Eyelashes Decoded: The Ideal Lash Length is Just One-Third the Width of the Eye

If short eyelashes were a concern then here is some good news. New research shows that the ideal lash length is just about one-third the eye width.

According to The New York Times, researchers at Georgia Institute of Technology studied eyelashes from 22 different species at American Museum of National History and also conducted simulation studies to learn that the one-third lash length to eye-width proportion works the best for diverting air flow around the eye, which in turn helps reduce evaporation.

"Eyelashes form a barrier to control airflow and the rate of evaporation on the surface of the cornea. When eyelashes are shorter than the one-third ratio, they have only a slight effect on the flow. Their effect is more pronounced as they lengthen up until one-third. After that, they start funneling air and dust particles into the eye," said Guillermo Amador, the study's author, in a press release.

After studying real eyelashes, researchers conducted simulations using a small container of water the size of a real eye and a mesh like structure around it to mimic eyelashes. This setup, when tested in a wind tunnel, showed that a one-third proportion of lash length to eye-width works the best.

"As short lashes grew longer, they reduced air flow, creating a layer of slow-moving air above the cornea. This kept the eye moist for a longer time and kept particles away. The majority of air essentially hit the eyelashes and rolled away from the eye," said Georgia Tech assistant professor David Hu, the study's lead.

Amador adds, "This is why long, elegant, fake eyelashes aren't ideal. They may look good, but they're not the best thing for the health of your eyes."