Search PubMed⌕ Search

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.

At least 199 records · Page 11Linked to original sources
PubMedDate not supplied

Lanthony 15-Hue Desaturated Test for screening of early color vision defects in uncomplicated juvenile diabetes.

PURPOSE: To identify the most appropriate test for screening of early color vision abnormalities in uncomplicated juvenile diabetes. METHODS: Enrolled in this study were 39 diabetic adolescents, characterized by optimal Early Treatment Diabetic Retinopathy Study criteria for visual acuity, transparent dioptric means and angiographically normal retinas. Color vision was examined with Standard Pseudoisochromatic Plates (Part 2, SPP2), Roth 28-Hue Test (R28), Farnsworth-Munsell 100-Hue Tests (FM100), and Lanthony 15-Hue Desaturated Test (L15). Color confusion score (CCS) and desaturation angle (DSAT) were measured on L15 only. Thirty-nine normal subjects served as a control group. Poor metabolic control was an exclusion criteria. RESULTS: CCS was significantly higher in the patients than in the controls (37.8 +/- 11.1 vs 0 +/- P < .001) and normal scores were found in only 4 diabetic patients. DSAT values were spread, not showing a well-defined axis of the defect. The results of FM100 were clinically reliable but affected by a longer execution time. R28 and SPP2 demonstrated a low sensitivity, as all patients scored normally with both tests. CONCLUSIONS: Impaired color vision is a common observation even in patients with uncomplicated juvenile diabetes. Our results indicate that L15 is the most suitable test for screening of early color vision abnormalities in these subjects.

Adolescent↗
PubMedDate not supplied

Correlation of gene structure and psychophysical measurement in red-green color vision deficiency in Chinese.

PURPOSE: To study the correlation of genotype for X-linked red-green gene array with color vision phenotype in 58 subjects with red-green color vision deficiency. METHODS: The molecular structure of red and green pigment genes on 58 X chromosomes was studied exon-by-exon by using heteroduplex-SSCP analysis and sequencing. The color vision of these subjects was determined by a Neitz anomaloscope. RESULTS: Variations in the red and green pigment genes were detected in 43 subjects and a hybrid gene was found in 27 subjects. About 50% of the fusion sites occurred at intron 2-3. All 3 anomalous trichromats with intron 4 fusion were mild type but another 3 with intron 2-3 fusion were severe type. No subjects with mild type of color vision defects had a fusion site at intron 2-3 or its upstream. Three subjects with complete deletion of the green pigment gene manifested deuteranomaly. CONCLUSIONS: Protans can be differentiated from deutans on the basis of genotype. It is still difficult to establish a clear correlation of different anomalous trichromats with genotype. The fusion site of a hybrid gene affects the phenotype to some degree. Intron 2-3 is the common place for gene crossover.

Blotting, Southern↗
PubMed1987

Color vision defects in sickle cell anemia.

The Farnsworth-Munsell 100-hue test was used to compare color vision in patients with sickle cell anemia, 20/20 visual acuity, and mild to severe peripheral retinopathy, but without posterior retinal vessel involvement, with matched normal controls. Patients with sickle cell anemia had significantly more blue-yellow and mixed color vision defects and significantly higher Farnsworth-Munsell 100-hue scores than did controls. There were no significant associations between color vision defects and the severity of peripheral retinal findings or the diameter of the foveal avascular zone. These results suggest that color vision defects may exist in patients with sickle cell anemia in the absence of ophthalmoscopic retinal changes in the posterior fundus.

Adult↗
PubMed1985

The JLS lens: an aid for patients with color vision problems.

A device for helping color deficient patients has been developed. It utilizes an aqua tinted soft contact lens. Although the results have not yet undergone the appropriate scientific testing, these findings suggest that there are new developments that can help patients with color vision problems.

Color Perception↗
PubMed2005

Comparative use of color vision for frugivory by sympatric species of platyrrhines.

