(HealthDayNews) -- Have you asked your child to hand you a green toy, but he recognizes it as brown?
If so, he may have color blindness, an incurable condition of the optic nerve or retina that makes it difficult or impossible to distinguish between colors.
Inherited color blindness is most common, affects both eyes, and does not worsen over time. Most often, this variety causes difficulty distinguishing between reds and greens. The condition is almost always passed from mother to son.
A person also can become color blind after a disease that damages the eye. People who acquire color blindness this way usually have trouble distinguishing blues and greens.
