ELi5: How is it that my eye is able to close before something splashes into it?

Question

Do my eyes see something coming (reflexes can’t be that fast right?) or does it hit my eyelashes or something (still fast reflexes??)?

In: Biology

Answer 1

The same way you might flinch if something was coming your way, your brain can react before you consciously think to react. Reflexes can indeed be that fast, especially the blink reflex – merely a fraction of a second.

With that said, your eyelashes are meant to protect your eyes and can likewise signal to protect your eyeballs if they come into contact with something unanticipated, much like the way nose hairs are meant to protect your nasal passage but getting past that first line of defense could lead to a sneeze reflex.