Color blindness is a condition impacting the ability to view colors under typical light or to discern colors as they are viewed by normal people. Usually, the disorder is present at birth, but it can also be caused by old age or a variety of diseases of the eye.
The way we perceive colors is dependent upon cones found in the eye's macula. People are usually born with three types of pigmented cones, each of which perceives different wavelengths of color tone. With shades of color, the length of the wave is directly linked to the resulting color. Long waves produce red tones, moderately-sized waves are seen as greens and shorter waves are perceived as blue tones. Which type of cone is affected impacts the spectrum and severity of the color deficiency.
Because it is a gender-linked recessive trait, green-red color deficiency is more common in males than in females. Nevertheless, there are a small number of females who do experience varying degrees of color vision deficiency, particularly yellow-blue deficiencies.
Some people acquire color blindness later in life as a result of another condition including macular degeneration, cataracts and glaucoma. However, if one of these situations were to cause color blindness, treatment of the condition may be able to restore color vision.
There are several tests for color blindness. The most common is the Ishihara color exam, named after its inventor. For this test a patient views a plate with a circle of dots in different colors and sizes. Inside the circle appears a numerical figure in a particular tint. The patient's ability to make out the number within the dots of contrasting tones indicates the level of red-green color blindness.
While inherited color vision deficiencies can't be corrected, there are a few measures that can help to make up for it. Some evidence shows that wearing colored contacts or glasses which block glare can help people to see the distinction between colors. Increasingly, computer applications are on the market for standard PCs and even for mobile machines that can help users differentiate color better depending upon their particular condition. There are also promising experiments being conducted in gene therapy to improve color vision.
How much color blindness limits an individual is dependent upon the variant and degree of the deficiency. Some patients can adapt to their condition by learning substitute cues for colored objects or signs. For instance, they can learn the shape of stop signs rather than recognize red, or compare items with reference objects like the blue sky or green trees.
If you suspect that you or your child could be color blind it's important to get tested by an optometrist. The earlier a diagnosis is made, the sooner you can help. Contact our Olathe, KS optometrists to schedule an exam.