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PubMed1994

[Effect of diffractive multi-focal lenses on contrast vision, glare sensitivity and color vision].

BACKGROUND: Due to theoretical considerations an increase in the depth of field of the diffractive IOL may be combined with a reduction in contrast sensitivity, glare sensitivity and colour perception. PATIENTS AND METHODS: A comparative analysis of both eyes was performed in ten patients with a diffractive multifocal IOL (3M 815LE) in one eye and a monofocal IOL in the other eye. Contrast sensitivity was examined by computer generated sine wave gratings of 6 different spatial frequencies; visual acuity with glare and glare sensitivity were determined under 7 different levels of field luminance; colour vision was examined using the Farnsworth-Munsell-100-Hue-test. RESULTS: Contrast sensitivity of the diffractive lens was reduced for intermediate spatial frequencies, but not for low and high frequencies. Visual acuity with glare was only reduced at maximum field luminance; no differences were found in glare sensitivity and colour perception between monofocal and multifocal. CONCLUSION: Altogether, the diffractive lens did not show a dramatic reduction in the examined visual functions compared with the monofocal IOL.

Aged↗
PubMed1989

What do color vision defectives say about everyday tasks?

A lengthy questionnaire was administered to 102 people with defective color vision and to an equal number of people with normal color vision. The questionnaire asked about the subjects' awareness of their defect and their knowledge of defective color vision as well as exploring the difficulties they experience with color at work and in pursuing leisure activities. The questionnaire was administered in the consulting room under conditions that might be expected to elicit frank replies. Nearly 90% of dichromats and up to two-thirds of anomalous trichomats reported difficulties with everyday tasks that involve color, nearly one-half of the dichromats and one in five anomalous trichromats reported difficulty with traffic lights, and similar proportions reported color difficulties in their present jobs. Substantial numbers reported that their color vision defect had affected their choice of career and many had been excluded from a chosen occupation. The screening of color vision in schools and provision of appropriate career counselling is urged.

Activities of Daily Living↗
PubMed2000

Detection of female carriers of congenital color-vision deficiencies by visual pigment gene analysis.

PURPOSE: Congenital color-vision deficiencies are frequent among males, 4.7-8.0%, suggesting that female carriers are present at a frequency of 9-15%. The purpose of this study was to determine whether carriers could be detected by analysis of the visual pigment genes. METHODS: DNA from 29 males with congenital color-vision deficiencies, from their mothers, and from 117 randomly-selected females was analyzed. The most upstream genes, the downstream genes, and the most downstream genes in the red/green pigment gene arrays were amplified separately by PCR. Exon 5 of each gene was analyzed by single-strand conformation polymorphisms (SSCP). RESULTS: Analysis of the visual pigment genes suggests that one of the 29 mothers examined is a female protan and two others are carriers of both protan and deutan defects. The remaining 26 mothers were confirmed to be carriers of congenital color-vision deficiencies. Unusual patterns were observed in 15 (13%) of the randomly-selected females; among them, 5 appeared to be protan carriers and at least 4 to be deutan carriers. CONCLUSIONS: Female carriers of congenital color-vision deficiencies can be detected by analysis of the visual pigment genes. Since the proportion of females showing unusual patterns was slightly higher than expected, some must be false-positives and require more detailed examination.

Color Perception↗
PubMed1997

Impaired color vision in cocaine-withdrawn patients.

BACKGROUND: The main reinforcing effect of cocaine happens by altering dopaminergic neurotransmission in the brain reward systems. Dopamine is found in high concentrations in the retina in which it plays an important role in color vision. Therefore, we investigated whether cocaine-dependent patients might have impaired color vision. METHODS: We compared patients recently withdrawn from cocaine (n = 31) with matched normal controls (n = 31) on 2 color vision tests. RESULTS: Cocaine-withdrawn patients had significantly higher error scores than matched controls on the Farnsworth-Munsell 100-hue and Lanthony desaturated D-15 color vision tests. Also, 23 of the 31 cocaine-withdrawn patients had blue-yellow color vision losses on the Farnsworth-Munsell 100-hue test compared with 3 controls (P < .001, chi 2 test) and 15 had blue-yellow color vision loss on the Lanthony desaturated D-15 test compared with 2 controls (P < .001, chi 2 test). CONCLUSIONS: These significantly higher test error scores and blue-yellow color vision losses suggest that color vision is impaired in cocaine-withdrawn patients. Color vision testing may be useful in future studies of cocaine-dependent patients.

