Definition

Color blindness usually affects a person’s ability to distinguish between shades of red and green or between shades of blue and yellow. Complete color blindness, which is very rare, causes a person to see most objects in shades of gray.

Color blindness occurs when light-sensing chemicals in the eye do not work properly.

If you suspect you have this condition, contact your doctor. Although most color blindness cannot be cured or treated, you can learn simple ways to manage your difficulty seeing color differences. Some cases of color blindness may indicate another illness that will require treatment.

Causes

Most color blindness is inherited. Less frequently, color blindness is caused by a disease affecting the optic nerve or retina. This is referred to as “acquired color blindness.”

Anatomy of the Eye

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Risk Factors

Heredity is the primary factor that controls your chance of having color blindness. If your mother, father, or grandparents were color blind, you may have the gene(s) that cause color blindness.

The following risk factors increase your chance of developing acquired color blindness:

• Males are more likely than females to have color blindness.
• Having certain diseases may increases your risk for developing color blindness.
• Certain medications, including some that are prescribed for heart problems, high blood pressure]]> , or nervous disorders, may increase your risk for developing color blindness or deficiency.

Symptoms

If you cannot distinguish between some colors—particularly red and green or blue and yellow—see your doctor to determine if it is color blindness or another health condition.

Diagnosis

Your doctor will ask about your symptoms and medical history, and perform an eye exam and a simple vision test. or will refer you to an ophthalmologist (eye specialist) for testing. You may want to consider going to an eye specialist directly, instead of your medical doctor, since the eye specialist may be better suited to make a diagnosis.

Tests may include the following:

• Ishihara plates test—you will be asked to identify numbers or objects made of colored dots, surrounded by other dots of other colors
• An arrangement test—you will be asked to group or arrange chips according to their color

Treatment

There is no cure for inherited color blindness; however, most people with color blindness learn to distinguish between colors accurately and easily.

Talk with your doctor about coping skills. Additionally, depending on the level of color blindness, some doctors recommend using color-corrective glasses or contact lenses.

In some cases of acquired color blindness or deficiency, such as those caused by cataracts]]> or another disease, treatment of the cataract or other medical problem may correct the color blindness, as well.

Prevention

To help reduce your chances of getting acquired color blindness, discuss your use of prescribed medicines with your doctor.