People spend a lot of money to make their eyelashes look long, thick and dark to appear more alluring. But whether you have “Bette Davis eyes” or not, your eyelashes serve a greater purpose beyond just accentuating beauty–they play a very important role in protecting your eyes.

Reduce airflow

All mammals have moist eyes. This is due to the tear film that protects the eye, provides nutrients for the eye, and refracts light. Airflow can cause the eyes’ moisture to evaporate and can blow irritating dust and deposits into the eyes so eyelashes serve to minimize the flow of air over the eyeball. According to a study published in the Journal of the Royal Society Interface, it turns out that the eyelashes of mammals, regardless of whether they’re a 1-pound hedgehog to a 1,100-pound giraffe, are invariably one third the length of the animal’s eye.

Keeping moisture out

In addition to keeping the moisture in your eyes in by reducing airflow, eyelashes also help by keeping moisture, like sweat or rain, out of your eyes. Their curved shape and specific position catch and redirect it away.

Filter sunlight

Too much sunlight can be harmful to your eyes. Although they don’t filter out all the dangerous rays, and sunglasses are still very necessary for eye protection, eyelashes help to shield your eyes from the bright light of the sun.

Alert for danger

Just like a cat’s whiskers, eyelashes act as sensors to let the brain know a potential danger could be imminent. If something comes in contact with your eyelashes, it causes an eyelid-closing reflex.

Some people believe when an eyelash falls out onto your cheek and you blow it away it can grant a wish. Whether this is true or not, we cannot say, but given the many ways in which these tiny, seemingly insignificant hairs can keep your eyes safe, it’s not surprising why many think they are magical.

 

Sources: http://wonderopolis.org/wonder/why-do-we-need-eyelashes/