Number 12 by the Age-Related Eye Disease Study 2 Optos PEripheral RetinA (OPERA) Study Research Group.

Science.gov (United States)

Domalpally, Amitha; Clemons, Traci E; Danis, Ronald P; Sadda, SriniVas R; Cukras, Catherine A; Toth, Cynthia A; Friberg, Thomas R; Chew, Emily Y

2017-04-01

To compare rates of peripheral retinal changes in Age-Related Eye Disease Study 2 (AREDS2) participants with at least intermediate age-related macular degeneration (AMD) with control subjects without intermediate age-related changes (large drusen). Cross-sectional evaluation of clinic-based patients enrolled in AREDS2 and a prospective study. Participants from prospective studies. The 200° pseudocolor and fundus autofluorescence (FAF) images were captured on the Optos 200 Tx Ultrawide-field device (Optos, Dunfermline, Scotland) by centering on the fovea and then steering superiorly and inferiorly. The montaged images were graded at a reading center with the images divided into 3 zones (zone 1 [posterior pole], zone 2 [midperiphery], and zone 3 [far periphery]) to document the presence of peripheral lesions. Peripheral retinal lesions: drusen, hypopigmentary/hyperpigmentary changes, reticular pseudodrusen, senile reticular pigmentary changes, cobblestone degeneration, and FAF abnormalities. A total of 484 (951 eyes) AREDS2 participants with AMD (cases) and 89 (163 eyes) controls without AMD had gradable color and FAF images. In zones 2 and 3, neovascularization and geographic atrophy (GA) were present, ranging from 0.4% to 6% in eyes of cases, respectively, and GA was present in 1% of eyes of controls. Drusen were detected in 97%, 78%, and 64% of eyes of cases and 48%, 21%, and 9% of eyes of controls in zones 2 and 3 superior and 3 inferior, respectively (P < 0.001 for all). Peripheral reticular pseudodrusen were seen in 15%. Senile reticular pigmentary change was the predominant peripheral change seen in 48% of cases and 16% of controls in zone 2 (P < 0.001). Nonreticular pigment changes were less frequent in the periphery than in the posterior pole (46% vs. 76%) and negligible in controls. Peripheral retinal changes are more prevalent in eyes with AMD than in control eyes. Drusen are seen in a majority of eyes with AMD in both the mid and far periphery, whereas

Natural Colorants: Food Colorants from Natural Sources.

Science.gov (United States)

Sigurdson, Gregory T; Tang, Peipei; Giusti, M Mónica

2017-02-28

The color of food is often associated with the flavor, safety, and nutritional value of the product. Synthetic food colorants have been used because of their high stability and low cost. However, consumer perception and demand have driven the replacement of synthetic colorants with naturally derived alternatives. Natural pigment applications can be limited by lower stability, weaker tinctorial strength, interactions with food ingredients, and inability to match desired hues. Therefore, no single naturally derived colorant can serve as a universal alternative for a specified synthetic colorant in all applications. This review summarizes major environmental and biological sources for natural colorants as well as nature-identical counterparts. Chemical characteristics of prevalent pigments, including anthocyanins, carotenoids, betalains, and chlorophylls, are described. The possible applications and hues (warm, cool, and achromatic) of currently used natural pigments, such as anthocyanins as red and blue colorants, and possible future alternatives, such as purple violacein and red pyranoanthocyanins, are also discussed.

Eye Movement Impairment Recovery in a Gaucher Patient Treated with Miglustat

Directory of Open Access Journals (Sweden)

Agostino Accardo

2010-01-01

Two sisters, presenting the same genotype (R353G/R353G, were diagnosed as suffering from GD; one of them later developed neurological alterations identified by quantitative saccadic eye movements analysis. The aim of the study was to quantitatively measure the miglustat effects in this GD neurological patient. Eye movement analysis during subsequent controls was performed by estimating the characteristic parameters of saccadic main sequence. The study demonstrates that the SRT alone can be effective in GD3. Moreover, it confirms that quantitative eye movement analysis is able to precociously identify also slight neurological alterations, permitting more accurate GD classification.

Do the Eyes Have It? Using Eye Tracking to Assess Students Cognitive Dimensions

Science.gov (United States)

Nisiforou, Efi A.; Laghos, Andrew

2013-01-01

Field dependence/independence (FD/FI) is a significant dimension of cognitive styles. The paper presents results of a study that seeks to identify individuals' level of field independence during visual stimulus tasks processing. Specifically, it examined the relationship between the Hidden Figure Test (HFT) scores and the eye tracking metrics.…

Objective evaluation of improvement in optic neuropathy following radiation therapy for thyroid eye disease

International Nuclear Information System (INIS)

Rush, Stephen; Winterkorn, Jacqueline; Zak, Rochelle

2000-01-01

Purpose: While the literature supports the use of radiation therapy for thyroid eye disease, it does not sufficiently describe in detail the results of radiation therapy for optic neuropathy associated with thyroid eye disease. The objective of this study is to quantify the changes in parameters of optic neuropathy after orbital irradiation for thyroid eye disease. Methods and Materials: Twelve consecutive patients with optic neuropathy from thyroid eye disease were followed by a single neuro-ophthalmology practice and treated by one radiation oncologist with radiation therapy from 1991 through 1995. All cases were prospectively followed for visual acuity, color vision, mean deviation, and/or foveal sensitivity and afferent pupillary defect. All patients received 2000 cGy in 10 fractions with megavoltage irradiation to the orbits. Results: Ten of 12 patients were evaluated for follow-up (one moved out of this country and one had a stroke, which confounded interpretation of examination results). An analysis was performed retrospectively while treatment and evaluation remained uniform. Five men and five women formed the basis of this study with a median age of 60 years (35-76 years). Nineteen eyes were evaluated for thyroid optic neuropathy. Improvement in optic nerve function occurred in eight of ten patients. Improvement was seen either during radiotherapy or within 2 weeks of completion. No long-term adverse effects were noted. Conclusion: This study objectively demonstrates improvement in optic neuropathy from radiation therapy for thyroid eye disease

Rationale for anti-inflammatory therapy in dry eye syndrome.

Science.gov (United States)

de Paiva, C S; Pflugfelder, S C

2008-01-01

Dry eye is a multifactorial condition that results in a dysfunctional lacrimal functional unit. Evidence suggests that inflammation is involved in the pathogenesis of the disease. Changes in tear composition including increased cytokines, chemokines, metalloproteinases and the number of T cells in the conjunctiva are found in dry eye patients and in animal models. This inflammation is responsible in part for the irritation symptoms, ocular surface epithelial disease, and altered corneal epithelial barrier function in dry eye. There are several anti-inflammatory therapies for dry eye that target one or more of the inflammatory mediators/pathways that have been identified and are discussed in detail.

Watermarking spot colors in packaging

Science.gov (United States)

Reed, Alastair; Filler, TomáÅ.¡; Falkenstern, Kristyn; Bai, Yang

2015-03-01

In January 2014, Digimarc announced Digimarc® Barcode for the packaging industry to improve the check-out efficiency and customer experience for retailers. Digimarc Barcode is a machine readable code that carries the same information as a traditional Universal Product Code (UPC) and is introduced by adding a robust digital watermark to the package design. It is imperceptible to the human eye but can be read by a modern barcode scanner at the Point of Sale (POS) station. Compared to a traditional linear barcode, Digimarc Barcode covers the whole package with minimal impact on the graphic design. This significantly improves the Items per Minute (IPM) metric, which retailers use to track the checkout efficiency since it closely relates to their profitability. Increasing IPM by a few percent could lead to potential savings of millions of dollars for retailers, giving them a strong incentive to add the Digimarc Barcode to their packages. Testing performed by Digimarc showed increases in IPM of at least 33% using the Digimarc Barcode, compared to using a traditional barcode. A method of watermarking print ready image data used in the commercial packaging industry is described. A significant proportion of packages are printed using spot colors, therefore spot colors needs to be supported by an embedder for Digimarc Barcode. Digimarc Barcode supports the PANTONE spot color system, which is commonly used in the packaging industry. The Digimarc Barcode embedder allows a user to insert the UPC code in an image while minimizing perceptibility to the Human Visual System (HVS). The Digimarc Barcode is inserted in the printing ink domain, using an Adobe Photoshop plug-in as the last step before printing. Since Photoshop is an industry standard widely used by pre-press shops in the packaging industry, a Digimarc Barcode can be easily inserted and proofed.

The HydroColor App: Above Water Measurements of Remote Sensing Reflectance and Turbidity Using a Smartphone Camera

Science.gov (United States)

Leeuw, Thomas; Boss, Emmanuel

2018-01-01

HydroColor is a mobile application that utilizes a smartphone’s camera and auxiliary sensors to measure the remote sensing reflectance of natural water bodies. HydroColor uses the smartphone’s digital camera as a three-band radiometer. Users are directed by the application to collect a series of three images. These images are used to calculate the remote sensing reflectance in the red, green, and blue broad wavelength bands. As with satellite measurements, the reflectance can be inverted to estimate the concentration of absorbing and scattering substances in the water, which are predominately composed of suspended sediment, chlorophyll, and dissolved organic matter. This publication describes the measurement method and investigates the precision of HydroColor’s reflectance and turbidity estimates compared to commercial instruments. It is shown that HydroColor can measure the remote sensing reflectance to within 26% of a precision radiometer and turbidity within 24% of a portable turbidimeter. HydroColor distinguishes itself from other water quality camera methods in that its operation is based on radiometric measurements instead of image color. HydroColor is one of the few mobile applications to use a smartphone as a completely objective sensor, as opposed to subjective user observations or color matching using the human eye. This makes HydroColor a powerful tool for crowdsourcing of aquatic optical data. PMID:29337917

Antireflective sub-wavelength structures for improvement of the extraction efficiency and color rendering index of monolithic white light-emitting diode

DEFF Research Database (Denmark)

Ou, Yiyu; Corell, Dennis Dan; Dam-Hansen, Carsten

2011-01-01

We have theoretically investigated the influence of antireflective sub-wavelength structures on a monolithic white light-emitting diode (LED). The simulation is based on the rigorous coupled wave analysis (RCWA) algorithm, and both cylinder and moth-eye structures have been studied in the work. Our...... simulation results show that a moth-eye structure enhances the light extraction efficiency over the entire visible light range with an extraction efficiency enhancement of up to 26 %. Also for the first time to our best knowledge, the influence of sub-wavelength structures on both the color rendering index...

