[Investigations on the differential diagnosis of various forms of defective color vision with Trendelenburg's color-spot method].
Explore the source record for details and available documents.
Color↗
SEARCH · Search PubMed
Results for “COLOR VISION”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Testability of a color vision screening test in a population with mental retardation.
PURPOSE: The purpose of this study was to determine the testability of the "Co or Vision Testing Made Easy" color vision test, marketed as a screening test for young children, in a population of individuals with mental retardation. The test uses simple geometric figures that are easily identified. Previously, the test has demonstrated validity as a measure of color deficiency. METHODS: The test was presented to Special Olympic athletes, who are individuals with mental retardation or significant developmental delay, at four sites: the 1997 World Winter Games in Toronto, Canada; the Texas Summer Games in Houston, Texas; the Massachusetts Summer Games in Boston, Massachusetts; and Regional European Swim Competition in Seville, Spain. The criteria for passing was 8 correct responses on the first trial or 9 of 9 on the second attempt. RESULTS: Testability in Toronto, Canada; Houston, Texas; and Seville, Spain was high--95.5%, 98.7%, and 95.7%, respectively. Testability, however, dropped to 78.8% during the Boston, Massachusetts screening. There was no apparent difference in the testing environment that would account for the difference. The overall rate of testability was 93.2% for the 1078 athletes screened. The frequency of males identified as color deficient was similar to that expected in the general population; only two females (in Spain) failed the color vision screening. CONCLUSIONS: The "Color Vision Testing Made Easy" color vision test was successfully completed by a very high percentage of Special Olympics athletes. These results suggest that this test is useful in screening this population for color deficiencies, and that the prevalence of color vision deficiencies is approximately the same in individuals with mental retardation as in the general population.
Adolescent↗
Color vision and the four-color-map problem.
Four different colors are needed to make maps that avoid adjacent countries of the same color. Because the retinal image is two dimensional, like a map, four dimensions of chromatic experience would also be needed to optimally distinguish regions returning spectrally different light to the eye. We therefore suggest that the organization of human color vision according to four-color classes (reds, greens, blues, and yellows) has arisen as a solution to this logical requirement in topology.
Animals↗
Can color vision defective subjects who pass the farnsworth lantern test recognize surface color codes?
INTRODUCTION: The International Civil Aviation Organization requires that pilots be able to distinguish the colors used in air navigation and in particular be able to identify the colors of signal lights. Most national aviation authorities use a lantern test to assess the ability of applicants for a pilot's license who have abnormal color vision to recognize the colors of signal lights. However, color-coding is now widely used in aviation systems other than signal lights. Color is used in tarmac markings, maps, manuals, and electronic flight instrument displays. These color codes can use 10 or more colors, many more than the 3 to 5 used for signal lights. This study investigated whether people with defective color vision (DCV) who pass the Farnsworth lantern test can recognize the main colors used for surface color codes. METHODS: There were 99 subjects with DCV who were tested using the Optec 900 version of the Farnsworth lantern test and also named the colors of a set of 10 surface colors that varied in shape (dots and lines) and size (3 sizes; angular diameters 0.27, 1.0, and 2.4 degrees; angular widths 0.14, 0.27, and 0.50 degrees). A control group of 20 subjects with normal color vision also named the surface colors. RESULTS: Of the DCV subjects, 19% passed the Farnsworth lantern test, of whom 74% made no errors with the surface colors. The other 26% made few errors (up to 5 errors in 120 presentations) and those errors were mostly to confuse red, orange, and brown. The subjects with normal color vision made no errors naming the surface colors. CONCLUSION: Those who pass the Farnsworth lantern test can recognize the colors of a 10-color surface color code with few or no errors. This is because the small (2.9-min arc) stimulus of the lantern test presents a more difficult task than the larger surface colors.
Adolescent↗
The molecular basis of variation in human color vision.
