Are color-blind dog. Scientists can use two methods to determine this point. However, here or let us first take a look at the dog's eyes in our universe is what kind of bar.
The dog there are two types of retinal cone cells, they can identify the short-wavelength and long wavelength light, which is able to feel the ray (wave length of light waves) and the yellow light (medium-and long-wavelength light waves). Cone because of small reasons, dog eyes of the world's color is very monotone, unlike human eyes of the world as colorful. However, there are three types of human cone cells, we can see all of the visible spectrum of light colors.
The same color, then the same whether the dog can see these colors do? Scientists in order to determine this point has taken two ways.
One approach is to use light beam irradiation has a dog's eyes, this will be a reflection from the eyes of dog images, the scientists of the reflectivity images of the study; after then it was the eyes of the same type of light reflecting image contrast.
Another method is to train a dog can "tell" scientists see their world. In the experiment, scientists look for dogs color several groups, each have three each color, of which two are the same. In addition to give a very small amount of training, the dog will use his nose to the scientists pointed out that in each group different colors of light. Scientists need only changing the color of light to repeat this process, we can conclude that: In the eyes of the dog world is black. White and dark gray, while medium-and long-wave mixed with the red and yellow light and blue light waves short, the world as black and white television screen, only black acetabular different brightness, and unable to discern color changes. Seeing eye dog is able to distinguish between red and green lights, two lights are to rely on the distinction between brightness. Dogs on the gray shades of discernment is very subtle, to rely on this ability, we can distinguish objects on the light changes, resulting in a three-dimensional visual image.
