Please do not send questions if you are not a subscriber. Please use the search engine or one of the indexes to see if the information you need is already online. Please see Subscriber info for details. How dogs see Dogs can see in much dimmer light than humans. The rods need much less light to function than cones do.
Dogs can detect motion better than humans can.
Dogs can see flickering light better than humans. The only significance to this appears to be that dogs may see television as a series of moving frames rather than as a continuous scene. An object a human can see clearly may appear to be blurred to a dog looking at it from the same distance. This means that they can see at 20 feet what a normal human could see clearly at 75 feet. Humans have trichomatic vision, meaning that they can see the whole sprectrum.