Testing color blindness
Nearly all people who are “color blind” can see colors but have difficulty distinguishing between certain colors. Not all people who are color blind have trouble with the same colors – most cannot distinguish between reds and greens; some cannot separate blues from yellows; and a very small group have a condition called monochromatism which only allows them to see black and white.
Color blindness of various kinds affects roughly 8% of men – and less than 1% of women.
What Causes Color Blindness?
Color blindness is a genetic condition caused by a difference in how one or more of the light-sensitive cells found in the retina of the eye respond to certain colors. These cells, called cones, sense wavelengths of light, and enable the retina to distinguish between colors. This difference in sensitivity in one or more cones can make a person color blind.
Symptoms of Color Blindness
The symptoms of color blindness are often observed by parents when children are young. In other cases, symptoms are so slight, they may not even be noticed. Common symptoms of color blindness include:
- Difficulty distinguishing between colors
- Inability to see shades or tones of the same color
Treatment for Color Blindness
There is no known cure for color blindness. Contact lenses and glasses are available with filters to help color deficiencies, if needed. Fortunately, the vision of most color-blind people is normal in all other respects and certain adaptation methods are all that is required.