Anatomy: Nictitating Membrane

Great horned owl blinking its thrid eyelid (photo by Chuck Tague) This great horned owl is winking sideways! He’s closing his nictitating membrane. The nictitating membrane, or third eyelid, is named for the Latin word “to blink” (nictare).   Its function is to protect and moisten the eye while allowing the animal to see.  Sometimes the … Continue reading Anatomy: Nictitating Membrane