Effects of hypoxia on color vision with emphasis on the mesopic range

Barbur, John L.; Connolly, Desmond M.

doi:10.1586/eop.11.32

Cited by 15 publications

(33 citation statements)

References 49 publications

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“…In terms of cone-specific signal changes, the RG median standard CAD observer thresholds correspond to ∼0.75% and ∼0.4% Mand L-cone contrast, respectively. The YB median threshold, on the other hand, corresponds to ∼8% S-cone contrast [20]. The lower normal sensitivity for detection of yellow-blue changes may be due to the much reduced S-cone density in the retina [28], but when expressed in SN CAD units, the median thresholds correspond to one unit for both RG and YB discrimination.…”

Section: B Color Assessmentmentioning

confidence: 97%

“…Every subject was assessed for color vision using the Color Assessment and Diagnosis (CAD) test, which employs dynamic luminance contrast noise to isolate the use of color signals without affecting the subject's chromatic sensitivity [18,20]. The test stimuli were generated on a visual display (LaCie Electron Blue, 20 in.…”

Section: B Color Assessmentmentioning

confidence: 99%

“…The measurement procedure was described fully in earlier publications [20,27]. The CAD test has been employed in a number of previous studies that involved mostly young subjects, usually less than 50 years old, to examine how various parameters, such as the screen luminance, stimulus size, level of light adaptation of the eye, and stimulus eccentricity, affect chromatic sensitivity [19,20].…”

Section: B Color Assessmentmentioning

confidence: 99%

“…The CAD test has been employed in a number of previous studies that involved mostly young subjects, usually less than 50 years old, to examine how various parameters, such as the screen luminance, stimulus size, level of light adaptation of the eye, and stimulus eccentricity, affect chromatic sensitivity [19,20]. For convenience, the measurements are expressed in standard normal (SN) CAD units, which reflect the mean RG and YB thresholds measured in 330 normal trichromats [18].…”

Section: B Color Assessmentmentioning

confidence: 99%

“…When comparing color detection thresholds measured at lower light levels, it is therefore important to minimize the confounding effect of changes in retinal illuminance caused by differences in pupil size and prereceptoral absorption of light. Red-green (RG) and yellow-blue (YB) mechanisms act independently at threshold [20], but it is generally believed that aging affects preferentially the YB mechanism [21,22]. Although several studies have shown that color vision deteriorates with advancing age [23,24], some controversy remains as to whether normal aging affects more the YB mechanism [25].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Changes in color vision with decreasing light level: separating the effects of normal aging from disease

Barbur¹,

Konstantakopoulou²

2012

J. Opt. Soc. Am. A

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This is the unspecified version of the paper.This version of the publication may differ from the final published version. The purpose of this study was to obtain additional information about the health of the retina (HR) by measuring the rate of loss of chromatic sensitivity with decreasing light level. The HR index is introduced to separate the effects of normal aging from early stage disease. For normal subjects the HR index is largely independent of age (r 2 ∼ 0.1), but ∼11% of clinically normal, asymptomatic, older subjects exhibit values below the 2σ limit. The HR index provides a single number that captures how light level affects chromatic sensitivity irrespective of age and can be used to screen for preclinical signs of retinal disease. Permanent

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Section: B Color Assessmentmentioning

confidence: 97%

Section: B Color Assessmentmentioning

confidence: 99%

Section: B Color Assessmentmentioning

confidence: 99%

Section: B Color Assessmentmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Changes in color vision with decreasing light level: separating the effects of normal aging from disease

Barbur¹,

Konstantakopoulou²

2012

J. Opt. Soc. Am. A

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Color vision assessment‐3. An efficient, two‐step, color assessment protocol

Barbur

Rodriguez‐Carmona

Evans

2020

Color Research & Application

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Color vision tests and multi-test protocols in current use often fail to detect small changes in red/green (RG) and yellow/blue (YB) color vision due to poor sensitivity. The tests also have low specificity. In this study, we examine how improved understanding of within-and inter-subject variability in RG and YB color vision and accurate assessment of the differences in color thresholds between the least-sensitive, age-matched normal trichromats, and the leastaffected deutans and protans can be used to design an efficient color vision screener (CVS) test. To achieve this objective, we examined two extensive data sets from earlier studies and carried out new experiments to provide better estimates of within-subject variability in color thresholds and to validate the CVS test. The data sets provide essential information on inter-subject variability, the effects of normal aging on RG and YB thresholds, and the spread in RG color thresholds in deutan and protan subjects. A statistical model was developed to optimize the parameters of the CVS test and to predict the limits of what can be achieved in color assessment. The efficiency and repeatability of the CVS test were then assessed in 84 subjects. The results match model predictions and reveal close to 100% test efficiency. The test takes between

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Assessment of novel binocular colour, motion and contrast tests in glaucoma

et al. 2013

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This is the unspecified version of the paper.This version of the publication may differ from the final published version. The effects of glaucoma on binocular visual sensitivity for detection of different stimulus attributes were investigated at the fovea and in four paracentral retinal regions. The study employed a number of visual stimuli designed to isolate the processing of different stimulus attributes. We measured absolute contrast detection thresholds and functional contrast sensitivity using Landolt ring stimuli. This psychophysical Landolt C based contrast test of detection and gap discrimination allowed us to test parafoveally at 6° from fixation as well as foveally employing interleaved testing locations. First-order motion perception was examined using moving stimuli embedded in static luminance contrast noise. Red/green (RG) and yellow/blue (YB) colour thresholds were measured with the Colour Assessment and Diagnosis (CAD) test, which utilises random dynamic luminance contrast noise (±45%) to ensure that only colour and not luminance signals are available for target detection. Subjects were normal controls (n = 65) and glaucoma patients with binocular visual field defects (n = 15), classified based on their Humphrey Field Analyzer mean deviation (MD) scores. The impairment of visual function varied depending on the stimulus attribute and location tested. There was also a progression of loss for all tests as the degree of glaucoma increased. For subjects with mild glaucoma (MD -0.01dB to -6.00dB) significantly more data points fell outside the normal age-representative range for RG colour thresholds than for any other visual test, followed by Motion thresholds. This was particularly the case for the parafoveal data compared to the foveal data. The findings suggest that a multifaceted measure of binocular visual performance, incorporating RG colour and motion testing at multiple locations, may provide a better index for comparison with QOL measures in glaucoma. Permanent repository link

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Effects of hypoxia on color vision with emphasis on the mesopic range

Cited by 15 publications

References 49 publications

Changes in color vision with decreasing light level: separating the effects of normal aging from disease

Changes in color vision with decreasing light level: separating the effects of normal aging from disease

Color vision assessment‐3. An efficient, two‐step, color assessment protocol

Assessment of novel binocular colour, motion and contrast tests in glaucoma

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