Bellaire Eye Care

WHAT IS COLOR BLINDNESS (also referred to as color deciciency)?

When someone is diagnosed with color deficiency it is from an inherited defect or an acquired problem. The inherited color defect is not curable and will not change over time. It is also seen in both eyes when tested individually. Color deficiency that is acquired because of some disease process may only be seen in one eye and may change or improve as the disease process changes.

INHERITED COLOR DEFICIENCY

The most common type of color deficiency is the red-green type, which is an X-chromosome linked recessive trait. It is most commonly found in males.Approximately 1 out of 12 males manifest this color vision defect. Females can also be color deficient only if the father has the color defect and the mother is a carrier or has the color defect.

When the color receptors, called cones, in the retina are defective then there is a reduced ability to recognize and discriminate colors, individuals will perceive colors differently from those who have normal color vision. Color deficiency can vary in severity from total color blindness (very rare) to nearly normal.

THE CLASSIFICATION OF COLOR BLINDNESS

Most individuals fall into the category red-green defective. We can test individuals with the Ishihara Plate Test, which allows us to diagnose if a person is red-green defective. Color deficiency can be further classified into more specific categories; however the confusion of colors and the problems experienced are relatively the same for the various forms of red-green deficiency.

WHAT A PERSON WITH RED-GREEN DEFICIENCY SEES

Patients with red-green deficiency confuse the colors red, orange, yellow and green. Blues and purples are confused because the red component in purple is reduced. Tans and browns are sometimes confused with dull green. Dull yellow or orange next to green objects may be called red or called green when next to red objects. In some forms of red-green deficiency the brightness of reds is reduced which can be helpful when deciding if something should be called red; this can also be a problem when judging red based on brightness when the surrounding light is reduced. A blinking red light in the rain is one example. In the more severe cases of red-green deficiency the patients often sees only two colors blue and then the remaining colors green, yellow, orange and red are labeled the same. They differ only in their saturation, this means red may be a richer color as compared to green, and yellows and oranges are somewhere in between.

CAN COLOR DEFICIENCY BE TREATED?

There are no treatments for the inherited form of color blindness. However, many patients with color deficiencies respond very well to the use of different colored filters to improve their color perception. These filters enhance the color differences that are normally confused. The filters are available in both glasses and contacts. If you would like more information regarding colored filters to improve your color deficiency, contact Dr. Stacy Sonik for more information.

Top of Page