Dogs are known for their keen sense of smell and ability to perceive human emotions and energy, but what about their eyes? You may have heard that dogs don’t see colour in the full spectrum that humans do, and this is correct, but it’s not all there is to the story. Below we cover how dogs see and perceive colour and some other fun facts about canine sight.
Can Dogs See Colour?
The short answer is, yes, dogs can see colours. They aren’t limited to a world of shades of black, white and gray. But they don’t see colour exactly the way humans do. Dogs are limited to mostly being able to see blue, yellow and shades of gray and are generally believed not to be able to distinguish the colours that are green or red.
This is due to the different eye structure that dogs have when compared to humans. All light is processed through the eye in the retina. The retina has cells that are called rods and cones, and these are photoreceptors, which are responsible for being able to see colour. In humans, there are three types of cones, but in dogs, there are only two. This limits the range of colours dogs can see.
Can Dogs See at Night?
The differences in how your dog sees things and how you see them isn’t limited to colour, either. Because of the evolutionary differences between dogs and humans, their eyes have also evolved differently to best meet their needs. For example, humans are what is called diurnal, which means they spend most of their waking hours in the day when it is light outside. Dogs, on the other hand, are crepuscular, which means that they are most active during the hours of dawn and dusk, when light levels are low.
What does this mean for how your dog sees? It means he can see a lot better than you can at night and in low-light conditions. Your dog has more rods in his eyes than you do, and it’s rods that are mostly responsible for detecting movement. Rods also pick up visual signals at lower light levels than cones. Biologically, having more rods and being able to detect motion in low light meant that wild dogs were better able to track and hunt prey at night.
What Is a Dog’s Range of Vision?
Colour differences aside, if you and your dog are looking at the same view in your backyard, you might be surprised that what the two of you are seeing is actually quite different. One main difference is that your dog has a lot wider point of view due to his peripheral vision.
Humans have around 180 degrees of peripheral vision, but dogs can see up to 240 degrees around them, which is very close to a panoramic view. The reason for this is that while their eyes are set to face the front — as all predators are — their eyes are usually spaced wider apart than humans relative to their head size, which gives them a greater range of peripheral vision.
When it comes to how far in the distance your dog can see, humans win. Dogs are believed to have 20/75 vision, which means that something a human with 20/20 vision could see from 75 feet away, your dog would have to be 20 feet from to see. When it comes to distance, dogs rely much more on their sense of hearing and smell to locate objects.
Can Dogs Watch TV?
If you’ve ever watched TV while cuddling with your dog on the couch, you’ve probably wondered if your dog can actually see what’s on the TV and understand what’s going on while he’s staring. While we can’t know if your dog enjoys watching your favourite shows for the plot and character development, we do have some insight into what he sees when he’s looking at the screen.
Your dog can see what’s on the screen, except for the red and green colours, but whether or not they see it smoothly depends on the flicker rate of your television set. Humans only need a minimum of 60 frames per second to be able to see the TV as a smooth image, but for dogs, the minimum is 70 frames per second. This means that while older TV sets might not keep your dog’s attention, newer sets with higher frame rates per second and better resolution might just turn your dog into your best binge-watching buddy.
Do Some Dogs See Better Than Others?
It turns out that one category of dogs, aptly called sighthounds, can see much better than other breeds of dogs. These dogs were bred over many generations to hunt by sight instead of by scent, which is how most other dogs hunt. And this has given them several biological advantages.
Sighthounds have a field of vision that can range up to 270 degrees, a full 90 degrees farther than humans. Their visual streak is also longer. The visual streak is a part of the retina where there are a lot of cones all in one horizontal area. Sighthounds have longer noses, which also means they have longer visual streaks, and therefore better vision.
So who has the better vision? Between humans and dogs, it turns out it’s somewhat of a tie. Humans can see more colours and can see farther away, but dogs are better at seeing in low light, are better at detecting motion and have much larger fields of vision.