The Osprey Stare
The arrangement of the feathers above the osprey’s eyes serves to reduce glare from the water surface when fishing.
It also gives the osprey its characteristic menacing stare.
Nictitating Membrane
When an Osprey dives into the water, a third eyelid—called a nictitating membrane—closes immediately to protect the bird’s eyes. This semi-transparent membrane is a pale, icy-blue color and allows some areas of light and dark to be seen even underwater.
Osprey Tales 