The eyes are simply the dogs most expressive feature. The doleful expression on Rovers eyes would be very hard to ignore. The imploring look would urge the pet owner to reach for a slicker and brave the pelting cold rain just to take the dog outside for its nightly visit to its own bathroom. The placement of the eyes enables the dog to have wider angle vision. As long as a dog is on duty, humans can sleep soundly at night. The eyes of dogs have an abundance of rods, the light sensitive cells that adapt to dim light and allows dog to see better in the dark. Because of the long association with dogs, humans tend to give the pet human characteristics. Dogs are dressed in colorful and trendy doggie costumes. Dogs are provided with colorful toys as well. But can dogs see color? Does the dog appreciate the red chew toy, the green blanket? Dogs were once believed to be color blind. Studies though have confirmed the dogs ability to see color.
Our furry friends are thought to see only black and white and various shades of gray. This notion was refuted after various studies on canine vision were made. In 1980s, a research conducted in University of California by Jay Neitz. Although canine vision is less detailed and less intense as compared to human vision, it was proven that dogs live in a colorless world dogs can see color.
How does Rover see? Dogs can definitely see colors but what they have is known as dichromatic vision. You and your pet may live in the same house and have the same environment but the difference in vision makes you and your pet basically live in a different world. Humans have trichomatic vision, meaning Rovers human friend can see the whole visual spectrum. While humans can see all the colors of the rainbow, the dogs dichromatic vision has a limited range. This kind of vision allows the dog to see only yellow and blue as well as shades of grey.
Canine and human eyes have cone photoreceptor cells. These special cells have the job of catching the light as well as recognizing different parts of the color spectrum. The pigments these cone cells contain basically controls color perception. The colors in a dogs world are less intense because while humans have three cone types, dogs only have two. The three cones in humans eyes allow 100% combined activity in the central part of the retina, therefore giving humans full range color vision. The two cone types canines have will only yield about 20% activity so that color as seen by the dog will be about 6 times less detailed. Additionally, canine eye does not have the fovea that is present in human eyes. Fovea is an area in the eye that is abundant in detail sensing cells.
Dogs may have inferior vision as far as colors go. However, dogs have the ability to see the subtle difference in the shades of color. Rover can see the different shades of blue and violet, a feat that overwhelms humans. Dogs do not have the yellow pigmentation in humans eyes that blocks wavelengths and reduces the ability of to see violet and blue lights in detail.
Rover may be color blind but the other senses more than makes up for this inability. A dog had ultra sensitive sense of hearing. The slightest sound of a burglar will certainly be heard by the dog. A dogs heightened scenting ability is a very valuable asset as well. The pet may not be happy with its new red ball but who are we to complain when the dogs excellent night vision cannot be faulted, when the dogs vigilance during dark moonless nights allows us to sleep soundly in our beds?