The brow ridge
The brow ridge acts like an awning to protect the eye. Similarly, the top lid extends forward further than the bottom lid.

The eyebrows sit on the brow-ridge and peak towards the outer end. The outside ends tend to be lighter, thinner, and have less hair than the inside ends. The shape of the eyebrows varies from person to person. Men tend to have fuller and straighter types while women have thinner types that peak higher.