The Senses

Most dogs do have good eyesight. Vision is important because the communication world of the dog is based on body postures and signals, e.g. ear positions, tail positions, lip displays, raised hackles on the back of the neck. Dogs rely heavily on their sense of sight in conjunction with their sense of smell for survival.

Dogs see differently from people. They tend to be short-sighted as their eyes are flatter and they cannot change the shape of their lenses, like people, in order to alter the focal length. This means that they are unable to focus on the shape of an object. What is clear to us will appear blurred to them. It is estimated that dogs can see at 20 feet what people can see clearly at 75 feet. Dogs are more efficient at detecting movement- which usually indicates potential prey or danger. They see objects first by movement, then by brightness, then by shape, which is why you should approach a dog slowly from the front first.

Dogs have better low-light vision than people. This is due to the tapetum lucidum, which is a glistening opaque layer that reflects light back to the rods and cones in the eye. This causes their eyes to flash in headlights.

Can they see in colour? Receptor cells called cones are necessary for this. Dogs have fewer cones than people and more rods (light sensing cells), which indicates that they see a smaller range of colours, although brighter. Research indicates that dogs are most likely see shades primarily in blue and yellow. Guide dogs work from the height of the traffic lights rather than differentiating between the red and green lights.

Some people are certain their dogs watch the television. One owner even said his dog seemed to be hooked on Caesar Millan's the Dog Whisperer! It is true to say that dogs can see flickering light better than people can, however, the television frequency of 625 dots per second transformed into a visual image is likely to come across to a dog as a screen full of fast moving dots. Therefore, it will be the noise on the screen rather than the picture that a dog will respond to. The most important point to remember is that your dog's view of the world stems from about 12 inches off the ground, a much different perspective to ours!