Owl eyes are huge but can’t move
Accounting for roughly five per cent of the bird’s weight, the eyes of an owl are around 250-times larger than those of a human in relation to their body size. The cornea and pupil are enlarged to let in as much light as possible as most owls are nocturnal. Their eyes have very few colourdetecting cone cells but a huge array of low-light rods. Owls are able to see very clearly over long distances but struggle to detect objects very close to the eyes. They are adapted for hunting small prey from the air throughout the night.
Even though the eyes are highly specialised to work well in the dark, owls cannot move them in any direction. They are held in place by bony structures called sclerotic rings, fixed looking straight ahead. This is why owls are able to turn their necks as far as 270 degrees in either direction.