Caucasian boys show highest prevalence of colour blindness among preschoolers

A  study of colour blindness in a multi-ethnic group of preschoolers has found that caucasian male children have the highest prevalence among four major ethnicities, with one in 20 testing color blind. Researchers also found that colour blindness, or colour vision deficiency, in boys is lowest in African-Americans, and confirmed that girls have a much lower prevalence of colour blindness than boys. The study is published online in  Ophthalmology, the journal of the American Academy of Ophthalmology.

Researchers from the Multi-Ethnic Pediatric Eye Disease Study Group tested 4,005 California preschool children age 3 to 6 in Los Angeles and Riverside counties for color blindness. They found the following prevalence by ethnicity for boys:

5.6 percent of Caucasian boys
3.1 percent of Asian boys
2.6 percent for Hispanic boys
1.4 percent of African-American boys

The prevalence of color blindness in girls measured 0 percent to 0.5 percent for all ethnicities, confirming findings in prior studies. However, the numbers were so low overall for girls that researchers say they cannot statistically compare rates between females among the four ethnicities studied.

While the researchers found that children at the youngest ages could not accurately complete testing, they say the findings suggest that successful color vision screening can begin at age 4. Many times children with color blindness will perform poorly on tests or assignments that employ color coded materials, leading color blind children to be inappropriately classified by ability at school, said the study’s principal investigator Rohit Varma, M.D., chairman of the Department of Ophthalmology at the University of Southern California (USC) Keck School of Medicine and director of the USC Eye Institute.