Why are dogs color blind? This point must be clarified

Dogs are not color blind but color weak

Dogs are not color blind, but their ability to distinguish colors is relatively weak. Humans have three types of cone cells, which allow us to see all colors in the spectrum. Dogs only have two types of cones, which can only distinguish black, white, gray, blue, purple, etc. well, but cannot distinguish red, green, etc. Guide dogs distinguish colors based on their brightness. In addition, dogs are myopic. If converted into degrees, it is about 150 degrees, which means that dogs’ vision is about 1/5 to 1/3 of normal people. Some people may find it pitiful, but dogs’ myopia is only 150 degrees, while some people’s myopia is much higher than this.