Finally a major study of color blindness in kids

Color blindness overwhelming affects non-Hispanic white boys, according to what is perhaps the first population-based study of color vision deficiency (CVD) in preschool children.

The study also found that kids can be reliably tested for color blindness by the time they are aged 4 years.

The Multi-Ethnic Pediatric Eye Disease Study, supported by the National Eye Institute, included approximately 4000 preschool children, aged 30 to 72 months, who were from Southern California and able to complete color vision testing. The age of the population helped to ensure study of congenital versus acquired CVD. Of the total testable study population, 1265 were black: 812 were Asian; 1280 were Hispanic; and 820 were non-Hispanic white.

The researchers found that of the testable children, 98% had normal color vision. Only 1.6% (63 children) did not. Of the 63, 59 were boys-corresponding to a rate of 3% of all the testable boys-and 4 were girls (0.02% of testable girls).

When the investigators looked at ethnicity, they found that prevalence was highest among non-Hispanic white children (5.6%), followed by Asian children (3.1%), Hispanic children (2.6%), and black children (1.4%).

They also found that color vision testing is of questionable reliability in children aged younger than 37 months. Only 17% of children in that age group could be reliably tested. Testability increased to 57% in children aged 37 to 48 months; to 89% in children aged 49 to 60 months; and to 98% in children aged 61 to 72 months.

According to findings from the last National Health Examination Survey that evaluated data on CVD in children in the United States, color blindness affects about 3.8% of children aged between 6 and 11 years, with boys about 13 times more likely to be affected than girls.

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