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For a long time, people believed dogs could only see in black and white. But our four-legged friends can in fact distinguish colours. In this article, you’ll find out which colours they can see, how well dogs’ eyes work in the dark, and how their eyesight differs from ours.
The ancestors of our dogs descended from the wolf and lived as hunters. They often went hunting at dusk in search of prey. To be successful, they needed to see well in the dark and required a wide field of vision so that no movement escaped their notice. Excellent colour perception and sharp vision, on the other hand, played hardly any role.
How Is a Dog’s Eye Structured?
Dogs’ eyes are structured in exactly the same way as human eyes:
The outer layer of the eye gives the eye its shape. It consists of the white sclera and the transparent cornea, which sits directly in front of the pupil. The curvature of the cornea influences, among other things, how sharply a dog can see.
The middle layer of the eye (uvea) consists of the iris, the ciliary body and the choroid. The iris gives the dog its eye colour and narrows or widens the pupil to regulate how much light enters the eye. The ciliary body is connected to the lens and also produces the aqueous humour, which regulates pressure inside the eye. Together with the choroid, it supplies certain tissues with important nutrients.
Behind the vitreous body lies the retina. It consists of many layers of cells. Its different cell types, such as rods and cones, enable it to perceive light and colour. Every stimulus travels via the optic nerve to the brain, where it is perceived as colour or brightness, allowing the dog to see.
What Can Dogs See Better Than Humans and Vice Versa?
Although human and dog eyes are structured in the same way, there are some differences in vision. Dogs have more rods than humans and a larger pupil, which means they can see well even in low light. Humans, on the other hand, have three types of cone cells, while dogs have only two. That is why dogs’ colour vision is limited.
How Wide Is a Dog’s Field of Vision?
When it comes to field of vision, dogs come out on top: while the human field of vision covers around 180 degrees, dogs can see approximately 240 to 270 degrees, depending on the breed. One reason for this is that dogs’ eyes are positioned more to the sides of their heads. However, this means the area in which dogs can see with both eyes at the same time is smaller than in humans. That is why owners are superior when it comes to 3D perception.
How Do Dogs See Their Surroundings?
In general, dogs see their surroundings less sharply and in less detail than humans do. However, eyesight is less important for dogs than it is for people. Our four-legged companions rely more heavily on other senses, such as their sense of smell, to explore their surroundings. But what exactly do dogs perceive with their eyes?
Can Dogs See Colours?
In the past, it was assumed that dogs could only see in black and white. Today, we know they are able to perceive colours. However, dogs have a smaller colour spectrum than humans.
The roughly six million cone cells in the human eye perceive colours trichromatically – meaning we can distinguish the primary colours red, blue and green, as well as mixed colours such as orange and turquoise. Dogs’ eyes, like cats’ eyes, are dichromatic: their ability to perceive red and green is weaker.
Which Colour Can Dogs See Best?
Dogs can easily distinguish between blue and yellow and see these colours best. While humans can see purple because our cone cells are specialised for red and blue, dogs perceive purple as blue.
Because dogs only see colours weakly, they orient themselves by the brightness of objects. Numerous rods in the retina help them do this: these light-sensitive sensory cells are responsible for detecting differences between light and dark.
Good to know: Guide dogs do not see whether a traffic light is red or green – instead, they react to the brightness of the light.
How Well Can Dogs See in the Dark?
As hunters that were originally active at dawn and dusk, dogs have good night vision, provided it is not completely dark. This is due partly to the rods in the retina. Another important factor is the crescent-shaped tapetum lucidum (Latin for “shining carpet”).
These crystal-like structures located in the choroid reflect incoming light back into the eye, which stimulates the sensory cells more intensely. This phenomenon can be observed when car headlights shine into the eyes of wild animals at the roadside at night. In dogs, the tapetum lucidum appears as a yellowish to blue-green shimmer.
Dogs can see well even in the dark. This is due to crystal-like structures in their eyes that can reflect light. Their eyes then appear to glow.
Are Dogs Short-Sighted?
Many dogs are slightly short-sighted. Above all, they see less clearly than their owners. This is because their eyes cannot focus as well and their corneas are more curved than those of humans.
How Do Dogs Perceive Movement?
Rather than being geared towards sharpness, fine details and colours, dogs’ vision is adapted for seeing in low light and detecting movement. Dogs perceive movements, such as a ball flying through the air, much faster and more smoothly than humans do.
The rods in the eye are responsible for this: they determine how quickly dogs can perceive changes in light and at what point many rapid changes between light and dark no longer appear as flickering but as a steady, blurred image. This flicker fusion frequency is around ten to 60 stimuli per second in humans, while in dogs it is around 80.
A recent study supports the fact that dogs focus on action: using MRI scans, researchers discovered that dogs concentrate on what is happening, while humans tend to focus more on objects. Dogs’ brains therefore process movement more strongly than objects. This explains why dogs can easily overlook a toy if it is not moving.
How to Take Your Four-Legged Friend’s Eyesight into Account in Everyday Life
When playing, it is better to choose blue toys rather than red ones. If you are out in the park and call your dog to you from a distance, wave to them so they can not only find you through their sense of smell but also visually recognise where to go.
You can find blue and yellow toys for your four-legged friend in the zooplus shop:
Common Eye Diseases in Dogs
Compared to hearing and smell, a dog’s eyes are less powerful. Even so, it is important to look after your dog’s eye health. Red eyes or suddenly reduced vision are clear signs that your dog may be suffering from an eye disease and that you should visit your vet.
The following eye diseases are particularly common in dogs:
glaucoma caused by damage to the optic nerve due to increased pressure inside the eye
cataracts caused by pathological clouding of the lens
sometimes painful inflammation inside the eye (uveitis)
enlargement and prolapse of the third eyelid gland (cherry eye)
Important Note: The content provided for informational purposes only and is not intended to replace professional veterinary advice, diagnosis or treatment. If you have any questions or concerns about your pet's health, please always consult a licensed veterinarian.
This article was translated using Artificial Intelligence from the original German zooplus Magazine. While the original content was authored by industry experts and reviewed by our editorial team, this automated translation has not been human-edited and is provided for informational purposes.
At the Justus-Liebig-University of Giessen I was extensively trained as a veterinarian and was able to gain experience in various fields such as small animal, large animal and exotic animal medicine as well as pharmacology, pathology and food hygiene.
Since then, I have been working not only as a veterinary author, but also on my scientifically driven dissertation. My goal is to better protect animals from pathogenic bacterial organisms in the future.
Besides my veterinary knowledge, I also share my own experiences as a happy dog owner and can thus understand and enlighten fears and problems as well as other important questions about animal health.
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