Do Dogs See in Color?
Dogs are man's best friend, but they are not all alike. Unlike humans, dogs do not see in the broad spectrum of the rainbow we know. When I first heard that dogs only see black and white, I did not believe it, so I researched a little bit to find out exactly what was true.
First, I started with the eyes and how seeing color actually works. The inner workings of the eye are interesting. The retina is the deepest inside the eye and its job is to sense light and send the information visually to the brain. There are photoreceptor cells inside of the retina(What do Dogs See? A review of Vision in Dogs, 1996). These two photoreceptors are rods and cones, and they respond to light and send signals to the optic nerve(What do Dogs See? A review of Vision in Dogs, 1996). . This happens through a series of chemical processes and reactions. Rods handle light strength and weakness, and cones absorb the information concerning color and details(What do Dogs See? A review of Vision in Dogs, 1996).
The photoreceptors, known as cones, perceive precise wavelengths of colors(What do Dogs See? A review of Vision in Dogs, 1996). . Humans have three types of cone cells in their eyes and we perceive specific portions of the color spectrum(What do Dogs See? A review of Vision in Dogs, 1996). . The three cones we have in our eyes allow us to recognize colors that vary in mixtures of red, green, and blue pigments. Dogs are different from humans because they only have two cones in their eyes, and they have less rods and cones than humans do(What do Dogs See? A review of Vision in Dogs, 1996). Because of the differing cone and rod structure of a dog's retina dogs see a spectrum of yellow, blue, and gray, instead of the rainbow that humans see(What do Dogs See? A review of Vision in Dogs, 1996). Dog's have only two cones, and this removes their ability to recognize reds, and green.
So the main reason dogs see differently is because they so not have as many cones and rods as humans do at all. Dogs do have certain visual characteristics that we do not have. Dogs may not be able to see rainbows of color, but they can see extremely better in the dark than humans can. Dog's have a receptive structure behind their retina that makes their night vision extremely improved(What do Dogs See? A review of Vision in Dogs, 1996). This reflective structure makes dog see things in the dark as if they have an interesting glow (What do Dogs See? A review of Vision in Dogs, 1996).
It turns out that dogs see in black and white but also some yellows and blues. Unlike humans dogs can see very well at night time and have a different eye structure than humans. Man and dog may have many differences, but man and dog will always be best friends!
References:
What do Dogs See? A review of Vision in Dogs. (1996). . Retrieved October 7, 2007, from http://psychlops.psy.uconn.edu/eric/class/dogvision.html