Eyelid shutters regulate information entering the nervous system and focus attention.

“Now it should make perfect sense that these shutters on the front of your eyes, they aren't just there for winking, and they aren't just there for cosmetic purposes. They are there to regulate the amount of information going into your nervous system. And they are there to regulate how long you are bringing information into your nervous system and in what bins. How widely or finally you are binning.”