Adult↗
PubMedDate not supplied

Color vision sensitivity in normally dichromatic species and humans.

Spectral-sensitivity functions for large, long-duration increments presented on a photopic white background indicate that wavelength-opponent mechanisms mediate detection in both normal and dichromatic humans. Normal humans exhibit high color-vision sensitivity as they discriminate the color of spectral flashes at detection-threshold intensities. However, dichromatic humans require stimuli up to about 0.4 log units above detection intensity to see certain colors. This low color-vision sensitivity in human dichromats may be an abnormal condition involving a defect in postreceptoral color processing. To test this hypothesis, we determined color-discrimination thresholds in normally dichromatic species: chipmunk, 13-lined ground squirrel, and tree shrew. For comparison, we also tested humans with normal and abnormal (deutan) color vision with the same apparatus and methods. Animals were trained to perform spatial two-choice discrimination tasks for food reward. Detection thresholds were determined for increments of white, 460 nm, 540 nm, 560 nm, 580 nm, 500 nm/long-pass, and 500 nm/short-pass on white backgrounds of 1.25 cd/m2, 46 cd/m2, and 130 cd/m2. Animals were also trained to respond to the colored increments when paired with the white increment when both were at equally detectable intensities. Color-discrimination thresholds were determined by dimming stimulus pairs (colored vs. white) until the subjects could no longer make the discriminations. Results indicated that the normally dichromatic species could discriminate colored stimuli from white at a mean intensity of 0.1 (+/-0.1) log units above detection threshold. The ability of normally dichromatic species to discriminate color near detection-threshold intensity is consistent with increment spectral-sensitivity functions that indicate detection by wavelength-opponent mechanisms. In keeping with previous studies, normal human trichromats discriminated color near detection-threshold intensities but humans with deutan color vision required suprathreshold intensities to discriminate the color of middle and long wavelengths. This high color-vision sensitivity of normally dichromatic species suggest that the low color-vision sensitivity in dichromatic humans is an abnormal condition and indicates a possible defect in their postreceptoral color-vision processing.

Animals↗
PubMedDate not supplied

Differences in color vision impairment caused by digoxin, digitoxin, or pengitoxin.

Color discrimination ability of 53 patients with congestive heart failure and 32 healthy volunteers treated with digoxin, digitoxin, or pengitoxin was determined with the Farnworth's Munsell 100 hue test. The patients had been treated with digitalis glycosides for several months prior to color vision testing. The volunteers received glycosides until a steady-state plasma concentration was reached. Glycoside plasma levels were measured by radioimmunoassay on the 3 days prior to color vision testing. The total error scores, indices of color discrimination, increased with the glycoside plasma levels. Subjects treated with digitoxin or pengitoxin exhibited no marked elevation in total error score at therapeutic concentrations, whereas 17 of 28 subjects with therapeutic digoxin plasma concentrations (less than 2.0 ng/ml) showed disturbed color discrimination. At toxic plasma levels all 5 digoxin-treated subjects, 7 of 13 digitoxin-treated subjects, and 3 of 8 pengitoxin-treated subjects showed impairment of color discrimination. The greater tendency of digoxin to impair color vision in comparison with digitoxin and pengitoxin may be related to a higher uptake or different distribution in the retina.

Acetyldigoxins↗
PubMed1990

[Early diagnosis of congenital disorders of color vision with the Velhagen "Pflügerhaken Color Charts for evaluating color perception" in 3,375 preschool children].

In three series of examinations, 3375 male preschool-age children and 93 adult normal trichromates were tested using the Velhagen Pflügerhaken charts. The authors recommend modifying the evaluation of the results slightly by introducing a "doubteful" category for children who make one mistake or who show hesitation and lack of assurance in interpreting the charts. Using this modified form of assessment, diagnoses of "probably achromatopic" and "doubtful" were made in 7.16% and 2.13% respectively of 1689 preschool-age boys. The failure rate during the test and the duration of the examination were age-dependent, and declined with increasing age from 4.15% to 0.45% and from 1.18 min to 0.59 min, respectively. Most mistakes were made with charts nos. 9, 3, and 5. The results of tests with Pflügerhaken charts are fully comparable with those of other internationally used tests for adults. They can be recommended for screening preschool-age children.

