BIG BIRD!

Cinereous Vulture (Aegypius monachus); looks blind, doesn't it?  It's not.  What you're seeing is the birds nictitating membrane.  The name comes from the Latin meaning "to blink."  If you observe a bird blinking you will often see this membrane as a 3rd eyelid.  It is transparent or translucent and is drawn across the eye with each blink to moisten it while maintaining vision. Flying birds often draw it across their field of view to exclude dust, etc. while moving.  If you photograph a lot of birds you will come to notice it...and if your shutter speed happens to catch it across the eye during a blink, either all the way, as in this case, or halfway across it looks rather silly.....and it is Silly Saturday.
~
This vulture lives at the zoo in Milwaukee but is normally a Eurasian bird and the largest of the vultures.  It has a wingspan of 8-10 feet (2.4-3m) and females can weigh over 30 pounds (14kg) with the males about 25 pounds (11kg).  It's typical of raptors that the females are the larger of the species.
~
Here's some interesting information about these birds:

https://www.youtube.com/watch?v=3_tf9O73vB8

~
Best viewed in Large