Common variation in red-green color vision exists among both normal and color-deficient subjects. Differences at amino acids involved in tuning the spectra of the red and green cone pigments account for the majority of this variation. One source of variation is the very common Ser180Ala polymorphism that accounts for two spectrally different red pigments and that plays an important role in variation in normal color vision as well as in determining the severity of defective color vision. This polymorphism most likely resulted from gene conversion by the green-pigment gene. Another common source of variation is the existence of several types of red/green pigment chimeras with different spectral properties. The red and green-pigment genes are arranged in a head-to-tail tandem array on the X-chromosome with one red-pigment gene followed by one or more green-pigment genes. The high homology between these genes has predisposed the locus to relatively common unequal recombination events that give rise to red/green hybrid genes and to deletion of the green-pigment genes. Such events constitute the most common cause of red-green color vision defects. Only the first two pigment genes of the red/green array are expressed in the retina and therefore contribute to the color vision phenotype. The severity of red-green color vision defects is inversely proportional to the difference between the wavelengths of maximal absorption of the photopigments encoded by the first two genes of the array. Women who are heterozygous for red and green pigment genes that encode three spectrally distinct photopigments have the potential for enhanced color vision.
Color Perception↗
Recent advances in color vision research.
The remarkable variation in color vision both among and within primate species is receiving increasing attention from geneticists, psychophysicists, physiologists, and behavioral ecologists. It is known that color vision ability affects foraging behavior. Color vision is also likely to have implications for predation avoidance, social behavior, mate choice, and group dynamics, and should also influence the choice of stimuli for cognitive experiments. Therefore, understanding the color vision of a study species is important and of particular significance to scientists studying species with polymorphic color vision (most platyrrhines and some strepsirrhines). The papers in this issue were inspired by a symposium held during the 20th Congress of the International Primatological Society at Turin, Italy, in August 2004. The aim of the symposium was to bring together research from a range of disciplines, using recent methodological advances in molecular, modeling, and experimental techniques, to help elucidate the evolution, ecological importance, and distribution of color vision genotypes and phenotypes. The symposium achieved its aim, and as with most research in expanding disciplines, there are surprises and many questions still to be answered. Further advances will be made using a combination of different approaches involving analyses at the level of molecu1es, types of cell and neural networks, detailed and long-term field work, modeling, and carefully controlled experimentation.
Animals↗
Longitudinal cohort study of patients with birdshot chorioretinopathy II: color vision at baseline.
PURPOSE: To describe color vision at the baseline examination of 80 participants in a longitudinal cohort study of birdshot chorioretinopathy and to identify relationships between color vision and visual acuity, symptoms, and ophthalmic signs. DESIGN: Single center cross-sectional study. METHODS: Color vision was evaluated with the desaturated Lanthony 15-Hue test. Relationships were sought between the square root of the color confusion scores (CCS) and the following factors: best-corrected visual acuity (BCVA), symptoms, cataract, vitreous inflammatory reactions, retinal vasculitis, cystoid macular edema (CME), and birdshot lesion characteristics. RESULTS: When compared with published, age-matched normal control subjects, 49 patients (61.3%; 76 eyes [47.5%]) had abnormal CCS values. Abnormal CCS values were found in nine of 51 phakic eyes (18%) with normal BCVA (>or=1.0) and without cataract. Although most eyes did not have classifiable defects, 30 eyes (18.8%) had tritan (blue-yellow) defects (88% of eyes with classifiable defects). With the use of multivariate analyses, there were significant associations between increased CCS values and the symptoms of altered color vision (P = .005) and altered contrast sensitivity (P = .015). There was a significant, but weak, relationship between CCS values and birdshot lesion morphologic condition (P = .049), but no relationships were found with other lesion characteristics or with vitreous inflammatory reactions, retinal vasculitis, or CME. CONCLUSION: The Lanthony 15-Hue test provides an objective technique to assess complaints of altered color vision in people with birdshot chorioretinopathy. Color vision can be abnormal in eyes with normal visual acuity; therefore, this parameter may be useful as an additional measure for monitoring the disease.
Adult↗
[Congenital color vision deficiencies as a social problem].
