Color me awestruck: how colorblindness glasses work

The healthy human eye differentiates approximately 10 million different colors. However, an estimated 300 million people in the world live with colorblindness, also known as color vision deficiency. In fact, 1 in 12 men and 1 in 200 women are colorblind.

Usually, colorblindness is an inherited disorder, and most people are born with it. But certain diseases, medications and even the aging process can cause someone to lose their ability to recognize the wide range of colors that healthy eyes see.

Risk factors for color vision deficiency include:

• Being male

• Experiencing trauma

• Drug use

• Having diabetes, Alzheimer’s disease, Parkinson’s disease or leukemia

• Chronic alcoholism

• Having certain eye conditions, such as glaucoma or macular degeneration

What causes colorblindness?
There are two types of cells that detect light in the retinas of your eyes: rods and cones. Rod cells detect light and dark, and cone cells detect red, green and blue colors. If one or more of these cone cells are not working or are missing, a person will experience colorblindness ranging from mild to severe.

For some people, colorblindness glasses may help. According to the American Academy of Ophthalmology, color-correcting eyeglasses may improve contrast between some colors for people with milder forms of red-green colorblindness, the most common form of color vision deficiency.

“Colorblindness glasses are relatively new, with the first pair being sold in 2012,” says Dr. Gayle Howard, a board-certified ophthalmologist affiliated with Sharp Community Medical Group. “They work to enhance the colors that a person has trouble perceiving, giving them a wider range of colors they can see.”

How do colorblindness glasses work?
Lenses for colorblindness glasses are made with minerals that filter out some of the wavelengths between green and red. A portion of the light rays coming through the lenses are blocked, reducing the overlap of the red and green light wavelengths. This allows the brain to receive a clearer signal to help distinguish between the two colors.

Dr. Howard reports that the glasses will not give people with colorblindness a true equivalent of natural color vision. Additionally, those who wish to use them to improve their color vision must be able to perceive some of that color on their own. A person with complete colorblindness would not be helped by the glasses.

“Studies in people with a mix of types of colorblindness have only shown a limited benefit, with many people unable to tell any difference,” Dr. Howard says. “More studies need to be done as companies continue trying to improve the glasses.”

If you are experiencing color vision deficiency, talk with your ophthalmologist. While there is no treatment for congenital colorblindness, specialty glasses or contact lenses may help.