system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do we get crusty stuff on our eyes?
gpt
Found this on google



"the plica semilunaris, which is located around the eye. Was thought to have no function. But lo and behold, eventually it was discovered that this “useless” organ has an important function after all.

In fact, it is the “crusty” factory. It secretes a sticky mass that collects any foreign materials such as dust or pollen. All this trash is surrounded by the sticky shit so that it does not scratch the sensitive cornea in your eye. Once the garbage is collected, the plica semilunaris “escorts” it out of the eye."