This defect may range from a slight inability to recognize shades of a color to complete loss of color vision which is a rare condition called monochromasia in which everything is seen in shades of gray. The more common types of color deficiency involve the inability to see red, green or blue. Color deficiency is usually caused by a genetic defect inherited from the mother. However, there are other types of color deficiency that are caused by aging , certain medications, and certain eye diseases, such as diseases of the retina or optic nerve. If you or your child are having difficulty distinguishing between colors, you should see an eye doctor for an evaluation.
Most children can recognize and name the colors red, green and blue by the age of four.
There is no cure for color deficiency that has been present since birth. Wearing colored contact lenses is only minimally effective in correcting defective color vision and may cause other eye problems like reducing the sharpness of vision and distorting depth perception. There are techniques that can be learned to help you live with color blindness, such as learning to recognize colors by association. For example, learn that the top light of a traffic signal is red and means stop, while the bottom light is green and means go. In addition, family members can help.