Achromatopsia - Color Blindness
- Overview, Causes, & Risk Factors
- Symptoms & Signs
- Diagnosis & Tests
- Prevention & Expectations
- Treatment & Monitoring
Overview, Causes, & Risk Factors
Color blindness ranges from the inability to distinguish similar shades of a color, to the complete inability to see color. Dyschromatopsia refers to the ability to see some colors, but not others. Achromatopsia, which is rare, refers to the inability to see colors at all.
What is going on in the body?
Most of the time, color blindness is a genetic defect that is present when the individual is born. Less commonly, color blindness occurs as part of aging or is caused by a medication or disease.
What are the causes and risks of the condition?
Color blindness is usually caused by an inherited trait. Dyschromatopsia, or the inability to see some colors, occurs in about 8% of men and less than 1% of women. Color blindness may also be caused by some medications or by normal aging of the lens of the eye. Disorders of the retina of the eye, or of the optic nerve from the eye to the brain, may also interfere with color perception.
Symptoms & Signs
What are the signs and symptoms of the condition?
An individual with achromatopsia cannot tell the difference between colors. Some people with achromatopsia can only see shades of gray. A person with this condition usually has poor distance vision, light sensitivity, and rapid eye movement.
Dyschromatopsia is the more common form of color blindness. Individuals with this condition usually have excellent vision. The person usually cannot tell the difference between shades of red and green. In rare cases, the person cannot tell the difference between shades of blue and yellow.
Diagnosis & Tests
How is the condition diagnosed?
Color blindness is usually self-diagnosed. Achromatopsia may not be uncovered until a child is 3 to 5 years old. To confirm the self-diagnosis, the healthcare provider usually performs a color test. Common tests include the HRR pseudoisochromatic plates or the Ishihara plates. The diagnosis of achromatopsia is sometimes determined by performing an electric eye test. This test is called an electroretinograph.
Prevention & Expectations
What can be done to prevent the condition?
In general, there is no way to prevent color blindness. Regular eye exams and prompt treatment of eye disorders may help prevent some cases of color blindness.
What are the long-term effects of the condition?
Color blindness is a lifelong condition. It's important to determine color blindness as early as possible. Individuals can be taught to cope with employment, hobbies, and games that require more exact color vision.
What are the risks to others?
Color blindness is not contagious, and poses no risk to others. It is an inherited trait in most cases. Children of a person with color blindness are more likely to develop the condition. Genetic counseling may be helpful to families with a history of color blindness.
Treatment & Monitoring
What are the treatments for the condition?
There are no known medical, surgical, or nutritional treatments available for color blindness. Individuals with dyschromatopsia can see the difference between bright red and green as in traffic lights. However, this could be risky if the person drives or operates heavy machinery. Proper precautions should be taken.
Adaptive equipment and techniques can be used to provide cues to the person with color blindness. Wearing dark lens glasses can sometimes help individuals with achromatopsia.
What are the side effects of the treatments?
There are no side effects to the adaptive equipment and techniques used to help a person with color blindness.
What happens after treatment for the condition?
Color blindness is a lifelong condition.
How is the condition monitored?
Color blindness is monitored through regular eye exams and visits to the healthcare provider. Any new or worsening symptoms should be reported to the healthcare provider.
Author:William Stevens, MD
Editor:Ballenberg, Sally, BS
Reviewer:Eileen McLaughlin, RN, BSN