Color blindness (color vision deficiency) is a condition in which certain colors cannot be distinguished, and is most commonly due to an inherited condition. Red/Green color blindness is by far the most common form, about 99%, and causes problems in distinguishing reds and greens. Another color deficiency Blue/Yellow also exists, but is rare and there is no commonly available test for it.
Depending on just which figures you believe, color blindness seems to occur in about 8% – 12% of males of European origin and about one-half of 1% of females. I did not find any figures for frequency in other races. Total color blindness (seeing in only shades of gray) is extremely rare.
There is no treatment for color blindness, nor is it usually the cause of any significant disability. However, it can be very frustrating for individuals affected by it. Those who are not color blind seem to have the misconception that color blindness means that a color blind person sees only in black and white or shades of gray. While this sort of condition is possible, it is extremely rare. Being color blind does keep one from performing certain jobs and makes others difficult.
Some of the information in these pages was taken from:
An article by: Diana H. Heath, M.D., a member of the Morton Plant medical staff, specializing in ophthalmology. (formerly at http://www.zipmall.com/mpm-art-colorbl.htm)
A webpage written by Terrace L. Waggoner, O.D., Staff Naval Hospital, Pensacola (formerly at http://members.aol.com/nocolorvsn/color2.htm)