Color vision standards for various occupations and schools have been greatly eased recently. However, if the trend is unaccompanied with proper advice for color defective persons, there is a risk of accidents such as occurred in the past when color vision standards had not been introduced, because the color vision defect is unchanged. In this context, the history of color vision standards and the color confusion by color defective persons in their daily life were reviewed. The collected data together with pathophysiological characteristics of defective color vision suggest that at least the following measures are necessary from a practical point of view: (1) By education and awareness, color defective persons can avoid errors in color in most cases. Therefore, ophthalmologists should inform them of their defects in childhood and give instructions on how to compensate for their disadvantages. (2) In public and occupational situations, all the information conveyed by color should include lettering or other forms of redundancy for the convenience of color defective persons.
Color Vision Defects↗
Effect of tinted contact lenses on color vision.
This study was designed to investigate the effects of various contact lens tints on color vision. Color vision performance of eight subjects was evaluated with the Farnsworth-Munsell 100 Hue Test while each subject wore each of 13 differently tinted contact lenses. No significant differences in color vision were found with the various lenses. However, performance on the test was affected by repetition. Regardless of the lens tints tested, color discrimination for the blue quadrant of the 100 Hue Test was the poorest. Further research is needed to determine the effect of tinted contact lenses on scotopic and mesopic vision.
Adult↗
Critical issues in the use and analysis of the Lanthony Desaturate Color Vision test.
The Lanthony Desaturate Color Vision test (D-15d) has been used to demonstrate the incidence of acquired color vision defects resulting from toxic exposure. The D-15d is a sensitive test designed to grade color deficiencies, but results can be difficult to interpret beyond the qualitative level, and the high incidence of errors reported for controls in some toxicology studies raises questions about how to effectively use this test. This article reviews standard administration of the test, physical determinants of performance, classification of acquired color vision defects, and methods of analysis that have been used to quantify results. The basis for a new method of analysis is discussed, illustrating the source of some characteristic errors, and recommendations are made for test protocols to attempt to more closely identify the type of color vision loss with the goal of identifying the site of toxicological insult.
Color Perception↗
More than three different cone pigments among people with normal color vision.
A fundamental feature of normal color vision is that red and green lights can be mixed to appear identical with a monochromatic yellow light. Another characteristic of normal color vision is that people often disagree on the amounts of red and green needed in the mixture to exactly match the yellow. Comparison of such color vision differences with photopigment gene differences reveals that a serine/alanine polymorphism at amino acid position 180 of X-encoded pigments can account for this type of color vision variation. This amino acid change shifts the spectrum of the pigment produced by about 6 nm, a value that would predict a larger minimum color vision difference between individuals than is actually observed. This discrepancy can be explained if, counter to the Young-Helmholtz theory as the explanation of trichromacy, many people with normal color vision have more than three spectrally different cone pigments.
Base Sequence↗
Infant color vision: prediction of infants' spontaneous color preferences.
Infants show spontaneous looking preferences among isoluminant chromatic stimuli [Adams, R. J. (1987). An evaluation of color preferences in early infancy. Infant Behavior and Development, 10, 143-150; Bornstein, M. H. (1975). Qualities of color vision in infancy. Journal of Experimental Social Psychology, 19 (3), 401-419.]. These differences in preference have often been called "hue" or "color" preferences, and attributed to differences in hue, but there are alternative explanations. Spontaneous preference variations remain after stimuli are equated for adult brightness, and thus cannot be attributed to adult-like brightness differences [Teller, D. Y., Civan, A., & Bronson-Castain, K. (2004). Infants' spontaneous color preferences are not due to adult-like brightness variations. Visual Neuroscience, 21 (3), 397-401]. In the present paper, we address three more alternative explanations: colorimetric purity; infant detection thresholds; and adult-like variations in saturation. Three experiments were conducted. In Experiment 1 we measured infants' spontaneous preferences for each of 22 different chromatic stimuli of varying dominant wavelength and colorimetric purity, each paired against the same white standard. In Experiment 2, we measured infants' chromatic detection thresholds. In Experiment 3, adult subjects made saturation matches between a blue-green standard and each of five other chromatic stimuli. Infant detection thresholds accounted for 34% of the variance in infant "hue" preferences, much more than colorimetric purity (2.4%) or adult saturation judgments (3%), but none of the three variables accounted for the majority of the variance. In our view, the most likely remaining option is that infants' spontaneous "hue" preferences indeed arise from preferences for the hues of stimuli that adults see as blue, purple and red.