Adult↗
PubMed1997

Color vision of ancestral organisms of higher primates.

The color vision of mammals is controlled by photosensitive proteins called opsins. Most mammals have dichromatic color vision, but hominoids and Old World (OW) monkeys enjoy trichromatic vision, having the blue-, green-, and red-sensitive opsin genes. Most New World (NW) monkeys are either dichromatic or trichromatic, depending on the sex and genotype. Trichromacy in higher primates is believed to have evolved to facilitate the detection of yellow and red fruits against dappled foliage, but the process of evolutionary change from dichromacy to trichromacy is not well understood. Using the parsimony and the newly developed Bayesian methods, we inferred the amino acid sequences of opsins of ancestral organisms of higher primates. The results suggest that the ancestors of OW and NW monkeys lacked the green gene and that the green gene later evolved from the red gene. The fact that the red/green opsin gene has survived the long nocturnal stage of mammalian evolution and that it is under strong purifying selection in organisms that live in dark environments suggests that this gene has another important function in addition to color vision, probably the control of circadian rhythms.

Amino Acid Sequence↗
PubMedDate not supplied

Color vision testing to assist in diagnosis of digoxin toxicity.

This report describes an initial step in the process of determining whether color vision changes might form the basis for testing to assist in diagnosis of digoxin toxicity. The research questions concerned the types of color vision deficiencies found in people with elevated digoxin levels, the types of color vision tests that could help identify color vision changes in these people, and the relationship between serum digoxin level and subjects' responses to color vision tests. Three groups of subjects with a minimum of one week on maintenance digoxin therapy were tested. Two groups who were free of selected known causes of abnormal color vision participated in a single test session: clinic women (N = 19) and hospitalized women (N = 30). A third group (N = 10) was initially tested at a time of elevated serum digoxin levels (greater than or equal to 2.5 ng/ml) and retested at therapeutic levels. The Farnsworth-Munsell 100-Hue Test was performed on the clinic women. All subjects were tested with the Ishihara; the Hardy, Rand, and Rittler (HRR) plates; and the Farnsworth Panel D-15. The 49 women who had a single test session demonstrated a positive relationship between digoxin level and failing the Ishihara (p less than .05). On retest at therapeutic levels, the group with initial high digoxin levels had a significant reduction in the number of Ishihara (p .005) and HRR (p less than .005) errors. The Panel D-15 lacked sensitivity. Most subjects with high digoxin levels would not have been able to perform a reliable 100-Hue test. Red-green deficiency was the most common defect.

Adult↗
PubMed2000

Color vision defects after central serous chorioretinopathy.

PURPOSE: To reexamine patients diagnosed with central serous chorioretinopathy (CSC) during the 10-year period from 1987 to 1996 to identify remaining color vision defects in the eyes with normal visual acuity (VA). METHODS: Thirty-nine patients were found with normal VA of 20/20 (logMAR 0) or better 8 to 166 months (mean +/- SD, 58.8 +/- 41.2) after active CSC. Color vision was examined with the Standard Pseudoisochromatic Plates part 2, Farnsworth-Munsell 100 hue test, and Color Vision Meter 712 anomaloscope. RESULTS: Of the CSC eyes, 26 (67%) had a color vision defect, most of them in the blue area. There was no correlation between the time since the active disease and the results on the color vision tests. Of the contralateral eyes, 19 (49%) also had a color vision defect. CONCLUSION: In many patients some degree of color vision defect remains after CSC even if the VA has recovered to normal. The contralateral eye can also have a color vision defect. This has not been previously reported and might be due to earlier subclinical CSC.

Adult↗
PubMed2002

[A study on examination of color vision with pattern-visual evoked potential].

