Coward said:

"Generally speaking, the vision of a bird is two to three times that of a human. If it is an eagle or other birds with better vision, the vision is more than ten times that of a human."

"Parrots have exclusive eyeballs, regardless of the size of mung beans, but it not only has good eyesight, but also can distinguish colors, shapes, and ultraviolet rays...Of course, this is also related to the parrot's brain."