All ETDs from UAB

Advisory Committee Chair

Michael Loop

Advisory Committee Members

Lawrence Sincich

Timothy Gawne

Lei Liu

Patti Fuhr

Document Type

Dissertation

Date of Award

2021

Degree Name by School

Doctor of Philosophy (PhD) School of Optometry

Abstract

COLOR VISION TESTING WITH READILY AVAILABLE MATERIALS ANGEL PEREZ VISION SCIENCE ABSTRACT The perception of color is a process by which the brain discriminates different light wavelengths stimulating the cone photoreceptors in the retina of the eye. In humans each cone contains a photopigment making it most sensitive to either short (red), medium (green), or long (blue) wavelengths of light. However, when one of the cone pigments is defective or missing, color discrimination is reduced, resulting in color vision deficiency due to a deficient sex-linked chromosome in most cases. Color vision deficiency has the potential to impede many everyday activities, interfere with the learning processes for children beginning at a very early age, and prohibit participation in numerous careers and occupations for which color recognition is critical. This study examined four economized tests we developed as possible screening tools for color vision deficiency (CVD) that can be used in educational environments where children could be assessed. This study explored the ability to develop a valid and reliable color vision test using materials that are readily available and easily accessible and were compared to the widely used Hardy, Rand and Rittler Pseudoisochromatic Plates. Forty- nine subjects (35 normal and 14 color vision deficient) performed the HRR, crayon, color board, paint chips, and a psychophysical measure, the red test projected on a gray background. The HRR had a 37% error rate with plate 7 for normals and 6% of normals and 10% of the CVDs made errors on the crayon test and does not discriminate well between normals and mild CVDs. Next, 17% (35 subjects) of the normal subjects made errors on the color board test and 57% (14 subjects) of the CVDs had 100% accuracy. With the paint chips test, normals identified all colors with 100% accuracy while only 36% (14 subjects) of the CVDs made errors. The normals performed well with the red test even with the smallest increment 0.75, while the CVDs performance was worse on average and scores for the smallest increment indicated that this population guessed for due to the inability to detect this increment. Our findings indicate that both the color board and crayon tests were not reliable because of the desaturation of color in both. The paint color test results were slightly better; however, they issue with these tests are that they would need to be measured using a spectrometer to match the confusion line on the CIE Chromaticity diagram. The red test was determined to be consistent with the HRR and can detect most CVDs, and those with the most severe CVD in comparison to the normals do not appear to be the source for the difference in CVD variation levels. Keywords: Color Vision Deficiency, Hardy-Rand Rittler, Protan, Deutan

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