Correspondence between visual acuity, refractive error, and the speed of visual perception.

CORRECTION of refraction is usually expected to improve not only visual acuity but also the speed of visual perception, at least to the physiologic maximum for the particular individual. A previous study (Eames, 1949) has shown a generally increasing frequency of cases exhibiting increase in visual perception speed at successively higher dioptric levels, after correction of both hypermetropic and myopic errors. It also showed a decrease in the speed of visual perception after correction in an appreciable percentage of cases, particularly among the myopic group. The present study is intended as a step toward further understanding of the relationship of visual acuity, refractive error, and the speed of visual perception. The speed of visual perception was measured tachistoscopically with projected pictures of common objects shown at the reading distance, before and after correction of refraction in school children between the ages of 6 and 17. The results were correlated with visual acuity and with the amount of refractive error by means of the Spearman rank-difference-squared method (see Table).