What is the purpose of eyebrows and eyelashes?
Hair around the eyes has become an important way to express personal style, from slitted brows to false eyelashes. However, eyebrows and eyelashes have a purpose other than decoration. According to Dr. Stephanie Marioneaux, clinical spokeswoman for the American Academy of Ophthalmology, the primary goal of both is to safeguard the eyes. Their goal is to be another layer of protection for the actual eyeball against whatever it is  whether its liquid, whether its solid, whether its dust, whether its bugs or insects.  Marioneaux said the brows shield the eyes from pollutants such as sweat, dandruff, and rain that fall down the face. They may capture or absorb the material, or their angle may guide it away from the eyes and to the side of the face. Aside from that, the brows perform a few other purposes. For one thing, brows are important for facial expression and transmitting subtle emotions, and the ridge between the brows may have evolved to allow for more expressive brow movements, according to a 2018 virtual modeling study published in the journal Nature Ecology & Evolution. Eyelashes provide similar protection to the eyes but in a different way. Theyre almost like facial whiskers, Marioneaux added. Theyre long and sensitive. When they are touched, the blink reaction is triggered as a protective mechanism. Without the eyelashes, the blink reaction would take longer to activate because the major trigger would be seeing something arriving at the eye, according to Marioneaux. But this gives you a little bit of warning that something is in the vicinity that may actually injure the eye, she said.