Eyelashes serve as windbreak to shield eye

New York Times : Once thought to protect the eye by catching dust particles or triggering blinking, eyelashes actually serve to divert airflow away from the eye’s surface. David Hu of Georgia Tech and colleagues measured the lashes of various mammals and found that most lashes tend to be about one-third the eye width. That appears to be the optimal length to channel air away from the ocular surface, which helps to reduce evaporation and the deposition of dust, according to their study published in the Journal of the Royal Society Interface. To test lashes’ ability as a windbreak, the researchers created an artificial eye and placed it in a wind tunnel. They found that the lashes’ aerodynamic benefits decrease with increasing length—longer lashes can actually channel airflow toward the eye’s surface. The principles involved could be used to help reduce dust on sensitive sensors or solar panels.