Document Type



Master of Science


Physiological Optics

Date of Defense


Graduate Advisor

Carol K. Peck, Ph.D.


Carl Bassi Ph.D.

Ralph Garzia O.D.


Dyslexia is surrounded by much uncertainty over its cause and its treatment. While many view dyslexia as a purely phonological deficit, some have proposed a visual deficit as a cause in at least some poor readers. Several treatments have been have used to increase visual processing as a means of overcoming such visual deficits. Using a blue colored filter to increase magnocellular processing has seen the most successful outcomes. Tests of coherent motion under different background color conditions were completed on a group of 16 highly educated subjects who also underwent several tests of reading ability. There were no significant differences between the motion thresholds taken under the different color conditions and the motion thresholds did not correlate with any reading measure. However the difference between the white baseline coherent motion threshold and the low contrast gray threshold significantly correlated with several of the reading measures, indicating that poorer readers gained the most increase in motion sensitivity when using a low contrast gray background. This suggests that benefits seen from using colored filters may be due to the reduction in contrast rather than the effect of color. More research needs to be done on the effect of color on both the magnocellular pathway and on reading performance.

OCLC Number