Is there a biological or functional reason we have hair above and around our eyes?
Eyebrows Move Moisture Away from Eyes and Help Us Communicate Non-Verbally
Our eyebrows channel unwanted moisture—sweat and rain in particular—away from the eye to help keep vision clear. The shape and direction of eyebrow hairs make it easier for moisture to flow sideways around the eyes, along the side of the head. They also help to block out light and filter dust and dirt that may fall into the eyes.
Experts also believe that eyebrows play an important role in human communication and facial expression. Eyebrows can exaggerate expressions such as happiness, surprise and anger. A study found that eyebrows may be a more recognizable indicator of identity than even the eyes themselves.
Hair loss in the eyebrows can be indicators of certain autoimmune diseases and hormonal imbalances, such as alopecia, hypothyroidism and lupus.
Eyelashes Prevent Irritation and Act as Human Whiskers
Eyelashes are unique among body hair. They are among the shortest hairs on the body with the longest lifespan and healthy lashes are believed to never go gray.
Eyelashes operate as air filters for the eye, catching dust, protecting the eye from debris that can obstruct vision or cause infection or injury. They are like human whiskers. Lashes act as sensors for objects coming close to the eye—like insects—and trigger a reflexive and protective blink. A study conducted using man-made eye and eyelash mockups, showed that lashes also reduce tear evaporation up to 50 percent, helping to keep eyes sufficiently lubricated.