If you're a tetrachromat—which, odds are, you aren't—you can see more colors than the rest of us, thanks to an extra structure in your eyes. The structure, known as a cone, detects certain light wavelengths. With three cones, most of us can see about a million colors, while tetrachromats, who have four, can see 100 million, Popular Science reports. One such person is an artist named Concetta Antico, who explains her experience gazing at a leaf: "Around the edge I’ll see orange or red or purple in the shadow; you might see dark green but I’ll see violet, turquoise, blue ... It's like a mosaic of color."
Only about 1% of humans are tetrachromats, and it would appear that the condition is limited to women—though, the Huffington Post reports, researchers aren't certain about that. Women have two X chromosomes, and theories have suggested that the condition depends on mutations in both. Researchers have been studying Antico to learn more about tetrachromatism. Meanwhile, the rest of us can perhaps benefit from looking at her artwork: As the Huffington Post notes, her "canvases seem to burst with extra, vivid color as only she can depict." For others, the BBC reports, the condition may be a nuisance at times: One woman describes seeing major clashing in clothes others believe match. (Someone else whose vision might make you jealous: your cat.)