The Nictitating Membrane

Order: Passeriformes

Family: Corvidae

Genus: Corvus

Species: Corvus corax

Common Name: Raven

 

Birds have a third eyelid known as a Nictitating Membrane that can be used for protection and to moisten the eye while still maintaining visibility. Humans still have vestigial nictitating membranes in the corners of their eyes.

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