How far birds can see ?
Vision is dominant sense for birds as it helps in safe flight.
In most hunted birds that depend on vision, eyes are located to the side of the head that helps in monocular vision. It means each eye scans a separate place.
Owls eyes are placed more to the front of head that gives wider angle of binocular vision. It is important to find out the distance.
Third eyelid is also present in birds that moves sideways across the cornea and keeps it moist without any interruption in vision.
Eagles has best vision and accuracy that helps to spot and catch the prey. The eyes of eagles are placed far forwards that gives binocular or 3-D vision.