Color Blindness

By Gretchyn Bailey; reviewed by Vance Thompson, MD

Color blindness is not a form of blindness at all, but a deficiency in the way you see color. With this vision problem, you have difficulty distinguishing certain colors, such as blue and yellow or red and green.

Red-green color deficiency is the most common form of color blindness; a less common form is blue-yellow color deficiency.

Color Blindness Symptoms and Signs

Do you have a hard time telling if colors are blue and yellow, or red and green? This is the primary sign of this vision problem. Contrary to popular belief, it is rare that a color-blind person would see only in neutral colors or shades of gray.

What Causes Color Blindness?

Color blindness occurs when certain cells in the retina that normally respond to color do not respond as they should.

The problem affects more men than it does women, and usually, people with a color deficiency are born with it.

Color blindness is caused by a common X-linked recessive gene. This means, if you're color-blind, your mother must either be color-blind or have normal vision but carry the color-deficient gene.

Aging or disease can also damage retinal cells and in extreme cases can lead to almost total color blindness.

Color-blind fathers pass the gene to their daughters only, who will have normal color vision unless their mother also carries the color-deficient gene.

Eye doctors use Ishihara plates to determine the severity and type of color deficiency. With normal color perception you can see the numeral among the dots. But with red-green deficiency you would have trouble seeing the red among the green.

Color Blindness Treatment

Color blindness cannot be cured. However, if you have difficulty distinguishing colors, or you've observed this difficulty in your child, see your eyecare practitioner.

Diagnosing color-vision deficiency early may prevent learning problems during the school years, since many learning materials rely heavily on color perception. If your child has a color deficiency, be sure to speak with his or her teachers about it, so they can plan their lessons accordingly.

Some people use special lenses for color blindness, which are filters available in either contact lens or eyeglass lens form. They are available from a limited number of eyecare practitioners in the United States and other countries.

You can also learn ways to work around your inability to pick out certain colors. For example, you might organize and label your clothing to avoid color clashes. (Ask friends or family members to help!) And you might remember the order of things rather than their color (i.e., the red light is at the top of a traffic light).

[Page updated June 2007]