Ateles spp. and Alouatta spp. are often sympatric, and although they are mainly frugivorous and folivorous, respectively, they consume some of the same fruit species. However, they differ in terms of color vision, which is thought to be important for fruit detection. Alouatta spp. have routine trichromatic color vision, while Ateles spp. presents the classic polymorphism of platyrrhines: heterozygous females have trichromatic color vision, and males and homozygous females have dichromatic vision. Given these perceptual differences, one might expect Alouatta spp. to consume more reddish fruits than Ateles spp., since trichromats have an advantage for detecting fruits of that hue. Furthermore, since Ateles spp. have up to six different color vision phenotypes, as do most other platyrrhines, they might be expected to include fruits with a wider variety of hues in their diet than Alouatta spp. To test these hypotheses we studied the fruit foraging behavior of sympatric Alouatta palliata and Ateles geoffroyi in Costa Rica, and modeled the detectability of fruit via the various color vision phenotypes in these primates. We found little similarity in fruit diet between these two species (Morisita = 0.086). Furthermore, despite its polymorphism, A. geoffroyi consumed more reddish fruits than A. palliata, which consumed more greenish fruits. Our modeling results suggest that most fruit species included in the diet of A. geoffroyi can be discriminated by most color vision phenotypes present in the population. These findings show that the effect of polymorphism in platyrrhines on fruit detection may not be a disadvantage for frugivory. We suggest that routine trichromacy may be advantageous for other foraging tasks, such as feeding on young leaves.

Alouatta↗
PubMedDate not supplied

Color vision and occupational toluene exposure.

We examined the relationship between acquired color vision loss and exposure to toluene and total hydrocarbons among 125 male workers. Seventy-two toluene-exposed printers were compared with 34 workers from the same photogravure plant with ambient background exposure, and with 19 workers from a bookbinding plant located in the same town (nonexposed). Environmental mean toluene exposure level at workstation was estimated from individual 8-h sampling. Historic exposure data from the last 30 years were used to construct two cumulative exposure indices, one for toluene and one for total hydrocarbons. Airborne toluene levels were overall lower than the current Threshold Limit Value (TLV) of 50 ppm. Color vision was assessed by the Lanthony D-15 desaturated panel. Color vision loss was quantitatively established by the Color Confusion Index (CCI) and classified by type of acquired dyschromatopsia according to Verriest's classification. CCI was positively related to current airborne toluene levels, and cumulative exposure indices for toluene and total hydrocarbons (.18< or =r< or =.35). Odds ratios of acquired dyschromatopsia were significant for current airborne toluene, toluene, and total hydrocarbon past exposure (1.27 [1.02-1.58], 1.21 [1.04-1.39], 1.15 [1.02-1.31], respectively). In conclusion, this study suggests that the Lanthony D-15 desaturated panel detects early neurotoxic effects among workers exposed to toluene.

Adult↗
PubMed2005

Aviation-relevent epidemiology of color vision deficiency.

INTRODUCTION: The Colour Vision Study Group of Transport Canada undertook a prevalence review to ascertain the degree and type of color vision deficiency (CVD) common in different populations. This was performed as a first step toward establishing whether a bone fide occupational requirement for color vision in aviation can be determined. LITERATURE SEARCH: Peer-reviewed articles with large populations and appropriate methodology for measuring CVD were assessed. Those pertaining to congenital CVD were cross-sectional prevalence studies with greater than 100 subjects assessed with a combination of pseudoisochromatic plates (PIPs) and Farnsworth D15 and/or an anomaloscope. Of 162 papers reviewed, 36 met these criteria for inclusion in the congenital CVD section. Acquired CVD papers were included based on the quality of color vision tests employed. CONGENITAL CVD: Data on congenital and acquired CVD are presented separately in parts 1 and 2. Part 1 demonstrates that although the prevalence numbers for North American and European populations are consistent with those reported in reference texts, congenital CVD is actually less prevalent in Asian, African, and Native populations. Therefore, the reported overall 8% prevalence of CVD in men applies only to Euro-Caucasians and is significantly lower in other racial groups. Possible evolutionary implications of dichromatism in humans are explored. ACQUIRED CVD: In this section the current understanding of acquired color vision deficiency, with an estimated prevalence ranging from 5 to 15% (51,95), is reviewed. Acquired CVD is frequently associated with significant impairment of visual acuity and/or visual field. However, many ocular diseases and drugs do primarily affect color vision, independent of other visual function, and one must remain vigilant to their presence. CONCLUSION: Congenital CVD is present in a consequential percentage of men, but considerable variability exists in different populations (2-8%). Acquired CVD may elude detection, but if severe is also associated with loss of visual acuity and/or visual field. Senescence remains the most common and increasingly prevalent cause for acquired CVD.

Animals↗
PubMed1984

Color-vision mechanisms of the extrafoveal retina.

Wavelength discrimination, spectral sensitivity as well as color-matching performance were measured at the fovea and at different eccentricities in the peripheral retina. The results show that the underlying mechanisms of color vision in the normal peripheral retina are different from those of the classic forms of congenital color blindness. On the other hand, a close correspondence was found between color-vision characteristics obtained in the extrafoveal retina and in patients with acquired color-vision defects due to diseases of the optic nerve, suggesting that the loss of color discrimination with eccentricity and during progression of these diseases has a common underlying basis.

