Dogs can do some pretty amazing things. They have an incredible sense of smell, can hear sounds from very far away and can even detect certain diseases. But is their sight as good as their smell and hearing? Do they also have the ability to see at night and navigate around your house or yard in the dark?
Before you leave your pup in a dark room at night, you'll want to figure out the answer to this question.
The evolutionary sight of dogs
Dogs evolved from wild canines, who were crepuscular. This meant they were active mostly during the dusk and dawn hours. They would hunt their prey at night primarily, since they were nocturnal hunters. To be able to see what they were doing, they needed to have strong vision when it was dark outside.
The anatomy of dogs’ eyes
Dogs have larger pupils than humans do, just like cats and mammals.
Dogs' eyes also contain the tapetum lucidum. The tapetum is basically a mirror in the eye that reflects back the light that passes through it. This also helps them see light. If you have taken a photo of your pup and noticed his eyes were glowing, what you're seeing is the tapetum reflecting light that your dogs' eyes are unable to absorb.
Human and dog retinas have light-sensitive cells calls rods, which allow dogs and humans to be able to see in low-light settings. Dogs have more rods than humans, however.
Since the structure of dogs' eyes are different, they can usually see much better in the dark than humans can.
Aging dogs and eye diseases
There are some exceptions to the rule: aging dogs and dogs with eye diseases. Sometimes, older dogs develop conditions like nuclear sclerosis, cataracts or a mass around the optic nerve. All of these can decrease their ability to see well, even during the day. If your senior dog is confused at night or acting particular when the lights are dim, he may have one of these conditions.
Some dog breeds are also known for having an eye disease known as progressive retinal atrophy. This condition affects the photoreceptor cells in the eyes, causing them to deteriorate overtime. Eventually, a dog can become blind from this disease, even if he is young. PRA is genetic, so it's not wise to breed a dog with the condition. The breeds that are more likely to have PRA include Cavalier King Charles Spaniels, Labrador and Golden Retrievers, Bullmastiffs, Old English Mastiffs, American Cocker Spaniels and Rottweilers.
If your dog has PRA, the first thing that you'll notice is he's having trouble seeing at night. When it gets dark outside, he may become nervous, and he may bump into things in low-lighting situations. It's not a painful disease, and even when dogs go completely blind, they can rely on their sense of smell and hearing to get around better than a blind human could.
Practicing safety in the dark
If your dog has PRA or another condition, make sure you keep his environment familiar by not moving things around. Otherwise, he could bump into furniture and other objects and potentially hurt himself.
Even if your dog has great vision, you should still carry a flashlight or install a light in your yard to protect yourself and your pup. What if you were walking and you fell, or there was a deer or coyote in your yard that you couldn't see without a light? Being aware of the dangers around you is key.
Of course, if you think your dog may be having issues with his eyes, make sure you take him to the veterinarian to get checked out as soon as possible.