Eyebrow

From Wikipedia, the free encyclopedia

The eyebrow is a bony ridge above the eye that protects the eye and bears a tuft of facial hair in most mammals. The main function of the eyebrows is to prevent moisture (mostly sweat and rain) from dripping into the eye (a critical organ). The typical curved shape of the eyebrow (with a slant on the side) and the direction in which eyebrow hairs are pointed, make sure that moisture has a tendency to flow sideways of the eyes, mainly along the side of the head but also along the nose. The protruding brow ridges of modern humans could also still play a role in this process. Eyebrows also prevent debris such as dandruff and other small objects from falling into the eyes, as well as providing a more sensitive sense for detecting objects being near the eye, like insects. Eyebrows also have a facilitary function in communication, strengthening expressions like amazement or anger.