OBJECTIVE: To understand the specific nature of the color and brightness components of the human visual evoked potential and explore the possibility of an objective method for examining the color vision. METHOD: The transient VEP was measured in normal subjects and persons with deficient color vision by multichannel electro-physiological apparatus. In the experiment, four kinds of reversal checkerboard patterns are simulated by the computer software technology as stimuli. The patterns included black-white (95% contrast), isoluminance chromatic checkerboards red-white, green-white, red-green (100% saturation), which were 25 ' in visual angle and alternated at a rate of 0.8 Hz. The main component, P (1) wave, was analyzed. RESULTS: (1) The normal subject group: The P (1) latencies in four conditions were obtained in terms of the length of latencies, the ordinal of P (1) latencies (from short to long) was as follows: red-white < black-white < red-green < green-white. There were very significant differences among the four latencies (P < 0.01). The P (1) amplitudes elicited with the black-white were higher than those with chromatic ones. But among the P(1) amplitudes elicited with chromatic checkerboards there were no difference. (2) The group with deficient color vision: There were no significant differences in the P(1) latencies and amplitudes elicited with the four stimuli. The length of latencies with black- white stimulus was the shortest. Red-green blindness as well as deuteranopia had no response to green stimulus but did to red or red-green stimulus. (3) Between the two groups, there were no differences in the P (1) latencies, but the P (1) amplitudes of persons with deficient color vision elicited with the chromatic stimuli were obviously lower. CONCLUSION: The results show that it is feasible to use chromatic VEP for examining congenital color vision deficiency, especially for red-green blindness and deuteranopia. At present, there is lack of quantitative and qualitative results of color VEP examination.

Adolescent↗
PubMed2000

Color vision in epilepsy patients treated with vigabatrin or carbamazepine monotherapy.

PURPOSE: To investigate color vision in epilepsy patients treated with vigabatrin or carbamazepine monotherapy and to evaluate the association between vigabatrin-induced visual field defects and dyschromatopsia. DESIGN: Nonrandomized comparative trial. PARTICIPANTS: Thirty-two epilepsy patients treated with vigabatrin monotherapy, 18 patients treated with carbamazepine monotherapy, and 47 age-matched healthy controls were examined. MAIN OUTCOME MEASURES: Color vision was examined with Standard Pseudoisochromatic Plates 2 (SPP2) screening test, Farnsworth-Munsell 100 (FM 100) hue test, and Color Vision Meter 712 anomaloscope. RESULTS: Abnormal color perception was found in 32% of the epilepsy patients treated with vigabatrin monotherapy and 28% of the epilepsy patients treated with carbamazepine monotherapy. The total error score in the Farnsworth-Munsell 100 hue test was abnormally high in the vigabatrin monotherapy patients who had concentrically constricted visual fields and a statistically significant correlation was found between the temporal visual field extents and the age-adjusted Farnsworth-Munsell 100 total error score in vigabatrin monotherapy patients (R = .533, P = 0.003 in the right eye, R = .563, P = 0.001 in the left eye). Four of 31 (12%) vigabatrin monotherapy patients, and 1 of 18 (6%) carbamazepine monotherapy patients had a blue axis in Farnsworth-Munsell 100 hue test. In the anomaloscope, there were a few pathologic findings in both groups. In the SPP2 screening test, a few plates were not seen in both groups. CONCLUSIONS: Both examined antiepileptic drugs, vigabatrin and carbamazepine, cause acquired color vision defects. The abnormal color perception seems to be associated with constricted visual fields in the vigabatrin monotherapy patients. The duration of carbamazepine therapy correlates with high FM100 total error score. The best method for detecting dyschromatopsia in patients treated with vigabatrin or carbamazepine was the Farnsworth-Munsell 100 hue test. The SPP2 screening test does not seem to be useful in clinical practice.

Adult↗
PubMedDate not supplied

Abnormal color vision and reliable self-monitoring of blood glucose.

