Dogs are color blind guide dogs how to distinguish between red and green lights

Guide dogs see traffic lights not as a judgment of color, but rely on the brightness of the light to distinguish. This is because although dogs cannot see red and green, they are able to judge different shades of gray in their eyes. They are very discriminating in their ability to distinguish subtle changes in the intensity of gray, and with this ability, they can distinguish between light and dark changes in objects, thus producing a three-dimensional visual reflection. Among all animal categories, dogs have intermediate vision. The dog’s eye adjustment ability is only one-fifth of the human, for some fixed things, the dog can only see up to fifty meters, while for some dynamic things, the dog’s field of vision to capture the range of one thousand meters.