A Discrete Model for Color Naming

Science.gov (United States)

Menegaz, G.; Le Troter, A.; Sequeira, J.; Boi, J. M.

2006-12-01

The ability to associate labels to colors is very natural for human beings. Though, this apparently simple task hides very complex and still unsolved problems, spreading over many different disciplines ranging from neurophysiology to psychology and imaging. In this paper, we propose a discrete model for computational color categorization and naming. Starting from the 424 color specimens of the OSA-UCS set, we propose a fuzzy partitioning of the color space. Each of the 11 basic color categories identified by Berlin and Kay is modeled as a fuzzy set whose membership function is implicitly defined by fitting the model to the results of an ad hoc psychophysical experiment (Experiment 1). Each OSA-UCS sample is represented by a feature vector whose components are the memberships to the different categories. The discrete model consists of a three-dimensional Delaunay triangulation of the CIELAB color space which associates each OSA-UCS sample to a vertex of a 3D tetrahedron. Linear interpolation is used to estimate the membership values of any other point in the color space. Model validation is performed both directly, through the comparison of the predicted membership values to the subjective counterparts, as evaluated via another psychophysical test (Experiment 2), and indirectly, through the investigation of its exploitability for image segmentation. The model has proved to be successful in both cases, providing an estimation of the membership values in good agreement with the subjective measures as well as a semantically meaningful color-based segmentation map.

Eye Tracking Metrics for Workload Estimation in Flight Deck Operation

Science.gov (United States)

Ellis, Kyle; Schnell, Thomas

2010-01-01

Flight decks of the future are being enhanced through improved avionics that adapt to both aircraft and operator state. Eye tracking allows for non-invasive analysis of pilot eye movements, from which a set of metrics can be derived to effectively and reliably characterize workload. This research identifies eye tracking metrics that correlate to aircraft automation conditions, and identifies the correlation of pilot workload to the same automation conditions. Saccade length was used as an indirect index of pilot workload: Pilots in the fully automated condition were observed to have on average, larger saccadic movements in contrast to the guidance and manual flight conditions. The data set itself also provides a general model of human eye movement behavior and so ostensibly visual attention distribution in the cockpit for approach to land tasks with various levels of automation, by means of the same metrics used for workload algorithm development.

High luminance monochrome vs. color displays: impact on performance and search

Science.gov (United States)

Krupinski, Elizabeth A.; Roehrig, Hans; Matsui, Takashi

2011-03-01

To determine if diagnostic accuracy and visual search efficiency with a high luminance medical-grade color display are equivalent to a high luminance medical-grade monochrome display. Six radiologists viewed DR chest images, half with a solitary pulmonary nodule and half without. Observers reported whether or not a nodule was present and their confidence in that decision. Total viewing time per image was recorded. On a subset of 15 cases eye-position was recorded. Confidence data were analyzed using MRMC ROC techniques. There was no statistically significant difference (F = 0.0136, p = 0.9078) between color (mean Az = 0.8981, se = 0.0065) and monochrome (mean Az = 0.8945, se = 0.0148) diagnostic performance. Total viewing time per image did not differ significantly (F = 0.392, p = 0.5315) as a function of color (mean = 27.36 sec, sd = 12.95) vs monochrome (mean = 28.04, sd = 14.36) display. There were no significant differences in decision dwell times (true and false, positive and negative) overall for color vs monochrome displays (F = 0.133, p = 0.7154). The true positive (TP) and false positive (FP) decisions were associated with the longest dwell times, the false negatives (FN) with slightly shorter dwell times, and the true negative decisions (TN) with the shortest (F = 50.552, p radiology.

Colors, colored overlays, and reading skills

Directory of Open Access Journals (Sweden)

Arcangelo eUccula

2014-07-01

Full Text Available In this article, we are concerned with the role of colors in reading written texts. It has been argued that colored overlays applied above written texts positively influence both reading fluency and reading speed. These effects would be particularly evident for those individuals affected by the so called Meares-Irlen syndrome, i.e. who experience eyestrain and/or visual distortions – e.g. color, shape or movement illusions – while reading. This condition would interest the 12-14% of the general population and up to the 46% of the dyslexic population. Thus, colored overlays have been largely employed as a remedy for some aspects of the difficulties in reading experienced by dyslexic individuals, as fluency and speed. Despite the wide use of colored overlays, how they exert their effects has not been made clear yet. Also, according to some researchers, the results supporting the efficacy of colored overlays as a tool for helping readers are at least controversial. Furthermore, the very nature of the Meares-Irlen syndrome has been questioned. Here we provide a concise, critical review of the literature.

Precision of Synesthetic Color Matching Resembles That for Recollected Colors Rather than Physical Colors

Science.gov (United States)

Arnold, Derek H.; Wegener, Signy V.; Brown, Francesca; Mattingley, Jason B.

2012-01-01

Grapheme-color synesthesia is an atypical condition in which individuals experience sensations of color when reading printed graphemes such as letters and digits. For some grapheme-color synesthetes, seeing a printed grapheme triggers a sensation of color, but "hearing" the name of a grapheme does not. This dissociation allowed us to…

Three genome-wide association studies and a linkage analysis identify HERC2 as a human iris color gene

NARCIS (Netherlands)

Kayser, Manfred; Liu, Fan; Janssens, A. Cecile J. W.; Rivadeneira, Fernando; Lao, Oscar; van Duijn, Kate; Vermeulen, Mark; Arp, Pascal; Jhamai, Mila M.; van Ijcken, Wilfred F. J.; den Dunnen, Johan T.; Heath, Simon; Zelenika, Diana; Despriet, Dominiek D. G.; Klaver, Caroline C. W.; Vingerling, Johannes R.; de Jong, Paulus T. V. M.; Hofman, Albert; Aulchenko, Yurii S.; Uitterlinden, Andre G.; Oostra, Ben A.; van Duijn, Cornelia M.

2008-01-01

Human iris color was one of the first traits for which Mendelian segregation was established. To date, the genetics of iris color is still not fully understood and is of interest, particularly in view of forensic applications. In three independent genome-wide association (GWA) studies of a total of

Why some colors appear more memorable than others: A model combining categories and particulars in color working memory.

Science.gov (United States)

Bae, Gi-Yeul; Olkkonen, Maria; Allred, Sarah R; Flombaum, Jonathan I

2015-08-01

Categorization with basic color terms is an intuitive and universal aspect of color perception. Yet research on visual working memory capacity has largely assumed that only continuous estimates within color space are relevant to memory. As a result, the influence of color categories on working memory remains unknown. We propose a dual content model of color representation in which color matches to objects that are either present (perception) or absent (memory) integrate category representations along with estimates of specific values on a continuous scale ("particulars"). We develop and test the model through 4 experiments. In a first experiment pair, participants reproduce a color target, both with and without a delay, using a recently influential estimation paradigm. In a second experiment pair, we use standard methods in color perception to identify boundary and focal colors in the stimulus set. The main results are that responses drawn from working memory are significantly biased away from category boundaries and toward category centers. Importantly, the same pattern of results is present without a memory delay. The proposed dual content model parsimoniously explains these results, and it should replace prevailing single content models in studies of visual working memory. More broadly, the model and the results demonstrate how the main consequence of visual working memory maintenance is the amplification of category related biases and stimulus-specific variability that originate in perception. (c) 2015 APA, all rights reserved).

A color magnetic vortex condensate in QCD

International Nuclear Information System (INIS)

Ambjoern, J.; Olesen, P.

1980-03-01

It is shown that there exists a very close analogy between a lattice of vorticies in a superconductor near the critical field and a condensate of color magnetic flux tubes due to the unstable mode in QCD. This analogy makes it possible to identify a dynamical Higgs field in QCD. It is shown that the color magnetic flux tubes are quantized in terms of the center group Z(2) in the SU(2) case. In the case of SU(N) it is possible to select a color direction of the field such that one has Z(N) quantization. (Auth.)

Multistabilities and symmetry-broken one-color and two-color states in closely coupled single-mode lasers.

Science.gov (United States)

Clerkin, Eoin; O'Brien, Stephen; Amann, Andreas

2014-03-01

We theoretically investigate the dynamics of two mutually coupled, identical single-mode semi-conductor lasers. For small separation and large coupling between the lasers, symmetry-broken one-color states are shown to be stable. In this case the light outputs of the lasers have significantly different intensities while at the same time the lasers are locked to a single common frequency. For intermediate coupling we observe stable symmetry-broken two-color states, where both lasers lase simultaneously at two optical frequencies which are separated by up to 150 GHz. Using a five-dimensional model, we identify the bifurcation structure which is responsible for the appearance of symmetric and symmetry-broken one-color and two-color states. Several of these states give rise to multistabilities and therefore allow for the design of all-optical memory elements on the basis of two coupled single-mode lasers. The switching performance of selected designs of optical memory elements is studied numerically.

Color Analysis

Science.gov (United States)

Wrolstad, Ronald E.; Smith, Daniel E.

