Most people have three kinds of cone cells in their eyes, which are optimized, or tuned, to receive red, green, and blue light. This is trichromacy, the most common vision type among humans. With this arrangement, we can see about 1 million colors. A small percentage of the population is dichromatic, or colorblind, the result of having only two kinds of cone cells. Then there are a very, very small number of humans who have four kinds of cone cells. These people, who can see approximately 100 million distinct colors, are tetrachromats. In addition to red, green, and blue cone cells, a fourth type of cone cell is designated as yellow.
Tetrachromacy is common in many non-mammal species, notably birds and insects. It allows creatures who have the fourth cone to see much more of the light spectrum. Essentially, tetrachromatic eyesight is the ability to see 100 times more colors than trichromatic eyes can see, which may include ultraviolet light as well, depending on species and genetics.
The most famous tetrachromat in the world is Australian artist Concetta Antico. She’s been painting the world as she sees it since she was seven years old. For more than four decades, Antico knew that how she saw the world worked differently for her than anyone else she knew, but she didn’t know why. (Tetrachromacy is super rare in women, and even moreso in men.) About ten years ago, researchers who study tetrachromacy confirmed that Antico was in fact one of the very few who had the genetic variation. She’s called her ability to see what others cannot, “A kind of superpower”. The discovery made her artwork even more valuable and sought after than it was.
There are numerous videos available regarding Concetta Antico and her amazing abilities. Here are a few selections to sample if you’re interested.
“World-Renowned Tetrachromatic Artist – Concetta Antico, The Color Queen” (1:14)
“Seeing colours nobody else can – Incredible Medicine: Dr Weston’s Casebook | Episode 2 – BBC Two” (2:42)
“Can Some People See More Colors Than You?” (3:44)
“Concetta Antico Speaking & Painting at the Liberty Station” (4:44)