Humans have weirdly white eyes. Here’s why.
Get the Popular Science daily newsletter💡 Breakthroughs, discoveries, and DIY tips sent six days a week. By signing up, you confirm you are 16+, will receive newsletters and promotional content and agree to our Terms of Use and acknowledge the data practices in our Privacy Policy. You may unsubscribe at any time. Blue, green, amber: Someone’s eye color immediately attracts our attention. But there’s something unusual about human eyes: We have a large visible area of white that surrounds the iris. Most other mammals have entirely dark eyes with almost indistinguishable pupils. So why are we different? What is the white part of our eyes actually for? The whites of our eyes help us connect Scientists paid little attention to that question until 1997, when Shiro Kohshima, a Japanese biologist at Kyoto University, decided to take a closer look. He compared the eyes of nearly half of existing primates and found that only humans had white in their eyes. His theory was that the white part of the eye (the sclera) helps us communicate because …





