If you’ve ever snapped a picture at night of your dog, only to see a creepy haunting shine emanating from their peepers, you may wonder, “why do my dog’s eyes glow?” What’s more, some dogs have a yellow or orange shine looming out of the darkness.
Others have a blue, green, or red glow if you shine a flashlight on them in the dark. In some cases, one eye is glowing and the other not. Let’s look at why dogs’ eyes glow in the dark and why some dogs’ eyes glow in different colors from others.
Why Do My Dog’s Eyes Glow In The Dark?
Dogs’ eyes glow in the dark because they are carnivores and their eyes reflect light to give them better night vision for hunting. Their eyes have evolved a reflective surface behind the retina and in front of the optic nerve called the tapetum lucidum. It reflects incoming light back to the retina so that light-sensitive cones and rods have a second chance to pick it up. This is a nifty way to “recycle” or make the most of light in the dark.
So just like a mirror, if you shine a light in your dog’s eyes, it will reflect back at you. This is just one way that the canine vision differs from ours. They also have bigger eyes that can collect more light and rods, which are light-sensitive cells. On the other hand, they have fewer cones than us, meaning they can see fewer colors.
And they even have a third eyelid, called the nictitating membrane. Because of all these intricacies, keeping our dog’s eyes clean should be part of our daily routine, and recommend natural dog eye wipes to wipe away any discharge or debris to prevent infection.
If you want to read more about a dog’s nictitating membrane, you can see our article on dog eyelids.
In general, creatures active during the day, such as us, primates, pigs, squirrels, and even kangaroos, do not have the tapetum lucidum. Other animals have evolved very different tapetum surfaces. For example, a crocodile has a retinal tapetum, while carnivores like dogs and cats have choroidal tapetum cellulosum.
The fact that carnivores generally have glowing eyes may be one of the reasons we find eye shine so spooky and eery. Deep down, humans probably know that glowing eyes in the dark can mean danger.
What Color Should My Dog’s Eyes Glow?
Surprisingly, there is no specific color that a dog’s eye should glow. They glow shades of white, yellow, orange, or red. Many dogs also have a green, blue, purple, or turquoise glow. The same dog may even have one eye glow red, one blue, or another color. We will discuss this below.
You may have noticed different color glows if you’ve ever taken a photo of multiple dogs at once. This is another fascinating aspect of eye shine since factors like a dog’s breed, coat color, and eye color can influence the color of the shine.
Why Do Dog’s Eyes Glow Different Colors?
The color of the eye’s reflective glow depends a lot on the individual ocular chemistry of the dog, so there can be changes in hue even within the same breed.
This is because the tapetum is reflective. After all, its cells contain between 11 and 15 layers of cells with the metal chelate, zinc cysteine. Zinc cysteine acts as the metallic mirror. Each dog has different amounts and ratios of these reflective compounds in the tapetum, causing different color glows.
Remember that this is not the same as a cat’s eyes, where the reflective material is riboflavin or a mix of riboflavin and zinc.
This is one of the reasons for making sure dogs get enough zinc and sulfur-bearing amino acids in their diet. These include methionine, cysteine, and taurine. If you want to read more about maintaining your dog’s eye health, read our article on taking care of dog’s eyes.
Why Do My Dog’s Eyes Glow Red?
If dogs do not have the reflective tapetum, like humans, the light from a camera flash reflects off the blood vessels in the retina, causing a red glow in pictures. This is most common in dogs with white fur or blue eyes. You will also often see it in Siberian Huskies. In one Swedish study, about 1.9% of dogs had no tapetum.
If your dog has noticeably red eyes during the day, they may have conjunctivitis or pink eye.
Why Do Dog’s Eyes Glow Yellow or Orange?
The English Springer Spaniel and Bernese Mountain Dogs typically have an orange glow at night. Meanwhile, the yellow Labrador (and sometimes the black or chocolate Lab) and the Border Collie may have a yellowish light. However, there is no hard and fast rule, as it can still differ from dog to dog with the breed.
Irish Setters are also known for a reddish or orange glow in pictures.
Why Do My Dog’s Eyes Glow Green Or Blue?
Green is one of the most common eye colors that dog eyes glow at night. You should see this in German Shepherds and many others. It is likely a sign of more layers of reflective zinc cysteine in the tapetum.
Fewer dogs, most notably the Schnauzer, will have eyes that glow a gorgeous blue or soft turquoise. This seems to be due to something genetically different in the chemistry of their eyes.
Why Does Only One of My Dogs’ Eyes Glow?
Occasionally, a dog will have one eye that glows the more common green or blue and another that does not glow or glows red. This is called tapetal hypoplasia and is a hereditary condition where the dog is missing the tapetum from one eye.
It can sometimes happen in dogs with heterochromia, where a dog has two different colored eyes, common in Australian Shepherds or Huskies. The blue eye may lack a tapetum in these cases.
Why Do Dogs’ Eyes Glow in Pictures?
If you take a shot at night, the dog’s eyes will usually glow in pictures and photos. This is because the flash is quite close to the lens; if you take a photo, the light should hit the tapetum and reflect back.
Their pupils are also more dilated in the dark, so the sudden flash of light reflects against a much larger surface.
How to avoid glowing eyes if you are taking photos of your dog in low-light conditions
If you are on the same level as your dog and looking directly into their gaze, the eyeshine will also be worse. If you want to avoid the nightmarish ghostly glow, then photographer Frikkie Kapp advises:
- Ask someone to distract your dog so that they angle their gaze away from you. It helps if they look over you, or to the side, away from you. If their eyes are not directly facing you, they are less likely to cause a reflection.
- Don’t use a camera with a built-in flash close to the lens. Use a tilt-head flash to bounce light up at the ceiling, not directly into your dog’s face.
- If you can’t improve the light in the environment, use the flash twice to get the pupils to constrict. Then quickly take the photo before they dilate again.
- Put wax paper over your lens to diffuse the light from the flash so that it is not so harsh.
Dogs’ eyes glow because of a brilliant little structure called the tapetum lucidum that reflects incoming light across the rods and cones of the eye. This allows the eye to make the most of any light in dim or dark conditions.
Not all dogs have this, however, which means that some dog eyes will have red eyes in photos as the light will reflect against their blood vessels rather than the tapetum. But for other dogs, a picture from a direct flash should show a green, orange, or bluish glow.
Tamsin De La HarpeAuthor
Tamsin de la Harpe has nearly two decades of experience with dogs in rescue, training, and behavior modification with fearful and aggressive dogs. She has worked closely with veterinarians and various kennels, building up extensive medical knowledge and an understanding of canine health and physiology. She also spent two years in the animal sciences as a canine nutrition researcher, focusing on longevity and holistic healthcare for our four-legged companions.
Tamsin currently keeps a busy homestead with an assortment of rescue dogs and three Bullmastiffs.