Why do we have eyebrows?
Eyebrows help keep sweat, rain and dust out of the eyes, and they play a big role in communication. They help show emotions such as surprise, anger and worry.
The arch shape of the eyebrows and the direction of their hairs channel moisture to the sides of the face, away from the eyes. This helps keep vision clear when we sweat or walk in the rain. Eyebrows may also shade the eyes slightly from bright light.
Eyebrows are very important for facial expressions. Raised eyebrows can show surprise or interest, while lowered, pulled-together eyebrows show anger or concentration. Researchers have found that people often find it harder to recognize a familiar face when the eyebrows are removed in photos than when the eyes are removed.
Shaped by evolution
Some scientists think our mobile eyebrows evolved to help early humans communicate in subtle ways, showing friendliness and sympathy. Our ancestors had heavy brow ridges, but as these became smaller, eyebrows gained more freedom to move, possibly helping people build social bonds.
Did You Know?
A quick raise of the eyebrows, called the eyebrow flash, is used in many cultures as a friendly greeting when people recognize each other.
This answer is general information, not medical advice. For a personal health question, talk to a doctor.