Adult↗
Color vision: how the cortex represents color.
Our understanding of how we see color has benefited from the long tradition of visual psychophysics. More recently, models and methods from psychophysics are guiding modern neuroimaging experiments on color vision. Combining the two techniques can lead to discoveries that neither can make alone.
Cerebral Cortex↗
A quantitative scoring technique for panel tests of color vision.
Panel tests of color vision (eg FM100-Hue test) lack a common quantitative method for the scoring of cap arrangements. We describe a scoring method applicable to all panel tests that makes use of a novel technique to analyze test cap data, namely the calculation of a moment of inertia from the Color Difference Vectors (CDVs) of any arrangement pattern. Using the Farnsworth D-15 panel, as an example, we specify how to determine CDVs and demonstrate the benefits of calculating a moment of inertia for the analysis of these vectors. Moment of inertia analysis yields three factors which quantify cap arrangements: the first is the confusion angle which identifies the type of color defect; the second is the Confusion index (C-index) which quantifies the degree of color loss relative to a perfect arrangement of caps; and the third is the Selectivity index (S-index) which quantifies the amount of polarity or lack of randomness in a cap arrangement. A retrospective study on the result of 53 normal and 66 congenitally color defective observers is reported and provides normative data. We show that the technique differentiates between different types of color defect and provides useful clinical information regarding a loss of color vision. Likewise, a similar observation is made on a smaller sample of FM100-Hue results. A BASIC computer program is provided for anyone wishing to use the technique.
Adolescent↗
Color vision in diabetic school children.
The color vision of 64 diabetic school children was studied. Acquired color vision defects due to diabetes could not be found in any of the children. Two of the children had a congenital red-green color vision defect. In the examination, three different pseudoisochromatic plate tests (Isihara, Standard Pseudoisochromatic Plates part 2, and Lanthony Tritan Album) were used as well as the Nagel anomaloscope and three different cap arrangement tests (Panel D 15, Lanthony Desaturated Panel, and Farnsworth-Munsell 100 hue). The plate tests and the anomaloscope examination were fast, reliable, and well accepted by the children. The cap arrangement tests took more time, and many of the children neither liked nor properly performed these tests. Twelve color dependent glucose strip tests for diabetes care at home were also studied. A few of the youngest school children made mistakes in interpreting the colors of these strips, although their color vision was normal.
Adolescent↗
[Anomalous color vision and difficulty in color light perception].
Explore the source record for details and available documents.
Accident Prevention↗
Color vision: putting it together.
Color vision depends on the visual system comparing signals that originate in different classes of cone photoreceptors. New work shows that the different classes of cones are not only distributed irregularly, but in different individuals they are present in very variable proportions. Surprisingly, this does not affect color vision.
Animals↗
Color vision in dominant optic atrophy.
The color vision of seven patients with dominant optic atrophy in four different families was studied with the following color vision tests: the Standard Pseudoisochromatic Plates part 2, the Lanthony Tritan Album, the Velhagen Pflügertrident plates, and Farnsworth Panel D 15, the Farnsworth-Munsell 100 hue test, the Nagel anomaloscope, and the Besancon anomalometer. In the first family, the mother, one of the sons, and one of the grandsons were affected. The mother had a deutantritan defect; the son and the grandson both had an undefined red-green and a tritan defect. In the third family, the mother and the son were affected. Only the color vision of the son could be examined. He had a tritan defect. In the fourth family, the mother and the daughter were affected. Both had a deutan defect. In the diagnosis of dominant optic atrophy, it must be remembered that not only blue color vision defects occur, but that other kinds of defects are also possible.
Adult↗