why do birds have eyes on either side of their head
Bird vision Most birds cannot move their eyes, although there are exceptions, such as the great cormorant.[3] Birds with eyes on the sides of their heads have a wide visual field, useful for detecting predators, while those with eyes on the front of their heads, such as owls, have binocular vision and can estimate distances when hunting.[4] The American woodcock probably has the largest visual field of any bird, 360° in the horizontal plane, and 180° in the vertical plane.[5]
Monocular deprivation David Hubel and Torsten Wiesel (who won the Nobel prize in Physiology for their elucidation of receptive field properties of cells in primary visual cortex) first performed the technique in felines.[1] Cats (or kittens), although less-closely related evolutionarily to humans even than rodents, have a remarkably similar visual system to humans. They found that ocular dominance columns (the orderly clustering of V1 neurons representing visual input from one or both eyes) were dramatically disrupted when one eye was sewn shut for 2 months. In the normal feline, about 85% of cells are responsive to input to both eyes; in the monocularly-deprived animals, no cells receive input from both eyes.[2]