Published December 07, 2011
Color blindness is a slightly misleading term because people who are colorblind can still see colors. However, most people with color blindness have deficiencies distinguishing between red and green or between blue and yellow. Here is a guide to understanding the nature of color blindness:
Color blindness is a fairly widespread condition, affecting approximately one in 10 men, according to the U.S. National Library of Medicine. These people have trouble distinguishing between seeing different hues and brightness. The symptoms can be so mild that a person may not even know he or she is color blind. Many people adjust easily to color blindness, and it is usually considered a mild disability. Nonetheless, some important tasks, like driving or learning to read, can be significantly more challenging with color blindness.
Types of color blindness
There are three categories of color blindness: monochromacy, dichromacy, and anomalous trichromacy. People with monochromacy actually are colorblind, and they can only see shades of black, white and gray. Those with dichromacy can distinguish between different hues, but they may have trouble telling between red and green or between blue and yellow. Finally, individuals with anomalous trichromacy are the most able to distinguish between hues, but their color vision is still imprecise. There are a number of non-invasive tests to determine if someone has color blindness and what kind it is. One of the most popular diagnostic tools is a number written in colored dots, set against a background of a different color. While most people can recognize the number easily, those with color blindness would find it difficult or impossible.
The eye is mostly made up of rods and cones, and color blindness is a result of an abnormality with the cones. Rods are used mostly for night vision, while cones contain pigments used to detect colors. If the cones are missing even one pigment, they misinterpret color wavelengths and color vision ends up distorted. Color blindness is primarily a genetic condition. Men make up the vast majority of people with color blindness, suggesting that there is a sex-linked trait. While it is a rare occurrence, there are times when color blindness is acquired instead of genetically inherited. Acquired color blindness can be caused by aging, eye issues like glaucoma or cataracts, or an eye injury. There are also some medications that can cause color blindness as a side effect.
There is currently no known treatment for inherited color blindness. However, there are ways to help augment deficient color vision. Some people opt for glare-reduction glasses or colored contacts, both of which could help with distinguishing hues and brightness. Colored contacts are not for everyone, though, because they can also distort vision. For people with acquired color blindness, surgery can restore color vision.