Most people refer to problems with color vision as color blindness.
However, unless a person is totally unable to see any color, problems with color vision should be called color deficiency, which means abnormal color vision. About eight percent of males and less than one percent of females are born with a color deficiency. 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.