Color Perception↗
PubMed2006

The effect of decreased visual acuity on clinical color vision testing.

PURPOSE: Evaluate the effect of visual acuity on color vision testing. DESIGN: University based clinical experimental study. METHODS: Right eyes of 12 healthy subjects were fogged with plus lenses to logMAR 1.88 and assessed with D-15 panel, Ishihara, and Hardy-Rand-Rittler (HRR) plates. Subjects were tested at lesser degrees of fogging, 0.1 logMAR intervals. The acuity at which 5% of the population tests abnormally was estimated as follows. The average acuity at which a 10% reduction in correct responses occurred was determined. From this, two standard deviations were subtracted. Examination devices were compared using repeated measures analysis of variance. RESULTS: Color vision testing did not significantly differ from baseline up to logMAR 1.40 (D-15 panel), 1.10 (HRR plates), and 0.72 (Ishihara plates). Testing devices were significantly different (P < .005). CONCLUSIONS: Color vision testing is accurate up to logMAR 1.40 (20/501) with D-15 panel, 1.10 (20/252) with HRR plates, and 0.72 (20/106) with Ishihara plates.

Adult↗
PubMed1982

A survey and evaluation of lantern tests of color vision.

This paper reports a survey of the lantern tests that have been or are used to evaluate the color vision of people who wish to enter occupations that require the ability to recognize colored signal lights reliably. The origin of each lantern is traced and the principal features of each are described. The available data concerning failure rate of normals, the failure rate of people with defective color vision, and the extent to which scores on lantern tests correlate with field trials are summarized. Despite the fact that lantern tests have been used since the turn of the century and that some lanterns have been in use for more than 30 years and some for much longer periods, the available validation data are incomplete and sometimes conflicting. However, the data do indicate that some lanterns may fail a significant proportion of normals and that there is considerable variation between lanterns in the proportion of color vision defectives that will fail. It is noted that most lanterns will pass some protanomals despite their reduced sensitivity to red light and correspondingly short visual range for red signals. The view of Cameron is supported that a more rational approach would be to made a clinical diagnosis of the type of color vision defect, to reject protanopes, deuteranopes, and protanomals and to use a lantern test only to determine which deuteranomals should be accepted.

Aerospace Medicine↗
PubMed2000

Phylogenetic analysis and experimental approaches to study color vision in vertebrates.

To elucidate the molecular mechanisms of vertebrate color vision, it is essential to establish associations between amino acid substitutions and the directions of lambda max shifts of visual pigments. In this way, we can identify critical amino acid changes that may be responsible for lambda max shifts of visual pigments. In this process, we may consider only highly conserved residues, simply because the evolutionary conservation often implies functional importance. Using such an "evolutionary model" as a convenient tool in designing mutagenesis experiments, we can test specific hypotheses on the molecular mechanisms that are responsible for color vision in vertebrates. Virtually any vertebrate opsin cDNA can be expressed in COS cells, reconstituted with 11-cis-retinal, and the lambda max values of the regenerated pigments can be measured rather easily. By constructing mutant pigments with desired amino acid changes and conducting the in vitro assay and comparing their lambda max values with those of corresponding wild-type pigments, we can elucidate the molecular mechanisms of lambda max shifts--and color vision--of vertebrates rigorously.

Amino Acid Sequence↗
PubMed1998

Qualitative color vision impairment in toluene-exposed workers.

