Nictating Membranes

Ravens, like other birds and many other animals, have a third eyelid or nictating (or nictitating) membrane. When it covers the eye it gives it a milky appearance.

I have usually avoided posting pictures where the nictating membrane is exposed. Today I decided what the heck and I posted some. Perhaps I did this because they were decent images or perhaps just because there is no use in pretending that the eyes of ravens are always uncovered.

Nictating membrance half open