the membrane also serves to protect the parents' eyes from their chicks while they are feeding them, and when peregrine falcons go into their dives, they will blink repeatedly with their nictitating membranes to clear debris and spread moisture across the eyes. Woodpeckers tighten their nictitating membrane a millisecond prior to their beak impacting the trunk of a tree to prevent shaking-induced retinal injury.

The nictitating membrane can be used to protect