Blinking is the rapid closing and opening of the eyelid. It is an essential function of the eye that helps spread tears across and remove irritants from the surface of the cornea and conjunctiva.

Blinking is controlled by a “blinking center” of the globus pallidus of the lenticular nucleus – body of nerve cells between the base and outer surface of the brain. The average length of a blink is 100-400 milliseconds.