Ever wonder if Fido prefers a blue toy over a pink toy? Believe it or not, he doesn’t. Man's best friend is colorblind but fortunately his survival does not depend upon the ability to see colors. His keen sense of smell compensates for his inability to see colors and enables him to differentiate between objects. Extensive scientific testing on dogs supports the conclusion that they live in a colorless world, though there is some evidence that they may be sensitive to blue and green light. The testing done primarily has focused on the dogs' responses to colors for food. The enlisted dogs were unable to tell the difference between the signal for food (one color) and that which was not for food (another color). The same tests were conducted on cats and, not surprisingly, our feline friends produced similar results.

Birds on the other hand have exceptional color vision and it is widely believed that it may be better than our own. Up until the early 1970s it was thought that birds had tri-chromatic (3 color) vision. After several studies, it has been accepted that the avian eye, not the human eye, is the quintessentialcolor vision system.

Why is it that dogs and cats have such poor color vision and birds have such superior color vision with humans (and monkeys!) somewhere in between? It has to do with the number of cones, or cells, that make up the retina of the eye. Dogs and cats only have two cones, leaving them with mostly monochromatic vision.

Birds however, have four (or sometimes more) cones, allowing them to see not only more colors or hues, but more saturated color. We, as humans, fall into the middle with three cones, allowing us to see a variety of colors yet not quite as many as birds. So the next time you go shopping for a dog, cat or bird toy for your pet, remember that while Fido or Kitty may not have a preference, Polly may prefer something to match her feathers!