COLOR BLINDNESS

Color blindness (more correctly called color vision deficiency) is not blindness at all, but a problem in recognizing certain colors and shades. Most people who are color-blind just have a hard time telling the difference between certain colors.

Color blindness occurs in the retina, which is located in the very back of the eye and is about the size of a stamp. It has millions of cells that are sensitive to light. Some of these cells are called cones and it is these cells that allow colors to be seen. The cone cells combine the three main colors of red, blue, and green to make the thousands of colors that a normal eye sees. Without the right chemicals in the cone cells, the main colors cannot be seen. Most people who are color-blind cannot see red or green. For example, a green leaf may look light tan or a shade of gray in color. Another and less common form of color blindness involves the colors blue and yellow. The rarest form of color blindness is when all colors look gray.

It is more common for males than females to be born with a color vision deficiency. Color blindness is almost always inherited, however, aging, certain medications, and retina or optic nerve disease may interfere with normal color vision. Some cases of color deficiency that begin later in life may be helped with surgery, such as cataract removal, changing medication, or treating the eye disease that caused the color vision deficiency. There is no cure for color blindness that has been present since birth. Wearing glasses or contact lenses with filters are available.

Anyone having trouble distinguishing between colors should see an eye doctor for an evaluation. A test is done by showing a picture made up of dots of different colors against a gray background. If the person cannot see the picture within the dots he may be color-blind.

Most children can recognize and name the colors red, green, and blue by the age of 4 years. Diagnosing color vision problems early may prevent learning problems during the school years since many learning materials rely heavily on color.

People may develop their own "systems" or can be taught to recognize colors by brightness or location. For example, for driving, the top light of a traffic signal is red and means stop, while the bottom light is green and means go. Family and friends can help by arranging closets and drawers in order of color, putting all the pieces of clothing that are the same color together. In addition, a post-it note with the name of the color written on it can be placed on the appropriate piece of clothing.

If you experience any change in your vision or in the condition of your eyes, see your healthcare provider.

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

HIL File EYES4504.RF2 VRS# 4504 Data Version 7.0