Color, flavor, and texture are the three principal quality attributes that determine food acceptance, and color has a far greater influence on our judgment than most of us appreciate. We use color to determine if a banana is at our preferred ripeness level, and a discolored meat product can warn us that the product may be spoiled. The marketing departments of our food corporations know that, for their customers, the color must be "right." The University of California Davis scorecard for wine quality designates four points out of 20, or 20% of the total score, for color and appearance (1). Food scientists who establish quality control specifications for their product are very aware of the importance of color and appearance. While subjective visual assessment and use of visual color standards are still used in the food industry, instrumental color measurements are extensively employed. Objective measurement of color is desirable for both research and industrial applications, and the ruggedness, stability, and ease of use of today's color measurement instruments have resulted in their widespread adoption.

EyeGENE

Data.gov (United States)

U.S. Department of Health & Human Services — The eyeGENE® Biorepository and corresponding Database contain family history and clinical eye exam data from subjects enrolled in eyeGENE® Program coupled to...

Identifying the optical phenomena responsible for the blue appearance of veins

Science.gov (United States)

Van Leeuwen, Spencer R.; Baranoski, Gladimir V. G.

2017-09-01

Blue in nature is often associated with beauty. It can be observed all around us, from captivating blue eyes to iridescent blue butterfly wings. While colours in nature are often the result of pigmentation, the majority of natural blue is produced by structural coloration. The colour of the sky, for example, is primarily caused by Rayleigh scattering. In this paper, we examine a single occurrence of blue in nature, specifically the blue appearance of veins near the surface of human skin. The most comprehensive investigation of this coloration to date showed that it arises from a combination of the scattering properties of skin and the absorptance of venous blood. However, that work only considered broad optical properties of these mediums and did not identify the source of the colour. In this paper, we employ in silico experiments, performed using first-principles light interaction models for skin and blood, to investigate the net effect of skin and vein optical properties on their aggregate reflectance across the visible range. We show that the contribution of skin to the distinct appearance of veins primarily results from Rayleigh scattering occurring within the papillary dermis, a sublayer of the skin. The results of this paper, in addition to addressing an old open scientific question, may have practical implications for performing non-invasive measurements of the physiological properties of skin and blood.

The use of contrast-enhanced color doppler ultrasound in the differentiation of retinal detachment from vitreous membrane

International Nuclear Information System (INIS)

Han, Sang Suk; Chang, Seung Kook; Yoon, Jung Hee; Lee, Young Joon

2001-01-01

To compare the clinical utility of contrast-enhanced color Doppler US in the differentiation of retinal detachment (RD) from vitreous membrane (VM) with that of various conventional US modalities, and to analyze the enhancement patterns in cases showing an enhancement effect. In 32 eyes examined over a recent two-year period, RD (n=14) and VM (n=18) were confirmed by surgery (n=28) or clinical follow-up (n=4). In all cases, gray-scale, color Doppler, and power Doppler US were performed prior to contrast injection, and after the intravenous injection of Levovist (Schering, Berlin) by hand for 30 seconds at a dose of 2.5 g and a concentration of 300 mg/mL via an antecubital vein, contrast-enhanced color Doppler US was performed. At Doppler US, the diagnostic criterion for RD and VM was whether or not color signals were visualized in membranous structures. Diagnostic accuracy was 78% at gray-scale US, 81% at color Doppler US, 59% at power Doppler US, and 97% at contrast-enhanced color Doppler US. The sensitivity of color Doppler US to color signals in RD increased from 57% to 93% after contrast enhancement. The enhancement patterns observed were signal accentuation (n=3), signal extension (n=2), signal addition (n=3), and new signal visualization (n=5). Contrast-enhanced color Doppler US was the most accurate US modality for differentiating RD from VM, showing a significantly increased signal detection rate in RD

Bags Under Eyes

Science.gov (United States)

Bags under eyes Overview Bags under eyes — mild swelling or puffiness under the eyes — are common as you age. With aging, the tissues around your ... space below your eyes, adding to the swelling. Bags under eyes are usually a cosmetic concern and ...

An analysis of the BVRI colors of 22 active comets

Science.gov (United States)

Betzler, A. S.; Almeida, R. S.; Cerqueira, W. J.; Araujo, L. A.; Prazeres, C. J. M.; Jesus, J. N.; Bispo, P. A. S.; Andrade, V. B.; Freitas, Y. A. S.; Betzler, L. B. S.

2017-08-01

Our aim was to analyze the variation of Johnson-Kron-Cousins BVRI color indexes of a sample with 22 active comets of various dynamic groups with the time, geometrical, observational and dynamical parameters. We performed photometric observations of 16 comets between 2010 and 2014, using robotic telescopes in three continents. In addition to the sample, we used data of six comets available in the literature. A statistical comparison between the distributions of color indexes was performed using the Kruskal-Wallis H-test. The color indexes of active comets can vary a few tenths up to a magnitude on time scales that range from hours to weeks. Using the B-V colors of the observed comets, we generated a relationship that correlates the cometary visual and CCD magnitudes. We did not identify any relationship between B-V and V-R colors with heliocentric distance and phase angle. The color B-V is correlated with the photometric aperture that can be described by a logarithmic function. We did not identify any differences in the distribution of B-V color among the comets analyzed at a confidence level equal to or greater than 95%. The mean color of active comets are B-R = 1.20 ± 0.24 , B-V = 0.76 ± 0.16 and V-R = 0.42 ± 0.16 . Active comets with V-R colors outside the three standard deviation interval can be considered objects with unusual physical characteristics.

Color Memory

OpenAIRE

Pate, Monica; Raclariu, Ana-Maria; Strominger, Andrew

2017-01-01

A transient color flux across null infinity in classical Yang-Mills theory is considered. It is shown that a pair of test `quarks' initially in a color singlet generically acquire net color as a result of the flux. A nonlinear formula is derived for the relative color rotation of the quarks. For weak color flux the formula linearizes to the Fourier transform of the soft gluon theorem. This color memory effect is the Yang-Mills analog of the gravitational memory effect.

Animal Detection in Natural Images: Effects of Color and Image Database

Science.gov (United States)

Zhu, Weina; Drewes, Jan; Gegenfurtner, Karl R.

2013-01-01

The visual system has a remarkable ability to extract categorical information from complex natural scenes. In order to elucidate the role of low-level image features for the recognition of objects in natural scenes, we recorded saccadic eye movements and event-related potentials (ERPs) in two experiments, in which human subjects had to detect animals in previously unseen natural images. We used a new natural image database (ANID) that is free of some of the potential artifacts that have plagued the widely used COREL images. Color and grayscale images picked from the ANID and COREL databases were used. In all experiments, color images induced a greater N1 EEG component at earlier time points than grayscale images. We suggest that this influence of color in animal detection may be masked by later processes when measuring reation times. The ERP results of go/nogo and forced choice tasks were similar to those reported earlier. The non-animal stimuli induced bigger N1 than animal stimuli both in the COREL and ANID databases. This result indicates ultra-fast processing of animal images is possible irrespective of the particular database. With the ANID images, the difference between color and grayscale images is more pronounced than with the COREL images. The earlier use of the COREL images might have led to an underestimation of the contribution of color. Therefore, we conclude that the ANID image database is better suited for the investigation of the processing of natural scenes than other databases commonly used. PMID:24130744

Animal detection in natural images: effects of color and image database.

Directory of Open Access Journals (Sweden)

Weina Zhu

Full Text Available The visual system has a remarkable ability to extract categorical information from complex natural scenes. In order to elucidate the role of low-level image features for the recognition of objects in natural scenes, we recorded saccadic eye movements and event-related potentials (ERPs in two experiments, in which human subjects had to detect animals in previously unseen natural images. We used a new natural image database (ANID that is free of some of the potential artifacts that have plagued the widely used COREL images. Color and grayscale images picked from the ANID and COREL databases were used. In all experiments, color images induced a greater N1 EEG component at earlier time points than grayscale images. We suggest that this influence of color in animal detection may be masked by later processes when measuring reation times. The ERP results of go/nogo and forced choice tasks were similar to those reported earlier. The non-animal stimuli induced bigger N1 than animal stimuli both in the COREL and ANID databases. This result indicates ultra-fast processing of animal images is possible irrespective of the particular database. With the ANID images, the difference between color and grayscale images is more pronounced than with the COREL images. The earlier use of the COREL images might have led to an underestimation of the contribution of color. Therefore, we conclude that the ANID image database is better suited for the investigation of the processing of natural scenes than other databases commonly used.

Food colors: Existing and emerging food safety concerns.

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Oplatowska-Stachowiak, Michalina; Elliott, Christopher T

2017-02-11

Food colors are added to different types of commodities to increase their visual attractiveness or to compensate for natural color variations. The use of these additives is strictly regulated in the European Union, the United States, and many other countries worldwide. There is a growing concern about the safety of some commonly used legal food colorants and there is a trend to replace the synthetic forms with natural products. Additionally, a number of dyes with known or suspected genotoxic or carcinogenic properties have been shown to be added illegally to foods. Robust monitoring programs based on reliable detection methods are required to assure the food is free from harmful colors. The aim of this review is to present an up to date status of the various concerns arising from use of color additives in food. The most important food safety concerns in the field of food colors are lack of uniform regulation concerning legal food colors worldwide, possible link of artificial colors to hyperactive behavior, replacement of synthetic colors with natural ones, and the presence of harmful illegal dyes-both known but also new, emerging ones in food. The legal status of food color additives in the EU, United States, and worldwide is summarized. The reported negative health effects of both legal and illegal colors are presented. The European Rapid Alert System for Food and Feed notifications and US import alerts concerning food colors are analyzed and trends in fraudulent use of color additives identified. The detection methods for synthetic colors are also reviewed.

What Is Dry Eye?

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Full Text Available ... Español Eye Health / Eye Health A-Z Dry Eye Sections What Is Dry Eye? Dry Eye Symptoms ... Dry Eye Dry Eye Treatment What Is Dry Eye? Leer en Español: ¿Qué es el ojo seco? ...

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

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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.

Color Algebras

Science.gov (United States)

Mulligan, Jeffrey B.

