What is the function of "Eyebrows" in humans?

Prasannae Negalur

Eyebrows are a very significant aspect of our appearance. Eyebrows are also one of our most expressive facial features and are used for communication. But why are they there in the first place? As we evolved and lost most of the thick hair on our bodies, why did we keep that little bit over the eyes?

Scientists aren't entirely sure why we kept this hair, but they have a pretty good guess. We know that eyebrows help keep moisture out of our eyes when we sweat or walk around in the rain. The arch shape diverts the rain or sweat around to the sides of our face, keeping our eyes relatively dry. The most obvious advantage of this is that it lets us see clearly when we're sweating a lot or out in the rain.

The shape of your brow itself diverts a certain amount of moisture, but eyebrows make a significant difference in your ability to see. Diverting the sweat away is also good because the salt in sweat irritates the eyes, making them sting a little.

There are a number of ways these qualities might have helped early man survive. Being able to see more clearly in the rain could certainly help you find shelter, and there are several circumstances when keeping the sweat out of your eyes could save your life (like when running from a predator, for instance).

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