Color Blindness

Many people refer to problems with one s ability to see color as color blindness, however, unless a person can t see any color at all, color vision problems should be called by another term. Common terms are abnormal color vision, color deficiency and color vision confusion. Females maybe be effected by color blindness, but usually they are just carriers. Males are more often affected. About 8% of males and 0.5% of females are effected by color blindness.

Although color blindness may be a result of another eye disorder, the majority of color blind cases are hereditary and present at birth.

The retina, is a complex nerve system which converts light energy into electrical energy that is then transmitted to the brain. This conversion is accomplished by two types of receptor cells in the retina called rods and cones do to their shape. The cones are responsible for converting the color. Each cone contains visual pigments that are sensitive to one of three wavelengths of light: red, green and blue. Normally, all colors of the spectrum are able to be matched by mixtures of only three color sensitivities. Therefore, the huge variety of colors we see are a response to different compositions of wavelengths

of light. The rods are responsible for encoding white and black.

Color blindness results when one or more of the cone cells fail to function properly. One of the visual pigments may be functioning abnormally, or be absent altogether.

There are several different types of color blindness, however, complete color blindness, or achromatopsia, is probably the simplest to understand. This is the rarest form of color blindness. This is when no colors can be seen at all. The color receptors are almost completely gone in this form, however, the white and black receptors remain intact. However, this condition is often misdiagnosed without proper testing.

There are three basic types of color blindness: deuteranopia, protanopia and tritanopia. Deuteranopia is a condition in which people have trouble dealing with green. These people are one of the largest groups of color blind people. Very often, these people also have a problem with red. These people can often distinguish red or green when with other colors, but when it is by itself, it is very difficult. Many people will just see it as white.

Protanopia are those seem to need an abnormal amount of red or have no sense of red color vision. Often, people will see bold red as black or nonexistent. Some people may see red-orange as brown and yellow-green as brown. In other words, neither red or green can often be distinguished for sure.

Tritanopia are those who have trouble distinguishing blue and yellow. This disorder is much less common than the red-green colorblindness, and is usually acquired, not received through heredity. These people may see both blue and yellow as white. They may even see mint green or pink as an equal to light blue.

Red color blindness is the most common. This is when the red color receptors are nonexistent. These people either don t see red or they see it as black. When the red color receptors are just malfunctioning, they will see red as dark brown or orange. These people often have trouble distinguishing between orange, yellow and green. They might see orange as yellow, because orange is yellow with some red in it.

Green color blindness is when the green receptors are malfunctioning or missing. Green is the color most sensitive to rods. These people may see green is yellow, blue, gray, white or even orange. For example a field at a baseball game would be orange. This person might also see blonde hair as white or green.

Some medicines for other afflictions and toxins can also cause temporary color blindness.

Red-green color blindness is basically a combination of red and green color blindness. This results from having defective red and green color receptors.

Color blindness is normally diagnosed through clinical testing. Most color blind people compensate well for there affliction and may even discover instances in which the notice details that escape a normal person s vision.

Works Cited

Coping With Blindness, Odeda Rosenthal and Robert H. Phillips, PhD, Avery Publishing

Group, Garden City Park, New York: 1997

Color Blindness, Access Health, Inc., 1996

Morton Plant Mease Articles: Color Blindness, Diana H. Health, M.D., Morton Plant

Color Blindness, Unknown webpage.

Color Blindness, Robert A. Berthold

The Physiological Factors That Effect Color Perception, unknown website.