2017-01-01

A color algebra refers to a system for computing sums and products of colors, analogous to additive and subtractive color mixtures. The difficulty addressed here is the fact that, because of metamerism, we cannot know with certainty the spectrum that produced a particular color solely on the basis of sensory data. Knowledge of the spectrum is not required to compute additive mixture of colors, but is critical for subtractive (multiplicative) mixture. Therefore, we cannot predict with certainty the multiplicative interactions between colors based solely on sensory data. There are two potential applications of a color algebra: first, to aid modeling phenomena of human visual perception, such as color constancy and transparency; and, second, to provide better models of the interactions of lights and surfaces for computer graphics rendering.

Enriching text with images and colored light

Science.gov (United States)

Sekulovski, Dragan; Geleijnse, Gijs; Kater, Bram; Korst, Jan; Pauws, Steffen; Clout, Ramon

2008-01-01

We present an unsupervised method to enrich textual applications with relevant images and colors. The images are collected by querying large image repositories and subsequently the colors are computed using image processing. A prototype system based on this method is presented where the method is applied to song lyrics. In combination with a lyrics synchronization algorithm the system produces a rich multimedia experience. In order to identify terms within the text that may be associated with images and colors, we select noun phrases using a part of speech tagger. Large image repositories are queried with these terms. Per term representative colors are extracted using the collected images. Hereto, we either use a histogram-based or a mean shift-based algorithm. The representative color extraction uses the non-uniform distribution of the colors found in the large repositories. The images that are ranked best by the search engine are displayed on a screen, while the extracted representative colors are rendered on controllable lighting devices in the living room. We evaluate our method by comparing the computed colors to standard color representations of a set of English color terms. A second evaluation focuses on the distance in color between a queried term in English and its translation in a foreign language. Based on results from three sets of terms, a measure of suitability of a term for color extraction based on KL Divergence is proposed. Finally, we compare the performance of the algorithm using either the automatically indexed repository of Google Images and the manually annotated Flickr.com. Based on the results of these experiments, we conclude that using the presented method we can compute the relevant color for a term using a large image repository and image processing.

What Is Dry Eye?

Medline Plus

Full Text Available ... Stories Español Eye Health / Eye Health A-Z Dry Eye Sections What Is Dry Eye? Dry Eye Symptoms ... of Dry Eye Dry Eye Treatment What Is Dry Eye? Leer en Español: ¿Qué es el ojo seco? ...

Heuristics and Criterion Setting during Selective Encoding in Visual Decision-Making: Evidence from Eye Movements.

Science.gov (United States)

Schotter, Elizabeth R; Gerety, Cainen; Rayner, Keith

2012-01-01

When making a decision, people spend longer looking at the option they ultimately choose compared other options-termed the gaze bias effect-even during their first encounter with the options (Glaholt & Reingold, 2009a, 2009b; Schotter, Berry, McKenzie & Rayner, 2010). Schotter et al. (2010) suggested that this is because people selectively encode decision-relevant information about the options, on-line during the first encounter with them. To extend their findings and test this claim, we recorded subjects' eye movements as they made judgments about pairs of images (i.e., which one was taken more recently or which one was taken longer ago). We manipulated whether both images were presented in the same color content (e.g., both in color or both in black-and-white) or whether they differed in color content and the extent to which color content was a reliable cue to relative recentness of the images. We found that the magnitude of the gaze bias effect decreased when the color content cue was not reliable during the first encounter with the images, but no modulation of the gaze bias effect in remaining time on the trial. These data suggest people do selectively encode decision-relevant information on-line.

Unique Temporal Expression of Triplicated Long-Wavelength Opsins in Developing Butterfly Eyes

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Kentaro Arikawa

2017-11-01

Full Text Available Following gene duplication events, the expression patterns of the resulting gene copies can often diverge both spatially and temporally. Here we report on gene duplicates that are expressed in distinct but overlapping patterns, and which exhibit temporally divergent expression. Butterflies have sophisticated color vision and spectrally complex eyes, typically with three types of heterogeneous ommatidia. The eyes of the butterfly Papilio xuthus express two green- and one red-absorbing visual pigment, which came about via gene duplication events, in addition to one ultraviolet (UV- and one blue-absorbing visual pigment. We localized mRNAs encoding opsins of these visual pigments in developing eye disks throughout the pupal stage. The mRNAs of the UV and blue opsin are expressed early in pupal development (pd, specifying the type of the ommatidium in which they appear. Red sensitive photoreceptors first express a green opsin mRNA, which is replaced later by the red opsin mRNA. Broadband photoreceptors (that coexpress the green and red opsins first express the green opsin mRNA, later change to red opsin mRNA and finally re-express the green opsin mRNA in addition to the red mRNA. Such a unique temporal and spatial expression pattern of opsin mRNAs may reflect the evolution of visual pigments and provide clues toward understanding how the spectrally complex eyes of butterflies evolved.

About the Eye

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Full Text Available ... Ask a Scientist Video Series Glossary The Visual System Your Eyes’ Natural Defenses Eye Health and Safety First Aid Tips Healthy Vision Tips Protective Eyewear Sports and Your Eyes Fun Stuff Cool Eye Tricks Links to More Information Optical Illusions Printables About the Eye Your eyes ...

Calculation of color difference and measurement of the spectrum of aerosol based on human visual system

Science.gov (United States)

Dai, Mengyan; Liu, Jianghai; Cui, Jianlin; Chen, Chunsheng; Jia, Peng

2017-10-01

In order to solve the problem of the quantitative test of spectrum and color of aerosol, the measurement method of spectrum of aerosol based on human visual system was proposed. The spectrum characteristics and color parameters of three different aerosols were tested, and the color differences were calculated according to the CIE1976-L*a*b* color difference formula. Three tested powders (No 1# No 2# and No 3# ) were dispersed in a plexglass box and turned into aerosol. The powder sample was released by an injector with different dosages in each experiment. The spectrum and color of aerosol were measured by the PRO 6500 Fiber Optic Spectrometer. The experimental results showed that the extinction performance of aerosol became stronger and stronger with the increase of concentration of aerosol. While the chromaticity value differences of aerosols in the experiment were so small, luminance was verified to be the main influence factor of human eye visual perception and contributed most in the three factors of the color difference calculation. The extinction effect of No 3# aerosol was the strongest of all and caused the biggest change of luminance and color difference which would arouse the strongest human visual perception. According to the sensation level of chromatic color by Chinese, recognition color difference would be produced when the dosage of No 1# powder was more than 0.10 gram, the dosage of No 2# powder was more than 0.15 gram, and the dosage of No 3# powder was more than 0.05 gram.

Eye Care Professionals' Perspectives on Eye Donation and an Eye Donation Registry for Research: A Single-Institution, Cross-Sectional Study.

Science.gov (United States)

Williams, Andrew M; Allingham, R Rand; Stamer, W Daniel; Muir, Kelly W

2016-06-01

A centralized eye donation registry for research could help to bridge the gap between patients interested in donating their eyes to science and scientists who conduct research on human eye tissue. Previous research has demonstrated patient and family support for such a registry. In this study, we assessed the views that eye care professionals have toward an eye donation registry for research. Surveys were distributed to all 46 clinical faculty members of the Duke University Eye Center. In addition to collecting demographic information, the surveys assessed clinicians' experience with discussing eye donation with patients, described the proposed eye donation registry for research and asked how the registry would affect the clinicians' practice. A total of 21 eye care professionals returned the survey. Thirty-three percent reported discussing eye donation with patients, and 43% reported that a patient has asked about donating their eyes for research on their disease. Eighty-six percent of eye care professionals reported that a centralized registry would improve the way they work with patients who express a desire to donate their eyes for research. The majority of eye care professionals at our academic institution indicated that an eye donation registry for research would improve how they work with patients who are interested in donating their eyes for research on their disease. Future research should examine how best to communicate this registry to ophthalmic patients.

Color-Blind Racism, Color-Blind Theology, and Church Practices

Science.gov (United States)

Hearn, Mark

2009-01-01

Color-blind racism develops when persons ignore color in people and see them simply as individuals. As persons of color in racialized societies such as the United States are unequally treated on account of their color, the issue becomes a matter of faith and religious experience as religious leaders and educators, who disregard color, overlook…

[A preliminary study on the color effect of IPS Empress all-ceramic veneers].

Science.gov (United States)

Li, Zhi-yong; Cheng, Xiang-rong; Wang, Yi-ning

2004-09-01

To evaluate the opaquing capacity, color compatibility and stability of IPS Empress all-ceramic veneers. A total of 86 IPS Empress all-ceramic veneers were made for 18 patients. The patients were divided into three groups: Group A was tetracycline teeth, 64 veneers for 5 patients; Group B was non-tetracycline teeth, 22 veneers for 13 patients; Group C was 22 natural vital teeth with normal color as control group. Before and after veneers were inserted, ShadeEye NCC was employed to obtain L * a * b * values of each tooth. The values of cemented veneers used as the baseline, the L * a * b * values of each veneer were measured half a year, 1 year, and 2 years after restoration respectively. All L * a * b * values at different evaluation times were analyzed by SPSS 10.0. Before and after veneers were restored, the L * a * b * values of both Group A and Group B were significantly different, the color difference being 5.01 and 4.15 respectively. The color difference between Group A and selected shade guides was 2.45. Compared with the baseline value, the L * value of Group A significantly decreased 2 years after restoration, but the DeltaE of different evaluation times was not significantly different. The color difference between Group B and Group C was 0.22 and there was no significant color difference after restoration. IPS Empress all-ceramic veneers have excellent opaquing capacity, color compatibility and stability to non-tetracycline teeth. To tetracycline teeth IPS Empress all-ceramic veneers have a certain opaquing capacity, but they cannot completely match with shade guides; the L * value is significantly different after restoration and further studies are needed to evaluate its color effect.

