Colour Blindness; Dominated by Caucasian Boys
Caucasian male children have the highest prevalence among four major ethnicities, with 1 in 20 testing colour blind, according to the first major study of colour blindness in a multi-ethnic group of pre-schoolers. 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 was published online in Ophthalmology, the journal of the American Academy of Ophthalmology.
Despite the name, colour blindness is not a type of blindness, but an inability to see colours accurately. The most common form of colour blindness is genetic and involves a mutation or lack of genes that help the eye see red or green. People with this form of colour blindness cannot tell the difference between the two colours. As this can negatively impact performance in school, early diagnosis of colour deficiency is important so that parents and teachers of colour blind children are aware and able to provide adaptive learning tools and strategies for these children.
Researchers from the Multi-Ethnic Paediatric Eye Disease Study Group tested 4,005 California preschool children age 3 to 6 in Los Angeles and Riverside counties for colour blindness. They found the following prevalence by ethnicity for boys:
- 5.6% of Caucasian boys
- 3.1% of Asian boys
- 2.6% for Hispanic boys
- 1.4% of African-American boys
The prevalence of colour blindness in girls measured 0% to 0.5% 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 colour vision screening can begin at age 4. Many times children with colour blindness will perform poorly on tests or assignments that employ colour coded materials, leading colour 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.
“It’s not that the child is not smart enough or bright enough, it’s that they see the world a little differently,” Dr. Varma said.
According to Dr. Varma, children with colour blindness can benefit from different kinds of lesson plans or homework to demonstrate their understanding of concepts despite their inability to see colours correctly. “That needs to start early on because labelling a child as not smart or bright enough is a huge stigma for the child and causes significant anxiety for the parents and family,” he added.