Color vision and occupational chemical exposures. II. Visual functions in non-exposed subjects.

This paper presents data on visual functions (visual acuity, contrast sensitivity, and several tests of color vision), in a group of 199 non-exposed healthy subjects with an even distribution over the age range 18-65 years, and sex. Although subjects with obvious congenital color vision deficiencies were removed from the analyses (four males), females were superior to males on several of the color vision tests applied. Age influenced visual acuity and contrast sensitivity, while color discrimination was less affected. Correlations between functions of the right and the left eye in the individual subjects were rather low, ranging from 0.40 to 0.73. Correlations between visual acuity and contrast sensitivity on the one hand and color discrimination ability on the other hand were still lower (r < 0.20). These low correlations between functions in the two eyes support the need for testing each eye separately.