Dogs see the world quite differently from humans due to differences in their eye anatomy and retinal structure.
Visual Acuity and Focus
- Dogs generally have poorer visual acuity than humans, often described as 20/75 vision. This means a dog must be 20 feet away to see an object as clearly as a human can at 75 feet
- They are considered near-sighted, so distant objects appear blurry to them
- Objects very close to their face (less than 10-18 inches) also appear blurry to dogs
Motion Detection and Night Vision
- Dogs have more rods in their retinas than humans, which makes them highly sensitive to movement and allows them to see moving objects much better than stationary ones, with 10-20 times greater motion sensitivity than humans
- Their rod-dominated retinas also enable superior night vision. They possess a tapetum lucidum, a reflective layer behind the retina that enhances their ability to see in low light by reflecting light back onto the photoreceptors, making their eyes appear to glow in the dark
Color Perception
- Dogs have dichromatic vision, meaning they see primarily in shades of blue and yellow. They cannot distinguish colors like red, orange, and green, which appear as shades of gray or brown to them
- This color limitation is due to having fewer cone cells in their retinas compared to humans, who have trichromatic vision (three color receptors)
Field of View and Depth Perception
- Dogs’ eyes are positioned at about a 20-degree angle on their heads, giving them a wider field of view and better peripheral vision than humans
- However, this wider spacing reduces binocular vision overlap, which means dogs have less depth perception compared to humans. Their best depth perception occurs when looking straight ahead, though their nose can interfere with this view
- Their field of view can range from about 220 to 290 degrees depending on the breed and eye placement
Summary
- Dogs see fewer colors (mostly blues and yellows) and less detail than humans.
- They excel at detecting motion and seeing in dim light.
- Their vision is blurrier at both far and very close distances.
- They have a wider peripheral vision but reduced depth perception compared to humans.
This unique visual system suits dogs well for detecting movement and navigating in low light, aligning with their evolutionary needs as predators and companions