Color vision was assessed in 103 insulin-dependent diabetic patients using the Farnsworth-Münsell 100-Hue Test. All showed color vision impairment. Thirty-four had true dyschromatopsia while 22 suffered from tritanopia or other axial defects. We evaluated how accurately diabetic patients could monitor their own blood glucose by asking them to read a series of 30 precalibrated BM Test Glycemic Strips (Chemstrip, Boehringer, Mannheim, West Germany) without a meter. Patients with axial defects performed least well regardless of 100-Hue scores. Reading accuracy of patients with no axial defects was strongly correlated to 100-Hue scores, although patients having dyschromatopsia were consistently hesitant about their readings. Our results suggest that self-monitoring of blood glucose without a meter is indicated only after color vision has been examined by the 100-Hue Test. Self-monitoring should be voided with patients suffering from axial defects or having unsatisfactory 100-Hue scores.

Adult↗
PubMed1990

Molecular genetics of X chromosome-linked color vision among populations of African and Japanese ancestry: high frequency of a shortened red pigment gene among Afro-Americans.

Red-green color vision in humans is mediated by the X chromosome-linked highly homologous red and green pigment genes. Color vision defects are caused by deletions and fusions involving these genes. However, we found the frequency of molecular abnormalities among Caucasians to be twice as high as that of phenotypic color vision defects. Among Japanese the frequency of phenotypic and molecular color vision defects was similar (approximately 5%). Among Afro-Americans, molecular defects (largely green-red fusion genes) were at least five times more frequent (21%) than phenotypic color vision defects (approximately 4%). In addition, 35% of Afro-Americans, 2% of Japanese, and less than 1% of Caucasians had a shortened red pigment gene not associated with phenotypic color vision defects. This gene lacked 1.9 kilobases in its first intron and had the identical size as the green pigment gene from which it presumably originated by gene conversion in an ancestral African population. This gene and the closely linked glucose-6-phosphate dehydrogenase A+ variant were in linkage equilibrium. A model for the evolutionary origin of the color vision pigment genes in higher primates is portrayed.

Black People↗
PubMedDate not supplied

Color changes in the red-green plates of the 50-year-old AO HRR color vision test.

The original AO HRR color vision test has been considered by many as one of the best plate tests. It is still accepted by many governmental agencies for color vision certification. In their 1954 publication, Hardy, Rand, and Rittler stated that specially compounded inks were used for printing to avoid color changes with time. Fifty years later, it is both important and interesting to determine whether the wear and tear cause significant color changes. The chance finding of a never-used second edition offers an opportunity to evaluate the color changes. A GretagMacbeth Spectrolino spectrophotometer was used to measure the chromaticities of the never-used book, and an extensively used book. Four plates (#4, 7, 13, 16), selected randomly from the four red-green sections, were analyzed. The colored dots from each of the eight plates were plotted on a CIE chromaticity diagram. Isocolor lines were drawn to evaluate chromatic alignment. Chromaticities for plates #4 and 7 are significantly different between the two books. With regard to alignment with isocolor lines, the extensively used book is better than the never-used book for plate #4. There is significant misalignment on plate #7 for both books. Chromaticities for plates #13 and 16 are essentially identical between books, all with good alignment with isocolor lines. The overall comparison shows that the chromatic alignment characteristics of the extensively used book are not worse than the never-used book. Since colors in these plates have to be aligned with both the protan and deutan axes, any significant color changes would have disturbed this delicate requirement. The findings of many plates with good alignment, and the lack of differences on plates #13 and 16 between books, suggest that there are no significant color changes over time. Differences between books on plates #4 and 7 were likely the result of the original printing process.

Color↗
PubMed1988

Color vision defects in ocular hypertension and glaucoma. Quantification with a computer-driven color television system.

In order to detect early defects of color vision caused by increased intraocular pressure, a computer graphics device and color monitor system were used to measure color contrast sensitivity. The system determines the threshold chrominance of a colored grating in which there is no change in luminance. The study included 13 control subjects aged 10 to 57 years and 19 patients with ocular hypertension or glaucoma aged 20 to 58 years. In the 13 eyes with visual field loss, color contrast sensitivity was profoundly reduced when the grating colors fell on a tritan color confusion line. In the eyes without visual field loss, tritan color contrast sensitivity was reduced to an average level considerably below the extreme limits of the control group. These results were compared with those of other color vision tests and diagnostic criteria for glaucoma. The findings suggest that among the tests used, color contrast sensitivity testing was able to discriminate most effectively between patients who had retinal damage and the normal population.

Color Perception Tests↗