The levator palpebrae muscle causes opening of the eye while the orbicularis oculi closes the eye. The Müller's muscle in the upper eyelid and the inferior palpebral muscle in the lower eyelid cause widening the eyes. These muscles are responsible for blinking, squinting and winking.

What happens when you wink?

A wink is a facial expression made by briefly closing one eye. A wink is an informal mode of non-verbal communication usually signaling shared hidden knowledge or intent.

Why does a person wink?

Why do we wink? Because the act is so subtle and takes on many meanings, the origin of winking is unknown. We wink to show affection, to spark a laugh, to share an inside secret and for so many other reasons. We wink in person, in emails and in text messages.