People often use the term color blind to describe trouble seeing certain colors. The medical term for this problem is color vision deficiency.
Most people with color vision deficiency can see certain colors. Usually, the difficulty involves distinguishing between shades of red and green. Less often, the condition causes problems with blues and yellows. Very rarely, people with color blindness see the world in black, white, and gray.
In most cases, people with this condition inherit it through a faulty gene. Because of the way this gene is passed down from one family member to the next, color vision deficiency is much more common in men than in women.
Among whites, about 8 percent of boys and men and 0.5 percent of girls and women have red-green color vision problems. The condition is less common in African-Americans and people of Asian descent.
Genetics isn't the only cause of color vision problems. Advanced age and taking certain medicines can make identifying colors more difficult. These medical conditions also can lead to color vision problems:
Parkinson's and Alzheimer's diseases
Symptoms of color blindness vary according to how the cones—the parts of the eye within the retina that detect color—are affected:
You may have difficulty distinguishing reds and greens; both colors may show up as gray.
You may have a similar problem with blues and yellows; these, too, may look gray.
You may not be able to see any colors other than black, white, or gray.
If you think you may have color blindness, an eye doctor will likely use special pictures to diagnose it. These typically look like circles containing hundreds of dots of different sizes. Some of the dots have a different color than the others and are arranged to create a number or figure. If your color vision is normal, you will be able to identify the number or figure; if your color vision is impaired, you won't be able to.
Your eye doctor may also ask you to use a special device that requires you to try to match two colored lights on a screen.
Color vision deficiency that is inherited is not curable. But special tinted contact lenses can offer some help in seeing the difference between colors.
Also, if another condition is affecting your color vision, treating that ailment may help you see colors better.
Label clothing with the help of a loved one or caregiver to enable you to choose outfits correctly. You may also want to memorize where certain colors appear, such as the pattern on a traffic light.