The prevalence of color vision deficiencies among youths 12 to 17 years of age in the United States was evaluated during a 1966-1970 survey of 6,768 youths selected as representative of noninstitutionalized adolescents with respect to age, sex, race, geographic region, income, population size of place of residence, and rate of population change in the place of residence from 1950 to 1960. Findings indicated that approximately 4% of adolescents have color vision deficiencies with boys about 12 times more likely to have this defect than girls. No significant differences were found in the prevalence rates for white and Negro boys except in the South. Red-green color vision deficiencies were substantially more prevalent than blue-yellow defects, which were found only in conjunction with the red-green defect. Age was not related to the prevalence of color vision deficiencies. No statistically significant regional differences in the prevalence of red-green deficiencies were found, although a significant racial difference was observed in the South (three times as many white as Negro boys had red-green deficiencies). Differences in the prevalence rates across income levels were negligible. (Approximately half the document consists of detailed tables of the survey's findings.) (Author/DB)