❓ why
Why do we have eyelashes?
human bodybiology
Quick Answer
Eyelashes protect eyes from dust and debris and trigger a protective blink when something touches them.
The Full Story
Lashes are highly sensitive, so a light touch triggers the blink reflex. A 2015 study from Georgia Tech found that eyelashes about one-third the width of the eye reduce airflow over the eye's surface. This cuts evaporation of tears and the amount of dust landing on the eye by roughly half. Longer lashes actually work less well, funnelling more air toward the eye.
Key Facts
1.The upper lid typically has around 90–160 eyelashes; the lower lid has fewer.
2.An individual eyelash lasts a few months before falling out.
3.The 2015 study measured lashes in 22 mammal species.
YouTube Angle
Suggested video title for this topic:
"Eyelashes Are Perfectly Designed — Here's Why"