Multi-User Identification-Based Eye-Tracking Algorithm Using Position Estimation

Directory of Open Access Journals (Sweden)

Suk-Ju Kang

2016-12-01

Full Text Available This paper proposes a new multi-user eye-tracking algorithm using position estimation. Conventional eye-tracking algorithms are typically suitable only for a single user, and thereby cannot be used for a multi-user system. Even though they can be used to track the eyes of multiple users, their detection accuracy is low and they cannot identify multiple users individually. The proposed algorithm solves these problems and enhances the detection accuracy. Specifically, the proposed algorithm adopts a classifier to detect faces for the red, green, and blue (RGB and depth images. Then, it calculates features based on the histogram of the oriented gradient for the detected facial region to identify multiple users, and selects the template that best matches the users from a pre-determined face database. Finally, the proposed algorithm extracts the final eye positions based on anatomical proportions. Simulation results show that the proposed algorithm improved the average F1 score by up to 0.490, compared with benchmark algorithms.

Study On Technology Based Home Vision Screening And Creating Awareness On Eye Health

Directory of Open Access Journals (Sweden)

Nirav Mehta

2015-08-01

Full Text Available Introduction Technology is one of most important factor in todays life. IPAD is leading as people can make use of technology by just pressing buttons. Networking technology and education makes communication easier and helps people in easy education and awareness. Aim amp objectives The main aim of the study is to educate and aware among people regarding eye health and the check the visual function of their eye by using Apple I pad. Material and Methodology The following study is a home based vision screening program using IPAD which uses the basic tests like visual acuity color vision contrast sensitivity and amsler tests for checking the basic functions of the eye. The study was performed in many societies moving from one place to another using IPAD as a tool. Reliability of ipad was checked a pilot study on 25 subjects visual acuity colour vision and contrast sensitivity was taken on both ipad and Original chart like snellen ishihara and pellirobson and compared in which the results and the accuracy were same. The study also contains questionnaire on the awareness and education about eye health. The subjects included in the study were an age group of 10 to 70. Subjects like infants and blind were not included in the study. Results During the study it was observed that there is no significant difference in testing of visual acuity between ipad and Snellen standard chart. The subjects responded actively towards screening and that home vision screening can be possible. During the study it was found that 40 subjects out of 100 needed further detailed check-up and were referred in Rotary eye hospital hospital but only 3 out of 40 came for it. This shows that they are less aware and education about their eye health. Software used in IPAD were visual acuity color vision contrast sensitivity and amsler tests A questionnaire was also asked which indicated less awareness among the common people. Conclusion We examined with just an ipad and not an

Experimental Study on Color Durability of Color Asphalt Pavement

Science.gov (United States)

Ning, Shi; Huan, Su

2017-06-01

Aiming at the poor Color durability and the lack of research on Color asphalt pavement, spraying an anti-tire trace seal resin emulsion on the surface, a Color durable asphalt pavement was proposed. After long-term rolling and long-term aging test, the Color durability was evaluated by RGB function in Photoshop and trace residue rate formula. Test results proved that the Evaluation method was simple and effective. After long-term rolling, the Color of the road surface tends to a constant value. Spraying the emulsion on the road surface can resist tire traces. After long-term aging test, the resistance to tire traces was increased by 26.6% compared with the conventional type, while the former was 44.1% higher than the latter without long-term aging. The Color durable asphalt pavement can effectively improve the ability of Color asphalt pavement to resist tire traces, and significantly improve the Color durability of Color asphalt pavement.

A Discrete Model for Color Naming

Directory of Open Access Journals (Sweden)

J. M. Boi

2007-01-01

Full Text Available The ability to associate labels to colors is very natural for human beings. Though, this apparently simple task hides very complex and still unsolved problems, spreading over many different disciplines ranging from neurophysiology to psychology and imaging. In this paper, we propose a discrete model for computational color categorization and naming. Starting from the 424 color specimens of the OSA-UCS set, we propose a fuzzy partitioning of the color space. Each of the 11 basic color categories identified by Berlin and Kay is modeled as a fuzzy set whose membership function is implicitly defined by fitting the model to the results of an ad hoc psychophysical experiment (Experiment 1. Each OSA-UCS sample is represented by a feature vector whose components are the memberships to the different categories. The discrete model consists of a three-dimensional Delaunay triangulation of the CIELAB color space which associates each OSA-UCS sample to a vertex of a 3D tetrahedron. Linear interpolation is used to estimate the membership values of any other point in the color space. Model validation is performed both directly, through the comparison of the predicted membership values to the subjective counterparts, as evaluated via another psychophysical test (Experiment 2, and indirectly, through the investigation of its exploitability for image segmentation. The model has proved to be successful in both cases, providing an estimation of the membership values in good agreement with the subjective measures as well as a semantically meaningful color-based segmentation map.

Color blindness and interracial interaction: playing the political correctness game.

Science.gov (United States)

Norton, Michael I; Sommers, Samuel R; Apfelbaum, Evan P; Pura, Natassia; Ariely, Dan

2006-11-01

Two experiments explored the ramifications of endorsing color blindness as a strategy for appearing unprejudiced. In Study 1, Whites proved adept at categorizing faces on the basis of race, but understated their ability to do so. In Study 2, Whites playing the Political Correctness Game--a matching task that requires describing other individuals--were less likely to use race as a descriptor when paired with a Black partner than when paired with a White partner, a strategy that impaired communication and performance. In addition, avoidance of race was associated with Whites making less eye contact with and appearing less friendly toward Black partners.

Eye cosmetic usage and associated ocular comfort.

Science.gov (United States)

Ng, Alison; Evans, Katharine; North, Rachel; Purslow, Christine

2012-11-01

Eye cosmetics usage is commonplace and whilst some products such as eyeliner are applied with close proximity to the ocular surface, there is little knowledge of the short- and long-term ocular effects of eye cosmetic formulations. This study aimed to investigate the use of eye cosmetics and identify any relationships between ocular comfort and cosmetic usage. Results were collated from an online survey comprising 23 questions that recorded demographics, Ocular Surface Disease Index (OSDI) score, extent and range of eye cosmetic use and perceived comfort differences with and without eye cosmetics. The 1360 female respondents (median age 25, interquartile range 20-34 years) completed the survey; 83% reported using eye cosmetics regularly (≥ 3 times per week) with mascara being most commonly used. Fifty three per cent used at least three different eye cosmetics products regularly. OSDI scores of cosmetics users were similar to non-users (p = 0.083), but perceived comfort was greater when cosmetics were not used (p cosmetics users (use of products cosmetics were used. Median OSDI scores suggested a trend towards reduced comfort amongst eyeliner users (p = 0.07) although frequency and type of cosmetic products used did not appear to influence OSDI scores. This study shows the use of multiple eye cosmetics is extensive and associated with the perception of ocular discomfort. With such widespread use of these products, more research is required to assess the effect on the ocular surface and tear film, which may be underestimated. Ophthalmic & Physiological Optics © 2012 The College of Optometrists.

Individual Differences in Search and Monitoring for Color Targets in Dynamic Visual Displays.

Science.gov (United States)

Muhl-Richardson, Alex; Godwin, Hayward J; Garner, Matthew; Hadwin, Julie A; Liversedge, Simon P; Donnelly, Nick

2018-02-01

Many real-world tasks now involve monitoring visual representations of data that change dynamically over time. Monitoring dynamically changing displays for the onset of targets can be done in two ways: detecting targets directly, post-onset, or predicting their onset from the prior state of distractors. In the present study, participants' eye movements were measured as they monitored arrays of 108 colored squares whose colors changed systematically over time. Across three experiments, the data show that participants detected the onset of targets both directly and predictively. Experiments 1 and 2 showed that predictive detection was only possible when supported by sequential color changes that followed a scale ordered in color space. Experiment 3 included measures of individual differences in working memory capacity (WMC) and anxious affect and a manipulation of target prevalence in the search task. It found that predictive monitoring for targets, and decisions about target onsets, were influenced by interactions between individual differences in verbal and spatial WMC and intolerance of uncertainty, a characteristic that reflects worry about uncertain future events. The results have implications for the selection of individuals tasked with monitoring dynamic visual displays for target onsets. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Verification of rapid method for estimation of added food colorant type in boiled sausages based on measurement of cross section color

Science.gov (United States)

Jovanović, J.; Petronijević, R. B.; Lukić, M.; Karan, D.; Parunović, N.; Branković-Lazić, I.

2017-09-01

During the previous development of a chemometric method for estimating the amount of added colorant in meat products, it was noticed that the natural colorant most commonly added to boiled sausages, E 120, has different CIE-LAB behavior compared to artificial colors that are used for the same purpose. This has opened the possibility of transforming the developed method into a method for identifying the addition of natural or synthetic colorants in boiled sausages based on the measurement of the color of the cross-section. After recalibration of the CIE-LAB method using linear discriminant analysis, verification was performed on 76 boiled sausages, of either frankfurters or Parisian sausage types. The accuracy and reliability of the classification was confirmed by comparison with the standard HPLC method. Results showed that the LDA + CIE-LAB method can be applied with high accuracy, 93.42 %, to estimate food color type in boiled sausages. Natural orange colors can give false positive results. Pigments from spice mixtures had no significant effect on CIE-LAB results.

What We Have Learned from Animal Models of Dry Eye

Science.gov (United States)

Stern, Michael E.; Pflugfelder, Stephen C.

2017-01-01

Animal models have proved valuable to investigate the pathogenesis of dry eye disease, identify therapeutic targets and the efficacy of candidate therapeutics for dry eye. Pharmacological inhibition of the lacrimal functional unit and exposure of the mouse eye to desiccating stress was found to activate innate immune pathways, promote dendritic cell maturation and initiate an adaptive T cell response to ocular surface antigens. Disease relevant mediators and pathways have been identified through use of genetically altered mice, specific inhibitors and adoptive transfer of desiccating stress primed CD4+ T cells to naïve recipients. Findings from mouse models have elucidated the mechanism of action of cyclosporine A and the rationale for developing lifitegrast, the two currently approved therapeutics in the US. PMID:28282318

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.

