The inability to perceive colors or color blindness is typically a innate condition which impairs one's ability to differentiate among shades of color. Color blindness is caused by a deficiency in the cones in the eye's macular area, generally impacting a viewer's ability to differentiate varieties of red or green, but occasionally influencing the ability to see additional hues too.
Color perception is dependent upon cones located in the eye's macula. Humans are generally born with three kinds of cones, each of which perceives various wavelengths of color tone. The size of the wave is directly related to the resulting color. Short waves produce blues, middle-sized waves are perceived as greens and longer waves produce reds. The pigmented cone that is missing impacts the nature and level of the color blindness.
Because it is a gender-linked recessive trait, green-red color deficiency is more common in men than in women. Still, there are a small number of women who do experience some degree of color blindness, particularly yellow-blue color blindness.
Rarely, there are cases where individuals develop color vision problems later on as a result of another condition including macular degeneration, aging and medicinal side effects. However, if one of these situations were to cause color blindness, treatment of the condition may be able to improve color vision.
There are several evaluation methods to diagnose the condition. The most common is the Ishihara color exam, called after its designer. For this test a plate is shown with a circle of dots in seemingly random sizes and colors. Inside the circle appears a numerical figure in a particular color. The individual's capability to see the number inside the dots of clashing shades indicates the level of red-green color vision.
Even though genetic color vision deficiencies can't be treated, there are some options that can assist to make up for it. For some, using tinted contacts or glasses which minimize glare can help people to see the differences between colors. More and more, computer applications are on the market for common computers and even for mobile machines that can help users distinguish color better depending on their particular condition. There is also interesting research underway in gene therapy to improve the ability to perceive colors.
The extent to which color blindness limits a person depends on the variant and degree of the condition. Some patients can accommodate to their condition by familiarizing themselves with alternate clues for colored objects or signs. For instance, one can try familiarizing oneself with the shapes of stop signs (rather than recognizing red) or comparing objects with color paradigms like green trees or the blue sky.
If you notice signs that you or your child could have a color vision deficiency it's advised to see an optometrist. The earlier a diagnosis is made, the sooner you can help. Feel free to call our Phoenix, AZ optometrists to schedule an exam.