(Hat tip: slashdot)
Check out this fascinating article on tetrachromats — women able to process colors from four, distinct sensors (cones) instead of the three found in most humans (and all men). The article, “Some women may see 100 million colors, thanks to their genes,” notes that “2 percent to 3 percent of the world’s women may have the kind of fourth cone that lies smack between the standard red and green cones, which could give them a colossal range.”
That means “there could be 99 million women in the world with true four-color vision.”
It may be impossible for us trichromats to imagine what a four-color world would look like. But mathematics alone suggests the difference would be astounding, said Jay Neitz, a renowned color vision researcher at the Medical College of Wisconsin.
Each of the three standard color-detecting cones in the retina — blue, green and red — can pick up about 100 different gradations of color, Dr. Neitz estimated. But the brain can combine those variations exponentially, he said, so that the average person can distinguish about 1 million different hues.
A true tetrachromat has another type of cone in between the red and green — somewhere in the orange range — and its 100 shades theoretically would allow her to see 100 million different colors.
That may be why Mrs. Hogan can look out the windows of her Mount Washington home and tell the relative depths and silting of the three rivers at the Point by discerning the subtle differences in their shades.
“I have a very hard time even giving names to colors because I see so many other colors inside them,” she said.
The article also discusses four-color vision in other animals and color-blindness in men. The fact that some men are color-challenged while some females possess super-color-vision, may help explain why men suck at matching clothes and interior decorating (ok, I just made that up).
Also, see this related article that discusses how mice transgenetically altered with a single human gene are then able to see in full tri-color vision.