Colorblindness Disorder

Color blindness disorders, also called color vision disorders, affect about one in every 33,000 people in the United States. Color blindness disorders affect a person's ability to ascertain specific colors, and in some instances all colors. Color blindness disorders occur in individuals who have malfunctions of the retina, the inner eye lining.

Types

• There are three standard types of color blindness. Total color blindness, also called achromatopsia, is the rarest form. Totally color blind people can see only shades of gray, black and white and usually experience overwhelming light sensitivity. Red/green color blindness is the most common color blindness disorder. People with red/green color blindness can distinguish red or green colors only when they are contrasted with other colors. Blue color blindness sufferers cannot see the colors yellow or blue.

Causes

• Inherited genetic imperfections are the leading causes of color blindness disorders. However, color blindness disorders can be obtained through illnesses such as chronic alcoholism, liver disease, diabetes, glaucoma, multiple sclerosis and the eye disease retinitis pigmentosa. Other causes of colorblindness disorder are eye damage from strokes or accidents, reaching older age, toxins such as fertilizers, carbon monoxide and lead-ridden chemicals. High-blood-pressure medications, antibiotics, psychological- and nervous-disorder medications and barbiturates may also cause color blindness disorder.

The Role of Heredity in Color Blindness Disorder

• Most people who are affected by color blindness disorder are men, especially Caucasian men. However, women are usually the defective gene carriers and ultimately are the ones who pass the disorder on to their male offspring. The color blind male will then pass on the color blindness disorder carrier trait to his daughters, whose own sons will have a 50 percent chance of inheriting a color blindness disorder. However, the color blind male's sons will not have color blindness disorder. The color blind male's sisters will receive the carrier gene and the sister's sons will also have a 50 percent chance of being born color blind.

Diagnosis

• One of the color blindness disorder diagnostic tests is the Titmus II Vision Center Perception Test. This test measures red/green color blindness and involves the subject looking through a viewing device at an arrangement of characters against a black backdrop outlined in yellow to determine whether he can distinguish red and green colors. Two other common color blindness disorder tests are the American Optical/Hardy, Rand and Ritter Pseudoisochromatic Test and the Ishihara test. In both of these, subjects attempt to decipher color blots and figures arranged on plates.

Considerations

• Inherited color blindness disorder is not a treatable condition. People afflicted with color blindness disorders rely on their learned skills, such as traffic stop sign configurations, to cope with their conditions. Color blindness disorders that were acquired through diseases, chemical polluters and medications may become worse or better over time. Most people with color blindness disorders experience adequate vision and live normal lives, although some professions--such as firefighting, certain medical professions and some transportation fields--prohibit people with color blindness disorders from working within their industries because of safety concerns.