Most birds of prey have eyes on the sides of their heads, but owls have large forward-facing stereoscopic eyes that enable depth perception necessary for low-light hunting.
The large eyes of an owl are for acute night vision, and they are also like pair of sunglasses.
Being nocturnal, much of their hunting is done at night, and being able to see in the dark helps a lot.
However, having large, open pupils for seeing in the dark can be a problem when the sun is out.
So Mother Nature came up with a solution for the owl.
It has a thin membrane of an eyelid that serves as a light filter during daylight so the owl can see while its eyes remain protected.
Owls are also farsighted and are unable to see anything that is close up clearly.