How do the pupils in a dog’s eyes operate to see movement and panoramic views?FamilyPet
Dogs see very differently than people, partially because they are mostly colorblind, and partially because they have a much wider field of vision. The position of an animal’s eyes on his head will determine the possible visual field. While people have strictly front facing eyes, a dog’s eyes are positioned on the sides of the head, which allows for greater peripheral vision. People can see just under 180 degrees without moving their heads. Dogs can comfortably see 240 degrees without movement.
However, this greater field of vision brings with it a setback when it comes to what dogs can see directly in front of themselves. A dog’s central field of vision is half of what people can see, which leads experts to believe that dogs are nearsighted and cannot view objects that are directly in front of them but far away. The pupil of a dog’s eye dilates in order to let in maximum light, and a reflective layer behind the dog’s retina allows for even greater sight capabilities in low light. Humans do not possess this reflective layer, so a human eye is not as sensitive to low-light environments as a dog’s.
A dog’s eyes see in a greater range of grey than humans because they do not see all of the colors that humans are able to process. A dog sees some red and blue, along with mostly black and white because of the high percentage of rods that are present in the eye. Rods detect black and white, and are also more sensitive to light than the cones that predominantly make up a human eye.