OBJECTIVE: The aim of this study was to evaluate whether toluene, like many other organic solvents and solvent mixtures, could impair color vision. SUBJECTS AND METHODS: We investigated color vision impairment in three groups of workers, two groups occupationally exposed to toluene and a nonexposed group. The first exposed group, group E1, comprised 41 workers (median value of toluene in air 35.00 ppm, range 11.3-49.3 ppm) and the second exposed group, group E2, comprised 32 subjects (median value of toluene in air 156.00 ppm, range 66.0-250.0 ppm). The nonexposed group, group NE, comprised 83 subjects. Color vision was evaluated by the Lanthony D-15 desaturated test according to Verriest's classification: type I, loss in the red-green range; type II, loss in the blue-yellow and red-green ranges, and type III, loss in the blue-yellow range. Subjects were classified as dyschromates if specific acquired loss was determined in at least one eye. In both exposed groups, exposure was evaluated by measurement of the concentration of toluene in the ambient air and in the blood. In group E2, level of hippuric acid and orthocresol in urine after the work shift were also determined. The Mann-Whitney U-test, t-test, chi 2-test, and Spearman's rank correlation and multiple regression analysis were used for statistical analysis. RESULTS: Type III dyschromatopsia was detected in all groups examined: 26.6% of the workers in group NE, 31.7% of those in group E1, and 50% of those in group E2. As many as 15.6% of the workers in group E2, 4.8% of those in group E1, and only 1.2% of those in group NE had type II dyschromatopsia. A statistically significant difference in the prevalence of total dyschromatopsia (type III + type II) was established among the three examined groups together (chi 2 = 14.13; df = 2; P < 0.01), between group E2 and group E1 (chi 2 = 4.96; P < 0.05), and between group E2 and group NE (chi 2 = 12.50; P < 0.005), whereas no significant difference was found between groups E1 and NE. Type III dyschromatopsia was significantly correlated with age in group NE (P < 0.01) and in group E1 (P < 0.005). In group E2, both type II (P < 0.05) and type III dyschromatopsia correlated with toluene in ambient air and with the duration of exposure to toluene (both P < 0.005). In group E2, total dyschromatopsia correlated significantly with toluene in ambient air and in blood (both P < 0.05) as well as with hippuric acid in urine after the work shift (P < 0.001). CONCLUSION: This study suggests that toluene can impair color vision.

Adult↗
PubMed1991

Deficiencies in human neonates' color vision: photoreceptoral and neural explanations.

Several photoreceptoral and neural models have been proposed to account for the development of human vision. To further evaluate those applicable to color vision, the present study examined 40 neonates' (mean age = 3.2 days) chromatic-achromatic discriminations in the mid-spectral region by using an habituation procedure and measures to minimize achromatic cues. Results indicated that newborns showed evidence of discriminating broad-band orange (lambda peak = 595 nm) but not yellow-green (lambda peak = 565 nm) lights from achromatic lights of varying luminance. Collectively, these and previous results imply that although newborns have at least dichromatic color vision, they possess relatively poor chromatic-achromatic discrimination in two spectral regions - in the short-wavelengths (including stimuli of 470-480 nm) and in the mid-wavelengths (including 565 nm). Although several hypotheses were considered, newborns' chromatic 'neutral zones' are best accounted for by models proposing that early color vision is limited by a general inefficiency of preneural (photoreceptoral and optical) mechanisms and/or by a selective immaturity of the SWS cones or the B/Y opponent channel.

Arousal↗
PubMed1984

Urinary glucose testing inaccuracies among diabetic patients. Effect of acquired color vision deficiency caused by diabetic retinopathy.

The performance of two urinary glucose tests (Clinitest and Diastix) and several color vision and lightness discrimination tests was assessed in 43 diabetic patients and 43 age-matched controls. Most of the diabetics had proliferative diabetic retinopathy, with normal or mildly reduced visual acuity. The diabetics made significantly more errors on color interpretation of the urinary test results than did controls. The extent of errors for both diabetics and controls correlated with the severity of color vision deficiency but not with lightness discrimination deficiency. The diabetics' performance of the Clinitest test and, to a lesser extent, of the Diastix test was significantly better in bright light than in dimmer light. The type of color vision deficiency among most of the diabetics was characteristic of the acquired blue-yellow defect associated with diabetes mellitus. All of the color vision tests enabled identification of patients likely to make a large number of urine-testing errors with high sensitivity and fairly high specificity.

Adult↗
PubMedDate not supplied

Multifocal and full-field electroretinogram changes associated with color-vision loss in mercury vapor exposure.

We evaluated the color vision of mercury-contaminated patients and investigated possible retinal origins of losses using electroretinography. Participants were retired workers from a fluorescent lamp industry diagnosed with mercury contamination (n = 43) and age-matched controls (n = 21). Color discrimination was assessed with the Cambridge Colour Test (CCT). Retinal function was evaluated by using the ISCEV protocol for full-field electroretinography (full-field ERG), as well as by means of multifocal electroretinography (mfERG). Color-vision losses assessed by the CCT consisted of higher color-discrimination thresholds along the protan, deutan, and tritan axes and significantly larger discrimination ellipses in mercury-exposed patients compared to controls. Full-field ERG amplitudes from patients were smaller than those of the controls for the scotopic response b-wave, maximum response, sum of oscillatory potentials (OPs), 30-Hz flicker response, and light-adapted cone response. OP amplitudes measured in patients were smaller than those of controls for O2 and O3. Multifocal ERGs recorded from ten randomly selected patients showed smaller N1-P1 amplitudes and longer latencies throughout the 25-deg central field. Full-field ERGs showed that scotopic, photopic, peripheral, and midperipheral retinal functions were affected, and the mfERGs indicated that central retinal function was also significantly depressed. To our knowledge, this is the first demonstration of retinal involvement in visual losses caused by mercury toxicity.

