Did you know – owls have three eyelids?

Yes, they have three eyelids (per eye).

They have a normal upper lid that closes downwards when the owl blinks, a lower lid that closes upwards when the owl is asleep and a third translucent eyelid that closes diagonally across the eye to moisten and protect it while maintaining vision.

This third eyelid is called a nictitating membrane and can be seen in the left hand side eye of this Spotted Eagle Owl.

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Spotted Eagle Owl (Bubo africanus) with nictitating membrane (left hand side eye) in mid blink.

This photo was taken at Eagle Encounters at the Spier wine farm outside Stellenbosh, Western Cape, South Africa.

A comprehensive owl website;  the Owl Pages.

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