What the dog sees the world is like

In the eyes of the dog the world is black, white and dark gray, while interspersed with medium and long light waves of red and yellow light and light waves of short blue light, the world is like the picture in black and white television, only the difference between black and white brightness, and can not distinguish the color changes. Dogs not only poor eyesight, but also not very sensitive to color, can only distinguish shades of gray, blue and purple, so the world in the eyes of dogs is almost black and white, and the distant scene is likely to be very similar to those seen by nearsighted people.