How many eyelids does a shark have?

4 to 6.

A shark may have 4 to 6 eyelids, or 2 to 3 eyelids in each eye. This is according to the Shark School of the San Diego Natural History Museum. A shark has an upper eyelid and a lower eyelid in each eye. Some sharks have a third eyelid, the nictitating membrane, which protects their eyes when biting prey.