Dogs are not color-blind are color-weak dogs are not color-blind, just weak in color discrimination, humans have three types of visual cone cells that allow us to see all the colors in the spectrum. Dogs, on the other hand, have only two types of cone cells and can only better distinguish black, white, gray, blue, purple, etc., but cannot recognize red, green, etc. Guide dogs, on the other hand, distinguish colors based on how bright they are. Plus dogs are nearsighted, about 150 degrees if converted to degrees, which means that a dog’s vision is about 1/5 to 1/3 of a normal human. Some people will feel very poor, but the dog is only 150 degrees of nearsightedness, some shovelers are much higher than this degree of nearsightedness.
