Q: I am worried that my four-year-old son may be colour-blind. There’s a family history of it and he seems to guess at colours. Is it possible to diagnose it at this early age?
A: Colour-blindness is an inability of certain parts of the retina, called cones, to differentiate pigments — either red from green or blue from yellow, or both. It is more common in males because it is genetic and involves genes found on the X chromosome.
The degree of colour-blindness may vary from very mild to complete. It can be determined using special cards when the child is old enough to co-operate with the test. Fortunately, the disability is usually mild, but can interfere with some career choices, for example, airline pilot. There have been articles about lenses that can help enhance the shading and help differentiate colours. For children, the issue is that some learning materials are colour coded — make sure your son’s teacher is informed about the issue.