Why is an eagles vision so good?
Because they are birds.
depends on your definition of "good" cats have excellent night vision and motion Sensitivity. But overall vision (resolution) is basically determined by eye/pupal size and cats are similar to ours. so to get the better night vision and motion Sensitivity they give up other areas. Cats are extremely near sighted, vision is believed to be blurry and colors washed over. bovine and horses with their larger eyes have excellent vision