Dogs are color blind how to see the traffic lights Dogs will see the traffic lights to cross the road

The world in a dog’s eyes is not only black and white but also colored. The dog’s retina has two types of colored photoreceptors, or cone cells, that can distinguish between short wavelengths and medium and long wavelengths of light, or shades of blue (short wavelengths) and red and yellow (long wavelengths). Because dogs have only two types of cone cells, the colors that dogs can distinguish are no different from those of red-green-blind humans. But dogs can indeed see certain colors. Dogs can distinguish between shades of blue, indigo and violet, but have no special perception of high-color colors such as red and green in the spectrum. One of the methods is to shoot a colored light source into the eyes of puppies and analyze the spectrum or pattern of reflected light, and then compare the results with the same light source into the eyes of humans to do the analysis. Red for dogs is dark, while green for dogs is white, so the green lawn in the dog’s view is a white grass. Dogs are very sensitive to changes in grayscale Dogs are very discriminating in the intensity of gray, relying on this ability to distinguish between light and dark changes on objects, producing a three-dimensional visual image. The dog’s eyesight is not good, its eye crystal body is twice as thick as that of humans, so the dog is nearsighted. Its eye adjustment ability is only 1/5-1/3 of the human. within 50 meters can see clearly, more than this distance will not be able to see. However, a moving target can be perceived at a distance of 825 meters. The guide dog relies on what to identify changes in red and green lights and the blind dog does not distinguish red and green lights by way of identifying red and green light, but relies on the brightness of the two lights to distinguish, although, red and green light in their eyes are gray, but different gray can be distinguished, the dog’s ability to discriminate subtle changes in the intensity of gray is very strong, relying on this ability, relying on this ability, it can distinguish the light and dark changes in objects, and produce a three-dimensional visual image. Dogs have a very special kind of cells in their eyes, because of which they are still able to distinguish the absorption of colors according to different spectra. This sounds a bit roundabout, simply put, different colors in the eyes of the dog, is not no difference, but the difference is not in the color, but in the brightness. These colors, will be translated into shades of brightness, feedback to the dog’s brain. That is, in the dog’s eyes, the brightness of the red light and the green light is not the same! By the difference in brightness between the two colors, dogs can easily distinguish between red and green lights.