Do you see color like everyone else?

Most of us have the ability to perceive a million different colors. This is due to the presence of three types of cones in our eyes that send color messages to our brain. But there are some people who have a faulty cone or only two cones which can greatly decrease color perception. This condition is known as color blindness and is very common–approximately 8% of men worldwide and 0.5% of women. Many do not realize there are different types of colorblindness. Read on to learn about the different variations:

Red-Green Color Blindness

Normal color vision is known as trichromacy–tri because it uses all three types of cones correctly allowing us to see so many brilliant colors. Take one cone away—go from being what scientists call a trichromat to a dichromat—and the number of possible combinations drops to 10,000. Most colorblind people are men because the genes involved in color vision are on the X chromosome of which men only have one. The most common form of colorblindness is known as red-green color blindness and is actually a grouping of a few disorders with similar effects on vision. A reduced sensitivity to red light due to missing or defective L-cones (or long wave cones) is known as protanopia or protanomaly respectively and a reduced sensitivity to green light due to missing or defective M-waves (or medium wave cones) is known as deuteranopia or deuteranomaly respectively. These types cause difficulty distinguishing between reds, greens and oranges and cause blues and yellows to stand out.

Blue-Yellow Color Blindness

Absent or weakened s-cones (or shortwave cones) is a condition called Tritanopia or Tritanomaly respectively. Both are extrememly rare, affecting 1 in 30-50,000, and alter the ability to distinguish some blues from greens and some yellows from violet.

Total Color Blindness

There are some who can not see any color at all–to them the world is a black and white movie. This is known as monochromacy or achromatopsia and is due to non-functioning or absent retinal cones. Achromatopsia is extremely rare occurring in approximately 1 out of 33,000 people.

Color blindness is mostly inherited, though acquired color vision defects can be caused by some chronic illnesses, accidents, chemicals or medications. There is currently no cure for color blindness, though there has been some progress with gene therapy in monkeys. If you think you may have some color vision deficiency, see your eye doctor. He or she can give you the Ishihara Plate test, the one with all the colored dots, or use more sophisticated testing if needed to find out if you are indeed color blind. If you’re a woman and you think you see colors differently, you may be one of the rare cases of women with a fourth cone known as tetrachromacy. If this is the case, you may be able to see 100 times more colors than the rest of us!

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