The position of the eyes on the head also varies amongst animals. Eye position controls the extent of the field of view when the head is stationary, and also the possibility and extent of binocular vision. When the eyes are on either side of the head, the view is almost panoramic, but there is a loss of stereoscopic depth perception. Hunting animals tend to have a broader field of binocular vision. Hunted animals tend to have a far broader field of view.
Hunters tend to have a much larger 'blind area' behind the head than hunted animals do.
A dog has a total field of view of about 280 degrees, 180-190 degrees for each eye and 90 degrees of binocular field. Some humans can distinguish 250 colours. Whilst some mammals are colour-blind, birds probably see more colours than we do. The desert ant has the most refined colour system amongst insects and can discriminate between colours we can't see. As we age our lenses grow more yellow and filter out some of the violet.