Color Blindness
Overview
Color blindness is a condition in which certain colors cannot be distinguished and is most commonly due to an inherited condition. The human eye has three types of cone cells which are sensitive mainly to red, green and blue, respectively. Colorblindness is the situation where one of the types of these cones does not function correctly.
Prevalence
Colorblindness is among the most prevalent visual impairments and is predominant in males. It occurs in about 8% of Caucasian, 5% of Asian, and 4% of African males. However, only about 0.5% of females. This is due to the fact that the genetic trait that causes colorblindness is generally transmitted by sex chromosome.
Types
Red-Green Colorblindness
A normal person can see three colors, which is called trichromancy, but if one of the types of cone cells is not functioning properly, the person will lose vision of one of the three colors and this is called dichromancy. There are several types of colorblindness, with the most common (over 99%) being Red-Green colorblindness. There are two types of red-green colorblindness.
Deuteranopia: Deuteranopes have partially or completely lost the function of their green cones. If they have only partially lost their ability to see green, they will see the color green as weaker than an equal frequency of red or blue. This partial vision loss is called anomalous trichromancy. If they have totally lost their ability to see the color red, this is called dichromancy.
Protanopia: Protanopes have partially or completely lost their ability to see the color red.
Rarer Forms
There are two much rarer forms of colorblindness.
Tritanopia: Tritanopes have lost the ability to see blue. However, they represent only about .001% of the population.
Monochromancy: If two types of cones fail in the same person, that person will lose their ability to distinguish all color and see everything as only differences in brightness. This is the least common form of colorblindness.
Cures
There is no treatment for colorblindness and it cannot be overcome through eye exercises.