Last Updated: 04/02/2026
Why Do Cats and Dogs Eyes Glow in the Dark?
Learn how a special reflective layer called the tapetum lucidum gives our pets "superpower" night vision and why different animals reflect different colours.
Author: Dr Teagan Lever BVSc (Hons)
Reading Time: 3 minutes - short read
Have you ever snapped a photo of your pet only to be greeted by a pair of glowing, supernatural-looking eyes staring back from the screen? While it might look like something out of a spooky movie, that eerie "eye shine" is actually a fascinating biological feature. This glow is a sign of a highly evolved visual system designed to help our furry companions navigate the world when the lights go out.
In this article
Seeing through the dark
You might remember from science class that the human eye contains sensory receptors called rods and cones. Cones are responsible for detecting different colours and function best in the light. The rod receptors in our eyes allow us to see in low light settings however rods cannot pick up colours. Cats and dogs have a much higher concentration of rod receptors in their eyes which allows them to see much better in the dark compared to humans.
The secret layer behind the glow
Unlike humans, cats and dogs have an additional layer of tissue in their eyes called a Tapetum Ludicum. This tissue layer sits behind the retina and reflects light back through the retina to hit the photoreceptors (rods and cones) a second time. This reflection gives the light a second chance to hit the animal's photoreceptors which in turn helps to enhance their night vision. This reflection is the "glowing" that we see when we accidentally shine a bright light on our pet in a dark environment.
Why do different animals have a different colour shine?
The mineral concentrations in the Tapetum affect the colour that is reflected back through. Depending on the levels of Zinc or Riboflavin present in the Tapetum tissue, the animal's eyes will reflect different colours from yellow or green to even violet.
When the glow turns red
It has been found that most blue eyed cats and dogs are actually lacking a tapetum membrane and in single flash photos you will notice that the "reflected" colour is red. Without the mirror like function of the tapetum, the flash is actually picking up the red colour because of the blood vessels in the eye which is what also happens to humans.
FAQs
So, there is no need to call an exorcist next time you see those glowing yellow or green orbs peering through the shadows. It is simply your pet’s incredible anatomy at work, using every available bit of light to keep an eye on things. Whether they are reflecting gold, green, or even red, it is just one more way our pets are perfectly built for their twilight adventures.
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History
Our experts continually monitor the health and wellness space and we update our articles when new information becomes available.
Wed 4 Feb 2026
Edited by Dr Gillian Hill BVSc (Hons)Dr Teagan Lever BVSc (Hons)
Head Veterinarian, BVSc (Hons)
Pet Circle's Head Veterinarian, Dr Teagan graduated from the University of Queensland in 2010 and went on to work in small animal and mixed practice in various locations around QLD & ACT before joining Pet Circle in early 2016. Dr Teagan has special interests in dermatology, nutrition and preventative health care. She feels privileged to witness the special bond people share with their pets on a daily basis and enjoys forming lasting relationships with pet parents and their fur children.
