Basic and Applied Studies of Human Visual Function: Implications for Visually Demanding Occupations
Date of Degree
Doctor of Philosophy (PhD)
Color vision is a complex process providing important information about objects within our environment. Color vision deficiency either congenital or acquired can impact real world performance. Current working environments either require normal color vision or utilize color as a tool to highlight critical information. The use of color in the workplace provides several advantages. Hence, color vision screening is required for entry into professions and occupational certifications. Acquired color vision deficiency may also impact job performance requiring clinical screening. The present dissertation focused on the considerations outlined by the Commission on Behavior and Social Sciences when choosing a clinical test for occupational purposes. In order to address these considerations, I conducted a series of four studies.
The first study compared and contrasted three different computerized color vision tests for contrast sensitivity and analyzed how the minimum cutoff score differed between the tests. The results indicated that while log CS values were similar, there were enough differences between the values that caution should be applied when using the tests interchangeably for occupational screening. The second study assessed the Color Vision Field Test and found that it has excellent sensitivity and specificity for occupational screening when appropriate protocols are followed. The third study determined if the Cone Contrast Test could predict performance on the FM-100 Hue thereby providing a potential alternative test to the FM-100. Results indicated the CCT may be an effective substitute for the FM-100 to provide certification of jewelry appraisers, but the small sample size warrants additional comparative validation to support sole utilization of the CCT. This study also revealed exceptional hue discrimination in jewelry appraisers, a possible effect of perceptual learning. The last study expanded previous research on cell phone distraction to auditory distraction with a navigational system. Delayed response time was found which poses a threat to safety.
Lovell, Julie, "Basic and Applied Studies of Human Visual Function: Implications for Visually Demanding Occupations" (2021). Theses & Dissertations. 391.