Colour blindness means that you have trouble seeing red, green, or blue or a mix of these colours. It’s rare that a person sees no colour at all.
Colour blindness is also called a colour vision problem.
A colour vision problem can change your life. It may make it harder to learn and read, and you may not be able to have certain careers. But children and adults with colour vision problems can learn to make up for their problems seeing colour.
Most colour vision problems are inherited (genetic) and are present at birth.
People usually have three types of cone cells in the eye. Each type senses either red, green, or blue light. You see colour when your cone cells sense different amounts of these three basic colours. The highest concentration of cone cells are found in the macula, which is the central part of the retina.
See a picture of the eye that shows the retina and the macula.
Inherited colour blindness happens when you don't have one of these types of cone cells or they don't work right. You may not see one of these three basic colours, or you may see a different shade of that colour or a different colour. This type of colour vision problem doesn't change over time.
A colour vision problem isn't always inherited. In some cases, a person can have an acquired colour vision problem. This can be caused by:
The symptoms of colour vision problems vary:
Tests measure how well you recognize different colours.
Because a colour vision problem can have a big impact on a person's life, it is important to detect the problem as early as possible. In children, colour vision problems can affect learning abilities and reading development. And colour vision problems may limit career choices that require you to tell colours apart. The Canadian Paediatric Society recommends eye examinations at all newborn and well-child visits. Children with a family history of inherited eye problems should see an ophthalmologist by the age of three months.1
Inherited colour vision problems cannot be treated or corrected.
For the most common type of colour blindness—red-green colour deficiency—no treatment is needed, because you function normally. You may not be aware that you do not see colours the way they are seen by others.
Some acquired colour vision problems can be treated, depending on the cause. For example, if a cataract is causing a problem with colour vision, surgery to remove the cataract may restore normal colour vision.
You can find ways to help make up for a colour vision problem, such as:
Colour vision problems may make it harder for children to learn and read, which can lead to poor schoolwork and low self-esteem.
You can help your child these ways.
Learning about colour blindness:
|American Optometric Association (AOA)|
|243 North Lindbergh Boulevard|
|St. Louis, MO 63141-7881|
The American Optometric Association (AOA), which is a national organization of optometrists, can provide information on eye health and eye problems.
|Canadian National Institute for the Blind (CNIB)|
|1929 Bayview Avenue|
|Toronto, ON M4G 3E8|
The Canadian National Institute for the Blind (CNIB) is a voluntary agency dedicated to helping improve the lives of the blind and visually impaired, preventing blindness, and promoting sight enhancement services. The organization offers a variety of publications and educational resources about vision loss and impairment.
|Canadian Ophthalmological Society|
|610-1525 Carling Avenue|
|Ottawa, ON K1Z 8R9|
The Canadian Ophthalmological Society is an association of eye doctors dedicated to helping the public take good care of their eyes and vision. This group provides educational information on eye conditions and diseases and eye safety.
|P.O. Box 429098|
|San Francisco, CA 94142-9098|
EyeCare America is a public service program of the Foundation of the American Academy of Ophthalmology. This site aims to raise awareness about eye diseases and eye care. It has information about eye conditions, treatments, and general eye health. You can check to see if you qualify for a free eye examination.
|Prevent Blindness America|
|211 West Wacker Drive|
|Chicago, IL 60606|
Prevent Blindness America assists the visually impaired and provides consumer information on vision problems and vision aids. Its website has information about eye health and safety for children and adults. Many states have local affiliates.
- Community Paediatrics Committee, Canadian Paediatric Society (2009). Vision screening in infants, children and youth. Paediatrics and Child Health, 14(4): 246–248. Available online: http://www.cps.ca/english/statements/cp/cp09-02.htm
- American Academy of Pediatrics, et al. (2003, reaffirmed 2007). Policy statement: Eye examination in infants, children, and young adults by pediatricians. Pediatrics, 111(4): 902–907.
Other Works Consulted
- Fletcher EC, et al. (2011). Retina and retinal disorders. In P Riordan-Eva, JP Whitcher, eds., Vaughan and Asbury's General Ophthalmology, 18th ed., pp. 190–221. New York: McGraw-Hill.
- Sieving PA, Caruso RC (2009). Retinitis pigmentosa and related disorders. In M Yanoff, JS Duker, eds., Ophthalmology, 3rd ed., pp. 550–559. Edinburgh: Mosby Elsevier.
|Primary Medical Reviewer||Adam Husney, MD - Family Medicine|
|Primary Medical Reviewer||Anne C. Poinier, MD - Internal Medicine|
|Specialist Medical Reviewer||Christopher J. Rudnisky, MD, MPH, FRCSC - Ophthalmology|
|Last Revised||October 17, 2011|
Last Revised: October 17, 2011
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