Why don't prey animals have eyes in the backs of their heads?
Prey animals often have eyes on the sides of their heads to give them a wide field of view - but eyes in the back of their heads would be counterintuitive.
Asked by: Alan Hatchard, Bristol
Animals need to know where they are going, so they must have eyes that look forwards. If they also had eyes on the backs of their heads, the brain would have to combine these two totally different views into one, including opposite directions of movement.
A simpler solution, found in many prey animals, is to have eyes on the sides of the head to give a very wide field of view. Rabbits, for instance, have eyes high up on the side of the head. The disadvantage is a small blind spot right in front of them. Goats, however, have horizontal pupils that allow them to see 320° with no blind spot.