title: Color vision deficiencies in youths 12-17 years of age, United States.
abstract: Presented in this report are data on the prevalence of color vision deficiencies in American youths 12-17 years of age as estimated from the Health Examination Survey of 1966-70. The data are stratified by age, sex, race, geographic region, size of place of residence, and annual family income. Comparisons are also made with the findings from the 1963-65 Health Examination Survey among children 6-11 years of age. Color vision deficiency, commonly called color blindness, manifests itself in everyday life in the confusion of, or blindness to, one or more primary colors, and its origins may be congenital or acquired. Congenital defects occur in two chief forms, total and partial. The former is very rare and is generally associated with nystagmus and a central scotoma. All colors appear as grays of differing brightness. The partial form is the most common type of color vision defect and is primarily an inherited condition transmitted through the mother, who is usually unaffected. It is probably due to the absence of one of the photopigments normally found in the foveal cones. In most cases reds and greens are confused. Acquired defects of color vision may often develop in, the course of ocular, mainly retinal, disease. Red-green defects are frequently characteristic of lesions of the optic nerve and optic pathways, while blue-yellow defects are more likely to result from lesions of the outer layers of the retina.
authors.forename: D
authors.initials: D
authors.lastname: Slaby
authors.forename: J
authors.initials: J
authors.lastname: Roberts