Birds of prey, such as eagles, hawks and buzzards, have the sharpest eyesight in the animal kingdom. It is thought to be up to eight-times sharper than human vision, enabling them to spot prey from 1.5 kilometres (0.93 miles) away. This is partly because their eyes are especially large for the size of their heads and feature five times as many light sensitive cells as ours do, allowing them to see objects in much greater detail. They also have special muscles surrounding their eyes that cause the lens to curve, making it possible for them to adjust their focus as their prey moves.

In addition, their superior colour vision means they are capable of discriminating between more shades and can see ultraviolet light, which is invisible to the human eye. This enables them to spot the urine trails of small prey as they reflect UV light, leading the birds to their next meal