Color Blindness Factsheet (for Schools)
Medically reviewed by: Mary L. Gavin, MD
What Teachers Should Know
Color blindness is caused by problems in the color-detecting nerve cells located in the back of the eye, called cones. As a result, some people have trouble telling the difference between red and green (the most common kind of color blindness), and between blue and yellow. Achromatopsia is a rare a form of color blindness in which people can't see any colors — they only see shades of gray.