Other forms: nictitating
When you quickly shut and open your eyes, you nictitate — which is a fancy way of saying that you blink.
The word nictitate comes from the Latin word nictare, which means "to blink." Many animals, including cats and some birds and reptiles, have a special nictitating membrane on each eye — an extra eyelid that moves sideways to protect, clean, and moisten the eye. The next time you see a lizard's eyes flicker or a bird blink rapidly, you can impress your friends by telling them it's nictitating!