The eyesight of dogs differs from that of humans in various ways. It even varies from breed to breed. Some dogs have a field of vision that is wider than the 180 degrees of humans.
Dogs with long noses have something called a visual streak. This means that they are able to scan the horizon very quickly, the section of their retina that stretches from one corner to the other contains photoreceptors that are extremely sensitive.
However, dogs with short noses seem to have an area centralis. This means that like humans, they have a central area that contains sensitive nerve endings. This is thought to give them better depth perception, not unlike the eyesight of humans.