Dogs primarily rely on their noses to navigate the world-smell is their most important sense. Dogs do not rely on their eyes like humans do which is why blind dogs or dogs with diminished sight can lead lives of quality. A blind dog can adapt readily to its environment as long as there are not too many changes.
Even though eyesight is less important to dogs than people, there are many interesting facts about the dog’s eye.
- Dog eyes are more widely spaced than human eyes and are directed outwards. This gives them increased peripheral vision. A dog can see 250-270 degrees as compared to 180 degrees in people. Unfortunately, dogs do not have as good depth perception as we do due to less overlap in the visual field.
- Third eyelids – this eyelid protects the cornea and washes away debris. It also contains a gland that helps supply tears. This eyelid is not always visible and tends to be the most prominent during sleep or when they are outside in the wind and dust.
- Color – dogs have rods and cones in their retina just like people however they have more rods and fewer cones. The decreased amount of cones in the dog eye result in a decreased ability to perceive fine detail and colour. Dogs have only two types of cones which are sensitive to yellow and blue. This results in similar colour perception as a person who has red/green colour blindness. Dogs see the world in varying shades of yellow, blue and violet-an orange ball will look yellow on yellow grass.
- Have you ever noticed your dog’s eyes shining in photographs? This is due to tissue behind the retina called the tapetum lucidum, which rebounds light like a mirror. This tissue helps dogs have superior low light/night vision as compared to people.
- Dogs have an increased ability to perceive motion due to more rods in their retinas than humans. Dogs can see 80 images per second compared to humans 60 images per second.
Written by Cumberland Veterinary Clinic