Keeping an eye on syphilis.

Science.gov (United States)

Ong, Daini; Bhardwaj, Gaurav; Ong, Jason; Chen, Marcus; Lim, Lyndell L

2017-06-01

The objective of this article was to alert general practitioners (GPs) to the increase in ocular syphilis in the context of a worsening epidemic of syphilis among men who have sex with men (MSM). This study used a retrospective case review of ocular syphilis cases that presented to the Royal Victorian Eye and Ear Hospital from January 2015 to August 2016. Twelve patients (19 eyes) were identified, including 11 males. The mean age was 35 years, and seven men were identified as MSM. Two men were diagnosed with human immunodeficiency virus (HIV) infection at presentation. Blurred vision (n = 10) and/or floaters (n = 9) were the most common presenting symptoms. All patients had uveitis as the manifestation of the ocular involvement; however, redness and pain were not universally reported. GPs should be alert to the possibility of ocular syphilis at the time of syphilis diagnosis, particularly among MSM. Urgent ophthalmic referral is required if the patient is found to have new onset visual symptoms.

Patterns of Eye Diseases in Children Visiting a Tertiary Teaching ...

African Journals Online (AJOL)

Background: About 19 million children worldwide live with visual impairments resulting from different ocular morbidities. This study aimed to identify the different causes of eye diseases in children visiting a tertiary eye centre at Jimma University Hospital. Methods: We conducted a retrospective review of charts of patients of ...

Melanin deposition ruled out as cause of color changes in the red-eared sliders (Trachemys scripta elegans).

Science.gov (United States)

Cao, Dainan; Gong, Shiping; Yang, Jiangbo; Li, Weiye; Ge, Yan; Wei, Yufeng

2018-03-01

Animal coloration primarily depends on the presence of pigments and the mixing ratio of eumelanin and pheomelanin. The color of red-eared slider's carapace varies with age, from an olive green to a yellow green, and then to a yellow brown in juveniles, generally. The purpose of the present study was to investigate whether this color change is related to the difference in melanin expression. Melanin deposition levels were examined in the carapace, skin, eye and muscle of the three color-types using hematoxylin and eosin staining. Moreover, the full-length coding sequence (CDS) of red-eared slider turtle melanin biosynthesis regulatory genes TYR, TYRP1, MITF and SLC24A5 were cloned, sequenced and quantitatively analyzed. Both histological view of melanin deposition and quantitative real-time PCR test of melanin-regulated gene expressions showed that there are significant differences among different tissues of red-eared slider, but no significant difference among different color-types, indicating that melanin deposition is not associated with ontogenetic color change in the carapace of red-eared slider. This study initially explore the melanin deposition and the mRNA expression of melanin biosynthesis regulatory genes in red-eared slider, which serve as a foundation for further insight into the pigmentation patterns and the mechanism of body color change in turtles. Copyright © 2017 Elsevier Inc. All rights reserved.

Eye Movement Disorders

Science.gov (United States)

... work properly. There are many kinds of eye movement disorders. Two common ones are Strabismus - a disorder ... in "crossed eyes" or "walleye." Nystagmus - fast, uncontrollable movements of the eyes, sometimes called "dancing eyes" Some ...

Tree Colors: Color Schemes for Tree-Structured Data.

Science.gov (United States)

Tennekes, Martijn; de Jonge, Edwin

2014-12-01

We present a method to map tree structures to colors from the Hue-Chroma-Luminance color model, which is known for its well balanced perceptual properties. The Tree Colors method can be tuned with several parameters, whose effect on the resulting color schemes is discussed in detail. We provide a free and open source implementation with sensible parameter defaults. Categorical data are very common in statistical graphics, and often these categories form a classification tree. We evaluate applying Tree Colors to tree structured data with a survey on a large group of users from a national statistical institute. Our user study suggests that Tree Colors are useful, not only for improving node-link diagrams, but also for unveiling tree structure in non-hierarchical visualizations.

Etiology, prevalence, and treatment of dry eye disease

OpenAIRE

Gayton, Johnny L

2009-01-01

Johnny L GaytonEyesight Associates, Warner Robins, GA, USAPurpose: This review article examines the prevalence, etiology, and current therapies of dry eye disease, with special focus on postmenopausal women.Method: A systematic literature search utilizing MEDLINE was conducted to identify peer-reviewed articles related to dry eye published prior to September 2008. The terms “dry eye” and “women” were searched in combination with one or more of the follo...

Illuminant color estimation based on pigmentation separation from human skin color

Science.gov (United States)

Tanaka, Satomi; Kakinuma, Akihiro; Kamijo, Naohiro; Takahashi, Hiroshi; Tsumura, Norimichi

2015-03-01

Human has the visual system called "color constancy" that maintains the perceptive colors of same object across various light sources. The effective method of color constancy algorithm was proposed to use the human facial color in a digital color image, however, this method has wrong estimation results by the difference of individual facial colors. In this paper, we present the novel color constancy algorithm based on skin color analysis. The skin color analysis is the method to separate the skin color into the components of melanin, hemoglobin and shading. We use the stationary property of Japanese facial color, and this property is calculated from the components of melanin and hemoglobin. As a result, we achieve to propose the method to use subject's facial color in image and not depend on the individual difference among Japanese facial color.

Consistency and standardization of color in medical imaging: a consensus report.

Science.gov (United States)

Badano, Aldo; Revie, Craig; Casertano, Andrew; Cheng, Wei-Chung; Green, Phil; Kimpe, Tom; Krupinski, Elizabeth; Sisson, Christye; Skrøvseth, Stein; Treanor, Darren; Boynton, Paul; Clunie, David; Flynn, Michael J; Heki, Tatsuo; Hewitt, Stephen; Homma, Hiroyuki; Masia, Andy; Matsui, Takashi; Nagy, Balázs; Nishibori, Masahiro; Penczek, John; Schopf, Thomas; Yagi, Yukako; Yokoi, Hideto

2015-02-01

This article summarizes the consensus reached at the Summit on Color in Medical Imaging held at the Food and Drug Administration (FDA) on May 8-9, 2013, co-sponsored by the FDA and ICC (International Color Consortium). The purpose of the meeting was to gather information on how color is currently handled by medical imaging systems to identify areas where there is a need for improvement, to define objective requirements, and to facilitate consensus development of best practices. Participants were asked to identify areas of concern and unmet needs. This summary documents the topics that were discussed at the meeting and recommendations that were made by the participants. Key areas identified where improvements in color would provide immediate tangible benefits were those of digital microscopy, telemedicine, medical photography (particularly ophthalmic and dental photography), and display calibration. Work in these and other related areas has been started within several professional groups, including the creation of the ICC Medical Imaging Working Group.

Treatment of Sjögren's syndrome dry eye using 0.03% tacrolimus eye drop: Prospective double-blind randomized study.

Science.gov (United States)

Moscovici, Bernardo Kaplan; Holzchuh, Ricardo; Sakassegawa-Naves, Fernando Eiji; Hoshino-Ruiz, Diego Ricardo; Albers, Marcos Bottene Villa; Santo, Ruth Miyuki; Hida, Richard Yudi

2015-10-01

To describe the clinical efficacy of the treatment of Sjögren's syndrome dry eye using 0.03% tacrolimus eye drop. Prospective double-blind randomized study. Institutional outpatient clinic. Forty-eight eyes of twenty-four patients with dry eye related to Sjögren syndrome were enrolled in this study. The patients were randomized in 2 groups: tacrolimus (n=14) and vehicle (n=10) group. The tacrolimus group received a vial containing tacrolimus 0.03% (almond oil as vehicle) and the other group received the almond oil vehicle. All patients were instructed to use the eye drops every 12h in the lower conjunctival sac. Schirmer I test, break-up-time (BUT), corneal fluorescein and Rose Bengal staining scores were evaluated in all patients one day before the treatment (baseline), 7, 14, 28 and 90 days after treatment with the eye drops. The average fluorescein and Rose Bengal scores improved statistically after 7 days of treatment and even more after 90 days. The average Schirmer I and BUT values were unchanged after 7, 14 and 21 days but did show an improvement relative to baseline after 28 days of treatment. Schirmer I, BUT, fluorescein and Rose Bengal did not show any statistical significance in the vehicle group. Topical 0.03% tacrolimus eye drop improved tear stability and ocular surface status in cases of inflammatory or SS-related dry eye. ClinicalTrials.gov Identifier: NCT01850979. Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Exploring combinations of different color and facial expression stimuli for gaze-independent BCIs

Directory of Open Access Journals (Sweden)

Long eChen

2016-01-01

Full Text Available AbstractBackground: Some studies have proven that a conventional visual brain computer interface (BCI based on overt attention cannot be used effectively when eye movement control is not possible. To solve this problem, a novel visual-based BCI system based on covert attention and feature attention had been proposed and was called the gaze-independent BCI. Color and shape difference between stimuli and backgrounds have generally been used in examples of gaze-independent BCIs. Recently, a new paradigm based on facial expression change had been presented, and obtained high performance. However, some facial expressions were so similar that users couldn’t tell them apart. Especially they were presented at the same position in a rapid serial visual presentation (RSVP paradigm. Consequently, the performance of BCIs is reduced.New Method: In this paper, we combined facial expressions and colors to optimize the stimuli presentation in the gaze-independent BCI. This optimized paradigm was called the colored dummy face pattern. It is suggested that different colors and facial expressions could help subjects to locate the target and evoke larger event-related potentials (ERPs. In order to evaluate the performance of this new paradigm, two other paradigms were presented, called the grey dummy face pattern and the colored ball pattern. Comparison with Existing Method(s: The key point that determined the value of the colored dummy faces stimuli in BCI systems were whether dummy face stimuli could obtain higher performance than grey faces or colored balls stimuli. Ten healthy subjects (7 male, aged 21-26 years, mean 24.5±1.25 participated in our experiment. Online and offline results of four different paradigms were obtained and comparatively analyzed.Results: The results showed that the colored dummy face pattern could evoke higher P300 and N400 ERP amplitudes, compared with the grey dummy face pattern and the colored ball pattern. Online results showed

About the Eye

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Full Text Available ... for Kids >> About the Eye Listen All About Vision About the Eye Ask a Scientist Video Series ... Eye Health and Safety First Aid Tips Healthy Vision Tips Protective Eyewear Sports and Your Eyes Fun ...

