Color blindness is the inability to perceive colors in a normal fashion. There are different types of colorblindness. The most common forms of the condition are inherited in a sex-linked (X-linked) recessive manner, meaning that females are carriers and males are affected. The most common form of colorblindness is red-green, and symptoms can vary widely among those affected. The second most common form of colorblindness is blue-yellow. The true inability to perceive any color at all is a very rare form of colorblindness.

Symptoms associated with colorblindness include the inability to distinguish shades of green, red, blue, or yellow, or trouble seeing the brightness of colors in the usual way. The signs and symptoms of red-green and blue-yellow colorblindness may be very mild. It is possible that affected people are unaware they are colorblind unless specifically tested.

Causes of color blindness

Color blindness is usually a genetic condition. Age, cataracts, optic nerve damage, chemical or physical damage to the eye, or brain damage to the part of the brain that processes color information also may cause color blindness.