Caroline McCarty

Have you ever wondered what the white part of your eyes is called? It’s called the sclera. And it seems to be teaching us magnitudes about ourselves and our past as an evolving race. As humans, we have the biggest ratio of visible sclera to iris compared to all other primates. It is easy to notice the lack of visible sclera in other animals, as well. Some animals, lizards and horses, for example, can have a black sclera.

Japanese researchers Hiromi Kobayashi and Shiro Kohshima have deduced that we have such a visible “white of the eye” to enhance our communication abilities. As humans, not only do we have a larger ratio of visible sclera, we also have a much larger horizontal eye outline. This characteristic allows us to better read a person’s gaze and, thus, grants us the ability to better understand each other.