Are Dogs All Nearsighted?

1 The Truth About Dog Vision

We tend to think dogs see better than us — they spot us from far away and come running, and guide dogs dodge road hazards. But it is not so.

A dog’s vision is only one-fifth to one-third of a human’s, because its eye lens is about twice as thick as ours.

Dogs are nearsighted.

2 Daytime Vision

When still, a dog sees objects only within about 50 meters, and even up close it approaches by smell, with focusing ability about a fifth of ours. But for a moving target, a dog’s eyesight reaches 1000 meters — its far-sight for motion far outdoes ours. And though its focus is weak, its field of view spans 200–250° against our 180°. Not bad, right?

3 Night Vision

In the dark, a dog’s vision is far better than by day. The retina’s rod cells aid low-light sight and catch movement. Cone cells handle color and fine detail. Dogs also have an extra choroid layer, the tapetum lucidum, that reflects strongly and boosts night vision.

Light entering the eye hits the photoreceptors but can miss and pass through the retina; in dogs, the tapetum bounces it back onto the retina for a ‘second sight.’ That same layer is why a dog’s eyes glow yellow, green, or red in bright light.

4 A World of Grays

Dogs tell brightness mainly by how light or dark a color is, not by hue. They can see different shades of gray and some colors, such as blue and purple.

Dogs are also largely color-blind — they cannot tell red from green. To a dog, red is a dark tone and a green lawn looks like a white blur, so when a dog chases across green grass, it sees a vast white prairie.

5 Protecting Your Dog’s Eyes

Now that you know how poor a dog’s sight is, guard those eyes carefully — they really cannot afford damage.

1. Use a non-irritating dog shampoo. If any gets in the eyes, rinse at once with warm water and clear stray bits or discharge with a cotton swab. If the eye reddens, stop the dog from pawing it and clean with veterinary eye drops; if it looks serious, go to the clinic.

2. Do not hit the eyes with strong light — bright light damages the retina and invites eye disease like glaucoma, so keep the diet nourishing day to day.

3. Let the dog rest during exercise and keep it away from sharp hazards; a careless poke can cause retinal detachment or worse.

A dog’s world is only black, white, and gray — very plain, and the only color in it is you. Treasure and care for your dog, because its whole life holds just one person: you.