Great Horned Owl with chick in nest off entrance road. Here the left eye is open, but it still doesn't look right.
To protect their eyes, Owls are equipped with 3 eyelids. They have a normal upper and lower eyelid, the upper closing when the owl blinks, and the lower closing up when the Owl is asleep. The third eyelid is called a nictitating membrane, and is a thin layer of tissue that closes diagonally across the eye, from the inside to the outside. This cleans and protects the surface of the eye.
Perhaps the nictitating membrane is just closed. But all shots look this way.