Why do we have eyebrows?
Developmentally, the eyebrows (like the eyelashes) keep moisture out of the eyes. This includes rainwater and sweat, which could be irritating in your eyes if you were running away from a predator.
More importantly to the modern human being, eyebrows have taken on a key meaning for appearance and non-verbal communication. Lifting your eyebrows can express many things depending on the appearance of the rest of your face and body.
Answered by Aneel Bhangu