Can Dogs See in the Dark?

The structure of the eye plays a big part in how dogs see at night.

Dog owners know that dogs are the best companion to have when out for a walk, on a hike, or simply enjoying quality time together at home. But when out for an evening stroll, how are dogs able to see so well? However, just like humans, pets can develop eye conditions, too. Here are 5 signs of glaucoma every dog owner should know.

The canine eye

You may have noticed from the puppy eyes your dog gives you, but dogs actually have large pupils, which helps with their vision. “The canine eye, like the eyes of cats and other mammals, has a larger pupil than a human eye, allowing more light into the eye,” Dr. Katy Nelson, senior veterinarian at Chewy, tells Reader’s Digest. “Dogs also have a much wider field of vision than humans do. A dog’s field of vision is approximately 250 degrees, as compared to that of a human estimated to be around 190 degrees.” Here’s what your dog’s facial expression really means.

Can dogs see in the dark?

The structure of the eye plays a big part in how dogs see at night. “The structure of the retina (the nerve layer that lines the back of the eye, senses light, and creates impulses that travel through the optic nerve to the brain) has light-sensitive cells, called rods, which help animals (and humans) to see in low light,” says Dr. Nelson. “While we’re not sure of an exact number, research has shown that dogs have many more of these rods than we do.” These are the 12 warning signs of cancer in dogs that every owner should know.

“The other types of cells in the retina are called cones. Cones perceive color, and function best in well-lit environments,” Dr. Nelson adds. “While the human eye has six million cones, dog eyes only have about 1.2 million cones. This means that dogs have a less acute vision in bright light than we have.” This is how dogs get humans to fall in love with them, according to science.

Can dogs see color?

The idea that dogs live in a black and white world was once widely accepted but according to the American Kennel Club, dogs can actually see in color—though that may look different from what humans see. This can be explained further using cones. “There are different types of cones that allow for the detection of different wavelengths of light, determining the ability to detect color,” says Dr. Nelson. “Humans have three different kinds of cones, while dogs only have two kinds of cones. Because of this difference, the number of colors your dog can perceive is much smaller than the wide array humans can see.” Here are 13 common “facts” about dogs that are totally false.

Can dogs be color blind?

There are three different kinds of color-blindness in humans, so it would make sense that dogs’ can similarly be color blind. “Dogs’ eyes function similarly to colorblind humans (red-green color-blindness). They mainly see blues, yellows, and grays,” says Dr. Nelson. “To a dog, an orange or red toy lying in green grass appears the same color as the grass. Dogs can better see a blue toy in green grass.” Here’s how much exercise your dog really needs to maintain a healthy lifestyle.

Why do dog’s eyes glow green in the dark?

You’ve probably noticed in your evening walks that when the light hits your dogs’ eyes a certain way, they appear green. This is due to the tapetum lucidum, a shiny surface in the back of the eye. “[The tapetum lucidu] is what glows bright green when you shine a flashlight at a dog/cat in the dark. The tapetum acts as a mirror within the eye, reflecting the light that enters it and allowing the retina another opportunity to pick it up and register the light,” says Dr. Nelson. “It also amplifies the light through a process called fluorescence. Fluorescence slightly changes the color of the light reflected back to a wavelength that is closer to what the rods in the eye are most sensitive to and can detect. The tapetum can reflect up to 130 times more light than the human eye, which is why dogs are five times more sensitive to light than we are.” Dog owners alongside scientists are learning more about dogs every day. Next, here’s scientific proof that your dog loves when you smile.

Madeline Wahl
Madeline Wahl is a Digital Associate Editor/Writer at RD.com. Previously, she worked for HuffPost and Golf Channel. Her writing has appeared on HuffPost, Red Magazine, McSweeney's, Pink Pangea, The Mighty, and Yahoo Lifestyle, among others. More of her work can be found on her website: www.madelinehwahl.com