Adult↗
PubMed2001

Intervention study on acquired color vision deficiencies in styrene-exposed workers.

The main aim of the study was to examine the possible effects of occupational exposure to styrene on color vision function and the course after reduction of exposure. Color vision function was examined in 22 styrene-exposed laminators and 11 control subjects at a boat manufacturing plant. The Lanthony D-15 desaturated panel was used to test acquired dyschromatopsia. In all, six examinations were performed: Monday morning and Thursday afternoon of the same week, before and immediately after a vacation of 4 weeks (altogether, phase 1), and approximately 10 months later (phase 2), after the exposure level of styrene had been reduced. Styrene uptake was objectified by biological monitoring measuring the metabolites mandelic acid and phenylglyoxcylic acid in urine samples taken on Thursday afternoon. In both Thursday examinations, styrene-exposed workers had higher color confusion index (CCI) values compared with controls, which indicated quantitative color vision loss. After an exposure-free period of 4 weeks, a significant decrease of CCI values to normal range was found in laminators. Reexamination 10 months later showed also lower CCI values in exposed workers, indicating a dose-effect relationship. Abnormal CCI values occurred primarily in subjects with an excretion of approximately 500 to 600 mg mandelic acid plus phenylglyoxcylic acid per gram creatinine or more. We concluded that styrene-induced color vision dysfunction is reversible after an exposure-free interval of 4 weeks. The current Biological Tolerance Value of 600 mg mandelic acid plus phenylglyoxcylic acid per gram creatinine, as used in Germany, protects styrene-exposed workers from this subclinical effect.

Adult↗
PubMed2006

Color vision and macular recovery time in epileptic adolescents treated with valproate and carbamazepine.

Visual dysfunction has been reported in patients diagnosed with epilepsy. Some of these visual disturbances may be attributable to either the disease process, or the anticonvulsant therapy prescribed to control the seizures. The aims of our study were to evaluate whether color vision and macular function are impaired in epileptic adolescents, to study if the monotherapy with valproic acid (VPA) and carbamazepine (CBZ) can affect color vision and macular function and to determine the possible relationship between color vision, retinal function and antiepileptic drugs (AEDs) dosage and their serum concentrations. We examined 45 (16 male and 29 female, mean age +/- SD, 15.71 +/- 2.01 years) Caucasian epileptic patients suffering from various types of cryptogenic epilepsy before the beginning of therapy and after 1 year of VPA or CBZ monotherapy and 40 sex- and age-matched healthy controls. Color vision was assessed by Farnsworth Munsell (FM) 100-hue test and total error score (TES) was evaluated. This test consists of colored caps: the testee has to arrange the caps according to their colors macular function was assessed by nyctometry evaluating initial recovery time (IRT) and summation method (SM). This test evaluates visual acuity after a period of intense illumination of macula. Analysis of variance was used to evaluate the difference between controls and patients; moreover, Pearson's correlation test have been performed. Before the beginning of therapy, there were no differences in color vision and macular function between controls and epileptic patients. After 1 year, the patients, treated with VPA or CBZ, showed a deficit in FM 100-hue test. At nyctometry, all patients showed no significant variation of macular function between baseline evaluation and second evaluation at end of the follow-up. Our study demonstrates that, in our group of epileptic patients, epilepsy per se does not affect color vision and retinal function. In contrast, after 1 years of therapy with VPA and CBZ these patients showed a deficit in FM 100-hue test although nyctometry evaluation continued to be normal allowing to exclude an impairment in macular function. Further investigations are required to determine the pathophysiological alteration(s) that are at the basis of color perception defects.

Adolescent↗
PubMed1990

[The study of color vision in children].

The paper analyses results after investigation of color perception in 520 children (264 boys and 256 girls), aged 3-5 years, by means of two simple tests: a "Pflüger-Trident Test" (Velhagen) and a "Simplified Test of Color Vision" (Fletcher). It is proved that in children of under school age color perception is already developed enough and can be investigated for detecting disturbances in color vision.

Child, Preschool↗