But do they need supervision? Discover reports on the the rare humans who can see colors the rest of us can’t:
Living among us are people with four cones, who might experience a range of colors invisible to the rest. It’s possible these so-called tetrachromats see a hundred million colors, with each familiar hue fracturing into a hundred more subtle shades for which there are no names, no paint swatches. And because perceiving color is a personal experience, they would have no way of knowing they see far beyond what we consider the limits of human vision.
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While color-blind men had two normal cones and one mutant cone, [Dutch scientist HL] De Vries knew that the mothers and daughters of color-blind men had the mutant cone and three normal cones—a total of four separate cones in their eyes. He suspected the extra cone could be why the women perceived color differently—not because they saw less than most people but because they saw more.
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In 2007 [neuroscientist Gabriele] Jordan, now at Newcastle, returned to testing using a new method. Sitting in a dark room, peering into a lab device, women saw three colored circles flash before their eyes. To a trichromat, they all looked the same. To a tetrachromat, though, one would stand out. That circle was not a pure color but a subtle mixture of red and green light randomly generated by a computer. Only a tetrachromat would be able to perceive the difference, thanks to the extra shades made visible by her fourth cone.
Jordan gave the test to 25 women who all had a fourth cone. One woman, code named cDa29, got every single question correct. “I was jumping up and down,” Jordan says. She had finally found her tetrachromat.
What can you see, cDa29? WHAT CAN YOU SEE?