What Is Color Blindness?
Color blindness is considered a mild disability. However, for some people, the disability can seriously inhibit job performance. For instance, many people with red-green color blindness are unable to become commercial airline pilots, physicians with color blindness have trouble differentiating blood from bile, and color blind chefs have trouble telling whether meat is cooked.
Ninety-nine percent of people (mostly men) who are color blind have a problem with their red and green cones. Cones are photoreceptor cells located at the back of your eye in a layer of cells called the retina. Cones transmit color information to the visual-processing center in the back of the brain (occipital lobe). There are 3 types of cones: red, blue and green. The vast majority of people have no problem seeing blue or yellow.
In most people who are color blind, the wavelengths at which the red and green cones absorb information overlap. Depending on the increased degree of overlap, the ability for a person with red-green color blindness to differentiate color decreases. Thus, people who are color blind appreciate a diminished spectrum of color. About 75 percent of people who are red-green color blind are green deficient, and the rest are red deficient. Very few color blind people have the complete inability to see red or green.
Depending on the type of red-green color blindness, people have trouble seeing shades of red or green, oranges, browns, pinks, purples, greys, and even black. Eyewear maker, EnChroma, has developed eyeglasses which to a limited extent dial up the contrast of red and green and make these colors more vibrant and better discernible.
How Do EnChroma Lenses Work?
EnChroma is a tinted plastic lens which is coated in about 100 layers of dielectric material. This material filters out and reflects some of the wavelengths that overlap in red-green color blindness. Using multi-notch filters, EnChroma lenses effectively drive a wedge in areas of optic interference in order to enhance the perception of reds and greens. In this way, EnChroma lenses make reds and greens and colors containing reds and greens more vibrant.
Unfortunately, EnChroma is no cure for color blindness and has its disadvantages. First, like prescription glasses, EnChroma is an optical device and not a permanent fix. Second, EnChroma lenses don’t improve global color contrast to the degree that a person could pass a color blindness test (the Ishihara test). Sure, if you’re color blind, you may better appreciate the orange traffic cone or lavender flower as more vibrant and get a taste of what it’s like to truly appreciate colors with red and green undertones. You may even be able to guess that these colors are orange and lavender. But, unfortunately, EnChroma’s effects won’t greatly improve day-to-day functioning. Third, EnChroma, like any pair of glasses, alters the vision in a global sense, and this global effect hinders any improvement in overall contrast. Fourth, EnChroma needs 30 minutes to take full effect.
In addition to EnChroma, other manufacturers are also working on other lenses and software that will help people with color blindness differentiate color. We’re still far, however, from the best solution. A solution that will help people with all types of color blindness, works immediately and selectively and adds a lot of contrast. In the meantime, if you or a loved one has red-green color blindness—or just want a pair of sunglasses that increases color vibrance—you may want to check out EnChroma lenses.