About the Eye

Medline Plus

Full Text Available ... eye behind the iris that helps to focus light on the retina. It allows the eye to ... of the eye. It regulates the amount of light entering the eye through the pupil. Pupil (PYOO- ...

Plasmonic Metaparticles on a Blackbody Create Vivid Reflective Colors for Naked-Eye Environmental and Clinical Biodetection

DEFF Research Database (Denmark)

Elbahri, Mady; Abdelaziz, Moh eb; Homaeigohar, Shahin

2018-01-01

. A configuration of “Plasmonic metaparticles on a blackbody” is demonstrated and utilized for the design of a tailored perfect-colored absorber and for visual detection of environmental dielectrics that is not readily done by extinction plasmonics. Moreover, the Plasmonic Brewster Wavelength (PBW) effect...

Quantitative fundus autofluorescence in healthy eyes.

Science.gov (United States)

Greenberg, Jonathan P; Duncker, Tobias; Woods, Russell L; Smith, R Theodore; Sparrow, Janet R; Delori, François C

2013-08-21

Fundus autofluorescence was quantified (qAF) in subjects with healthy retinae using a standardized approach. The objective was to establish normative data and identify factors that influence the accumulation of RPE lipofuscin and/or modulate the observed AF signal in fundus images. AF images were acquired from 277 healthy subjects (age range: 5-60 years) by employing a Spectralis confocal scanning laser ophthalmoscope (cSLO; 488-nm excitation; 30°) equipped with an internal fluorescent reference. For each image, mean gray level was calculated as the average of eight preset regions, and was calibrated to the reference, zero-laser light, magnification, and optical media density from normative data on lens transmission spectra. Relationships between qAF and age, sex, race/ethnicity, eye color, refraction/axial length, and smoking status were evaluated as was measurement repeatability and the qAF spatial distribution. qAF levels exhibited a significant increase with age. qAF increased with increasing eccentricity up to 10° to 15° from the fovea and was highest superotemporally. qAF values were significantly greater in females, and, compared with Hispanics, qAF was significantly higher in whites and lower in blacks and Asians. No associations with axial length and smoking were observed. For two operators, between-session repeatability was ± 9% and ± 12%. Agreement between the operators was ± 13%. Normative qAF data are a reference tool essential to the interpretation of qAF measurements in ocular disease.

INFRARED COLOR-COLOR DIAGRAMS FOR AGB STARS

Directory of Open Access Journals (Sweden)

Kyung-Won Suh

2007-09-01

Full Text Available We present infrared color-color diagrams of AGB stars from the observations at near and mid infrared bands. We compile the observations for hundreds of OH/IR stars and carbon stars using the data from the Midcourse Space Experiment (MSX, the two micron sky survey (2MASS, and the IRAS point source catalog (PSC. We compare the observations with the theoretical evolutionary tracks of AGB stars. From the new observational data base and the theoretical evolution tracks, we discuss the meaning of the infrared color-color diagrams at different wavelengths.

Pattern of eye diseases among welders in a Nigeria community ...

African Journals Online (AJOL)

Background: Welders have been identified as a high risk group for eye disorders due to their exposure to ultraviolet radiation. Objective: To determine the prevalence and types of eye diseases amongst welders in Ile-Ife, Osun state. Methods: This is a cross sectional descriptive study of 405 consenting welders. Information ...

More to it than meets the eye: how eye movements can elucidate the development of episodic memory.

Science.gov (United States)

Pathman, Thanujeni; Ghetti, Simona

2016-07-01

The ability to recognise past events along with the contexts in which they occurred is a hallmark of episodic memory, a critical capacity. Eye movements have been shown to track veridical memory for the associations between events and their contexts (relational binding). Such eye-movement effects emerge several seconds before, or in the absence of, explicit response, and are linked to the integrity and function of the hippocampus. Drawing from research from infancy through late childhood, and by comparing to investigations from typical adults, patient populations, and animal models, it seems increasingly clear that eye movements reflect item-item, item-temporal, and item-spatial associations in developmental populations. We analyse this line of work, identify missing pieces in the literature and outline future avenues of research, in order to help elucidate the development of episodic memory.

Color digital halftoning taking colorimetric color reproduction into account

Science.gov (United States)

Haneishi, Hideaki; Suzuki, Toshiaki; Shimoyama, Nobukatsu; Miyake, Yoichi

1996-01-01

Taking colorimetric color reproduction into account, the conventional error diffusion method is modified for color digital half-toning. Assuming that the input to a bilevel color printer is given in CIE-XYZ tristimulus values or CIE-LAB values instead of the more conventional RGB or YMC values, two modified versions based on vector operation in (1) the XYZ color space and (2) the LAB color space were tested. Experimental results show that the modified methods, especially the method using the LAB color space, resulted in better color reproduction performance than the conventional methods. Spatial artifacts that appear in the modified methods are presented and analyzed. It is also shown that the modified method (2) with a thresholding technique achieves a good spatial image quality.

Diabetic Eye Disease

Science.gov (United States)

... Disease, & Other Dental Problems Diabetes & Sexual & Urologic Problems Diabetic Eye Disease What is diabetic eye disease? Diabetic eye disease is a group ... eye diseases that can threaten your sight are Diabetic retinopathy The retina is the inner lining at ...

Ultraviolet damage to the eye revisited: eye-sun protection factor (E-SPF®), a new ultraviolet protection label for eyewear

Science.gov (United States)

Behar-Cohen, Francine; Baillet, Gilles; de Ayguavives, Tito; Garcia, Paula Ortega; Krutmann, Jean; Peña-García, Pablo; Reme, Charlotte; Wolffsohn, James S

2014-01-01

Ultraviolet (UV) radiation potentially damages the skin, the immune system, and structures of the eye. A useful UV sun protection for the skin has been established. Since a remarkable body of evidence shows an association between UV radiation and damage to structures of the eye, eye protection is important, but a reliable and practical tool to assess and compare the UV-protective properties of lenses has been lacking. Among the general lay public, misconceptions on eye-sun protection have been identified. For example, sun protection is mainly ascribed to sunglasses, but less so to clear lenses. Skin malignancies in the periorbital region are frequent, but usual topical skin protection does not include the lids. Recent research utilized exact dosimetry and demonstrated relevant differences in UV burden to the eye and skin at a given ambient irradiation. Chronic UV effects on the cornea and lens are cumulative, so effective UV protection of the eyes is important for all age groups and should be used systematically. Protection of children’s eyes is especially important, because UV transmittance is higher at a very young age, allowing higher levels of UV radiation to reach the crystalline lens and even the retina. Sunglasses as well as clear lenses (plano and prescription) effectively reduce transmittance of UV radiation. However, an important share of the UV burden to the eye is explained by back reflection of radiation from lenses to the eye. UV radiation incident from an angle of 135°–150° behind a lens wearer is reflected from the back side of lenses. The usual antireflective coatings considerably increase reflection of UV radiation. To provide reliable labeling of the protective potential of lenses, an eye-sun protection factor (E-SPF®) has been developed. It integrates UV transmission as well as UV reflectance of lenses. The E-SPF® compares well with established skin-sun protection factors and provides clear messages to eye health care providers and to

Color preferences change after experience with liked/disliked colored objects.

Science.gov (United States)

Strauss, Eli D; Schloss, Karen B; Palmer, Stephen E

2013-10-01

How are color preferences formed, and can they be changed by affective experiences with correspondingly colored objects? We examined these questions by testing whether affectively polarized experiences with images of colored objects would cause changes in color preferences. Such changes are implied by the ecological valence theory (EVT), which posits that color preferences are determined by people's average affective responses to correspondingly colored objects (Palmer & Schloss, Proceedings of the National Academy of Sciences, 107, 8877-8882, 2010). Seeing images of strongly liked (and disliked) red and green objects, therefore, should lead to increased (and decreased) preferences for correspondingly colored red and green color patches. Experiment 1 showed that this crossover interaction did occur, but only if participants were required to evaluate their preferences for the colored objects when they saw them. Experiment 2 showed that these overall changes decreased substantially over a 24-h delay, but the degree to which the effect lasted for individuals covaried with the magnitude of the effects immediately after object exposure. Experiment 3 demonstrated a similar, but weaker, effect of affectively biased changes in color preferences when participants did not see, but only imagined, the colored objects. The overall pattern of results indicated that color preferences are not fixed, but rather are shaped by affective experiences with colored objects. Possible explanations for the observed changes in color preferences were considered in terms of associative learning through evaluative conditioning and/or priming of prior knowledge in memory.

No One Even Has Eyes: The Decline of Hand-Painted Graphics in Mumbai

Directory of Open Access Journals (Sweden)

Aaron Fine

2013-05-01

Full Text Available In this work of creative non-fiction, accompanied by coloring book plates of his own design, the author explores recent changes in Indian visual culture. An investigation of hand painted political graphics in Mumbai revealed very little painting and a great deal about the rapidly advancing digitalization of visual space in India. As idiosyncratic and individual creative efforts are replaced by mass-produced digital printing in what ways are India’s political networks enhanced; In what ways are India’s creative networks destroyed? Translators, police officers, political activists, and artists are presented through the eyes of an outsider whose own expectations about creative expression and political participation are challenged. The conclusion considers how once recycled visual culture artifacts are now junk destined for the landfill, and urges readers to color-in the whitewashed spaces of the city.

