Question

how is the vision of birds like owl or crow different from human?

Answer 1

The night vision of owls is 100 times as keen as that of human beings, because their eyes are especially adapted for seeing in the dark. They are however colour blind as they have more no of rod shaped receptor cells than cone shaped ones. Operating in bright light, cone cells sharpen details and react to color.as a result they see the objects as blurred due to lesser no of cone cells. Rod cells gather light and owls have 10 times as many of these as do human beings. .Owls have exceptionally large eyes and can control the amount of light entering by expanding or contracting the pupil. Each pupil can act independently of the other so that owls can see objects in the shadows and in bright light at the same time. Owls eyes are so large that they are supported by thin, bony, tubular structures called sclerotic rings. Which makes their eyes immovable and nature has compensated for this by giving owls extremely flexible necks, which enable them to turn their heads through an arc of 270 degrees.These birds have excellent binocular vision as their eyes are in the front of their heads. This gives them a tremendous advantage in swooping on small lively prey, because distance judgment depends on binocular vision. To add to their advantages at night, the owls have outstanding hearing.