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Color Blindness

(Color Vision Problem; Color Vision Deficiency)


Color blindness is a problem seeing the difference between shades of red and green or shades of blue and yellow. Complete color blindness causes a person to see most objects in shades of gray but this is rare.


Light-sensing receptors in the eye allow us to see color. They do not work properly in those with color blindness. These changes are most often cause by genes. The damaged gene is inherited from the parents.

Less often, color blindness can develop later. It may be due to diseases that affects the retina or nerve of the eye. It can also be caused by certain medicines.

Anatomy of the Eye
Normal Anatomy of the Eye

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Risk Factors

You have a greater risk if your mother, father, or grandparents were color blind.

Factors that may increase your risk of developing color blindness include:

  • Having certain diseases, such as glaucoma and macular degeneration
  • Taking certain medications that can damage the retina and optic nerve, such as hydroxychloroquine


Color blindness will cause problems seeing the difference in some colors. Red and green or blue and yellow are most common colors that are affected.


You will be asked about your symptoms and past health. An eye exam and vision test will be done. You may be referred to an eye specialist for other testing. They may be better able to make a diagnosis.


There is no cure for inherited color blindness. Most people will not need treatment. Over time they learn ways to tell the difference between colors.

Some tools may help those who need more help with everyday tasks. Options include:

  • Color-corrective glasses or contact lenses
  • Mobile device apps that can show differences between colors and some shades of color

Some with acquired color blindness may be able to regain their color vision. Treatment of the medical problem or a change in medicine may correct the color blindness.


There are no known steps to prevent color blindness.


American Academy of Ophthalmology

Howard Hughes Medical Institute


Canadian Association of Optometrists

Canadian Ophthalmological Society


Colour blindness. Colour Blind Awareness website. Available at: Accessed December 27, 2018.

Facts about color blindness. National Eye Institute (NEI) website. Available at: Updated February 2015. Accessed December 27, 2018.

What is color blindness? American Academy of Ophthalmology website. Available at: Updated November 2018. Accessed December 27, 2018.

Last reviewed June 2018 by Michael Woods, MD  Last Updated: 12/27/2018