Can Your Dog Actually See Well in the Dark?
If you've ever wondered how your dog gets around so well outside for his late-night potty break, you may be surprised to learn that he can see just fine at night. No, dogs don't have night-vision goggles, but they can see better than we can in the dark.
Both humans and dogs have photoreceptors called rods and cones, and it's the rods that help animals and humans with their night vision. Cones are for daytime visual acuity. Rod receptors help with night vision, shades of gray, and tracking movement, explains Dr. Georgina Ushi Phillips, a veterinarian at Not a Bully, a site that dispels myths about misunderstood breeds.
"By analyzing the number of rods and cones in our dog's eyes and comparing them to our own, we can get a great idea of what they see—and what they don't see," says Dr. Phillips. The conclusion: Dogs have way more rods than their owners.
Do Dogs See in 20/20 in the Dark?
"Most dogs have 20/75 vision which means that they have to be at 20 feet to see what humans can see at 75 feet," says Dr. Phillips. Not bad at all. Plus, what they don't see in acuity or color since dogs have a slightly worse sense of color vision, they more than make up for with their ability to see well in low lighting. "It can be difficult to pin down an exact number, but research suggests that dogs can see in light five times dimmer than we can," says Dr. Phillips.
Why Do Dogs' Eyes Glow on Camera?
If you've ever snapped a photo of your pup with a flash camera, you may have noticed that their eyes have a wild glow, especially at night.
"That's caused by the tapetum lucidum, which helps reflect light in the eye and allows for better night vision," says Dr. Phillips. It acts like a mirror and is also something that we humans don't have.
"But what's really interesting is that the color of this glow can change from various shades and combinations—green, orange, yellow, and blue based on the breed of your dog." Called eyeshine, this luminescence can also vary with the age of your dog and his eye and coat color. Dogs with white coats and blue eyes can even give off a red glow.
So, go ahead and quickly check your smartphone to see if you have any pics of your favorite pup's eyeshine to see what color it is. Want to eliminate glowing eyes when you take your dog's picture? Snap two photos in quick succession. In the first, the flash will make their pupils smaller, so the second photo is less likely to include eyeshine.
Now you know why your dog has no trouble finding a good spot to potty in the dark.