Eye Facts Color Blindness Color blindness is used in colloquial terms to refer to the difficulty in telling colors apart but a more correct term would be color vision defect.
Color blindness is a misnomer because only a small percentage of people are unable to see any color.
Persons with color vision defects may be at a disadvantage in school or at work. In fact, lack of normal color vision may limit career opportunities. For example, normal color vision is vital in such jobs as color printing and color photography. Abnormal color vision can even be dangerous in certain situations, such as in rail and water navigation. For this reason, persons with color vision defects are excluded by law from certain occupations.