Color blindness is a condition affecting the ability to distinguish colors under normal light or to perceive colors as they are seen by typical individuals. Usually, the condition is present at birth, but it can also be caused by injuries or a variety of eye diseases.
Color perception depends on the cones located in the eye's macula. People are generally born with three varieties of cones, each perceiving differing wavelengths of color tone. When it comes to pigment, the size of the wave is directly associated with the resulting color. Long waves produce reds, moderately-sized waves generate greens and short waves produce blues. Which type of cone is affected impacts the nature and level of the color deficiency.
Red-green color vision problems are more common in men than in women because the genes are recessive and linked to gender.
There are many cases where people acquire color blindness later in life resulting from another condition including injuries, cataracts and especially macular degeneration. However, if one of these situations were to cause color blindness, treatment of the condition may be able to improve color vision.
Optometrists use numerous exams for the condition. The most widely used is the Ishihara color exam, called after its inventor. In this test a patient views a plate with a circle of dots in seemingly random sizes and colors. Within the circle one with proper color vision can see a numerical figure in a particular color. The individual's capability to see the digit inside the dots of clashing tones indicates the level of red-green color sight.
Although inherited color vision deficiencies can't be treated, there are a few steps that can assist to make up for it. For some, wearing tinted contacts or glasses which block glare can help to perceive the differences between colors. Increasingly, computer applications are being developed for common personal computers and for smaller devices that can assist users to differentiate color better depending on their specific diagnosis. There are also promising experiments being conducted in gene therapy to correct the ability to distinguish colors.
How much color vision problems limit an individual is dependent upon the variant and degree of the deficiency. Some patients can accommodate to their condition by learning substitute cues for determining a color scheme. For instance, many learn the order of traffic lights or compare items with reference objects like green plants or a blue body of water.
If you suspect that you or your child might be color blind it's important to schedule an appointment with an optometrist. The earlier you are aware of a problem, the sooner you can help. Feel free to call our Cincinnati, OH optometry practice for additional information about color blindness.