Influence of color word availability on the Stroop color-naming effect.

Science.gov (United States)

Kim, Hyosun; Cho, Yang Seok; Yamaguchi, Motonori; Proctor, Robert W

2008-11-01

Three experiments tested whether the Stroop color-naming effect is a consequence of word recognition's being automatic or of the color word's capturing visual attention. In Experiment 1, a color bar was presented at fixation as the color carrier, with color and neutral words presented in locations above or below the color bar; Experiment 2 was similar, except that the color carrier could occur in one of the peripheral locations and the color word at fixation. The Stroop effect increased as display duration increased, and the Stroop dilution effect (a reduced Stroop effect when a neutral word is also present) was an approximately constant proportion of the Stroop effect at all display durations, regardless of whether the color bar or color word was at fixation. In Experiment 3, the interval between the onsets of the to-be-named color and the color word was manipulated. The Stroop effect decreased with increasing delay of the color word onset, but the absolute amount of Stroop dilution produced by the neutral word increased. This study's results imply that an attention shift from the color carrier to the color word is an important factor modulating the size of the Stroop effect.

Transcriptome analysis of the exocarp of apple fruit identifies light-induced genes involved in red color pigmentation.

Science.gov (United States)

Vimolmangkang, Sornkanok; Zheng, Danman; Han, Yuepeng; Khan, M Awais; Soria-Guerra, Ruth Elena; Korban, Schuyler S

2014-01-15

Although the mechanism of light regulation of color pigmentation of apple fruit is not fully understood, it has been shown that light can regulate expression of genes in the anthocyanin biosynthesis pathway by inducing transcription factors (TFs). Moreover, expression of genes encoding enzymes involved in this pathway may be coordinately regulated by multiple TFs. In this study, fruits on trees of apple cv. Red Delicious were covered with paper bags during early stages of fruit development and then removed prior to maturation to analyze the transcriptome in the exocarp of apple fruit. Comparisons of gene expression profiles of fruit covered with paper bags (dark-grown treatment) and those subjected to 14 h light treatment, following removal of paper bags, were investigated using an apple microarray of 40,000 sequences. Expression profiles were investigated over three time points, at one week intervals, during fruit development. Overall, 736 genes with expression values greater than two-fold were found to be modulated by light treatment. Light-induced products were classified into 19 categories with highest scores in primary metabolism (17%) and transcription (12%). Based on the Arabidopsis gene ontology annotation, 18 genes were identified as TFs. To further confirm expression patterns of flavonoid-related genes, these were subjected to quantitative RT-PCR (qRT-PCR) using fruit of red-skinned apple cv. Red Delicious and yellow-skinned apple cv. Golden Delicious. Of these, two genes showed higher levels of expression in 'Red Delicious' than in 'Golden Delicious', and were likely involved in the regulation of fruit red color pigmentation. © 2013 Elsevier B.V. All rights reserved.

Diazo Printing of ERTS Color Composites

Science.gov (United States)

Mcmurtry, G. J.; Petersen, G. W. (Principal Investigator); Kowalik, W. S.

1975-01-01

The author has identified the following significant results. ERTS-1 color composites were made with the help of a Diazo developer and printer. Five single channel, density standards were established, using typical ERTS images, in order to determine exposure time. These standards were used to develop a graph from which the exposure time for any transparency can be estimated. Exposure times varied from 3 to 30 minutes, and clear colored polyester sheets from two manufactures were used with slightly different, but equally successful, results.

Pluto and Charon: Surface Colors and Compositions - A Hypothesis

Science.gov (United States)

Cruikshank, D. P.

2016-01-01

The surface of Pluto displays an array of colors ranging from yellow to red to brown, while the surface of Charon is largely gray with a north polar zone of red color similar to regions on Pluto. Pluto's surface shows layers of intensely colored material in tilted and transported blocks, and fractured geo-graphical units. This arrangement suggests episodes of formation or deposition of that material interspersed with episodes of emplacement of ices having little or no color. The ices identified on the surfaces of these two bodies (N2, CH4, CO, C2H6, H2O on Pluto, and H2O and NH3 on Charon) are colorless, as are nearly all ices in a powdery state. The colors on Pluto probably arise from the in situ formation of a macro-molecular carbonaceous material generated by energetic processing of the ices on the surface. Laboratory experiments producing refractory tholins particularly relevant to Pluto explored the chemistry of both UV and low-energy electron bombardment of a mix of Pluto ices (N2:CH4:CO = 100:1:1). We can term this Pluto ice tholin PIT. Water ice in the crystalline state characterizes Charon's surface, and while most of Charon's surface is neutral in color, with geometric albedo approximately 0.38, the polar zone and a light cover of fainter but similar reddish color over some surface regions suggest a common origin with the colored material on Pluto. NH3 or NH3 x nH2O was identified from disk-integrated Earth-based spectra, and a few concentrated NH3 exposures have been found in the New Horizons spectral images.

Representing Color Ensembles.

Science.gov (United States)

Chetverikov, Andrey; Campana, Gianluca; Kristjánsson, Árni

2017-10-01

Colors are rarely uniform, yet little is known about how people represent color distributions. We introduce a new method for studying color ensembles based on intertrial learning in visual search. Participants looked for an oddly colored diamond among diamonds with colors taken from either uniform or Gaussian color distributions. On test trials, the targets had various distances in feature space from the mean of the preceding distractor color distribution. Targets on test trials therefore served as probes into probabilistic representations of distractor colors. Test-trial response times revealed a striking similarity between the physical distribution of colors and their internal representations. The results demonstrate that the visual system represents color ensembles in a more detailed way than previously thought, coding not only mean and variance but, most surprisingly, the actual shape (uniform or Gaussian) of the distribution of colors in the environment.

Luminance contours can gate afterimage colors and 'real' colors

NARCIS (Netherlands)

Anstis, S.; Vergeer, M.L.T.; Lier, R.J. van

2012-01-01

It has long been known that colored images may elicit afterimages in complementary colors. We have already shown (Van Lier, Vergeer, & Anstis, 2009) that one and the same adapting image may result in different afterimage colors, depending on the test contours presented after the colored image. The

AFM study of structure influence on butterfly wings coloration

OpenAIRE

Dallaeva, Dinara; Tománek, Pavel

2012-01-01

This study describes the structural coloration of the butterfly Vanessa Atalanta wings and shows how the atomic force microscopy (AFM) can be applied to the study of wings morphology and wings surface behavior under the temperature. The role of the wings morphology in colors was investigated. Different colors of wings have different topology and can be identified by them. AFM in semi-contact mode was used to study the wings surface. The wing surface area, which is close to the butterfly body,...

What Is Dry Eye?

Science.gov (United States)

... Eye? Dry Eye Symptoms Causes of Dry Eye Dry Eye Treatment What Is Dry Eye? Leer en Español: ¿Qué ... Inside of Your Eyelid Nov 29, 2017 New Dry Eye Treatment is a Tear-Jerker Jul 21, 2017 Three ...

What Is Dry Eye?

Medline Plus

Full Text Available ... Eye Health A-Z Symptoms Glasses & Contacts Tips & Prevention News Ask an Ophthalmologist Patient Stories Español Eye ... Eye Symptoms Causes of Dry Eye Dry Eye Treatment What Is Dry Eye? Leer en Español: ¿Qué ...

AFM Study of Structure Influence on Butterfly Wings Coloration

Directory of Open Access Journals (Sweden)

Dinara Sultanovna Dallaeva

2012-01-01

Full Text Available This study describes the structural coloration of the butterfly Vanessa Atalanta wings and shows how the atomic force microscopy (AFM can be applied to the study of wings morphology and wings surface behavior under the temperature. The role of the wings morphology in colors was investigated. Different colors of wings have different topology and can be identified by them. AFM in semi-contact mode was used to study the wings surface. The wing surface area, which is close to the butterfly body, has shiny brown color and the peak of surface roughness is about 600 nm. The changing of morphology at different temperatures is shown.

Color-quality control using color-difference formulas: progress and problems

Science.gov (United States)

Melgosa, M.; Gómez-Robledo, L.; García, P. A.; Morillas, S.; Fernández-Maloigne, C.; Richard, N.; Huang, M.; Li, C.; Cui, G.

2017-08-01

We report on some recent advances in industrial color-difference evaluation focused in three main fields: Development of reliable experimental visual datasets; proposal of new color spaces and color-difference formulas; tools to evaluate the merits of color-difference formulas. The use of fuzzy techniques to assign consistency degrees to color pairs in combined visual datasets is described. The CIE/ISO joint proposal of the CIEDE2000 color-difference formula as a standard will facilitate the communication among companies and users. The CIE recommendation of the STRESS index to assess observers' variability and relative merits of different color-difference formulas is reported. Power functions are an efficient method to improve the performance of modern color-difference formulas. We need of advanced color-difference formulas accounting for new materials with different kind of textures and gonioapparent effects.

Characterization of Angle Dependent Color Travel of Printed Multi-Color Effect Pigment on Different Color Substrates

Directory of Open Access Journals (Sweden)

Mirica Karlovits

2015-03-01

Full Text Available Color-travel pigments, which exhibit much more extensive color change as well provide angle-dependent optical effect can be used in many industrial products. In present paper the multi-color effect pigment printed on three different foils with different background color (black, silver and transparent was investigated. The pigment was based on synthetically produced transparent silicon dioxide platelets coated with titanium dioxide. CIEL*a*b* values and reflection of prints were measured by multi-angle spectrophotometer at constant illumination at an angle of 45º and different viewing angles (-15º, 15°, 25º, 45º, 75º and 110º were used. The measurements of printed multi-color pigment showed that CIEL*a*b* color coordinates varied to great extents, depending on detection angles as well on color of the printing substrate. The study revealed that pigmnet printed on black background obtained significant change in color. The study has also shown that when viewing angle increases, the reflection curves decreases.

What Is Dry Eye?

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