Can animals see in colour?

Different animals can see different kinds of colour from a broad range of spectrums. Some see very little colour, while other creatures – such as bees and butterflies – see more than us as humans.

But what about your pets – how do they see the world? The answer is not as simple as you’d think, because colour does not actually exist.

What is colour?

Colour is your brain's way of processing light wavelengths. Light hits your eyes and special cells (photoreceptor cone cells) turn it into nerve impulses. These are then passed to the brain and processed into the various colours.

Human eyes also have more than 120 million rod cells that process low level light and the shape of objects, but not colour. Because some animals have different cone cells and rod cells to humans, it's incredibly difficult to test whether our animals see in the same colours that we do.

Can dogs see in colour?

There is a common misconception that dogs can only see in black and white. Dogs can, in fact, see a wide array of colours. But the range is more like that of a human who has red-green colour blindness, seeing only various shades of blue, yellow and green.

This is because humans have three cells (photoreceptor cone cells) in their eyes – blue, red and green. Dogs only have two – blue and another that falls between the human red and green cone.

These colours do not affect a dog’s sight. In fact, dogs have more rod cells in their eyes than humans, which allow for better vision in very low light.

Can dogs see in the dark?

Dogs can see in very low levels of light. They have a secret weapon, a reflective mechanism – a retroflector called the tapetum lucidum. This means that your dog’s eyes reflect the light that goes into their eyes back out, allowing a much more detailed view of the world after dark. You may also notice that your dog's eyes shine at night or in photos.

Can cats see in colour?

Unlike dogs, cats have the same amount of cone cells in their eyes as humans. But it’s thought that cats cannot detect colour as well as us. Cats are also not as well equipped at seeing objects at a long distance.

Can cats see in the dark?

Cats are crepuscular, meaning they become more active at dawn and dusk. Their vision lends itself to these times of day, because they have around six to eight times more rod cells in their eyes than humans do. This allows them to see more clearly in low light.

Just like dogs, cats have something called tapetum lucidum. This gives them that eerie eye glow in the dark. This is because they absorb the light that is available and their eyes reflect this back out which increases their ability to see well in low light.

Can horses see in colour?

Horses, like dogs, have two cone photoreceptor cells in their eyes. This is otherwise known as dichromatic vision. Research suggests that horses have blue and green cone cells and struggle to see red because of this.

Experts believe that horses see the world in less saturated colours than humans. But it’s hard to know for sure, because colour is processed within the brain after being fed information from the eye.

A horse sees in less detail than we do, but has a much broader field of vision.

How does your pet's eye position affect their vision?

The height of your pet plays a big role in the way that they perceive the world around them. As an example, a small dog (such as a terrier) would find tall grass hard to navigate and would see it as a wall of grass with no clear route through. Whereas a border collie placed in the same position as the terrier would be able to clearly see the way through. This can make a big difference to the way you should train and introduce your dog to new situations.

Your dog’s eye position on their head can also affect the way that they see the world. As an example, brachycephalic breeds such as pugs have less forward facing eyes than other breeds, which means that their field of view is slightly different to that of other dogs.

Dogs, on average, are estimated to be able to see 240 degrees around them which is far greater than humans who have a field of view of 180 degrees. This greater peripheral vision is linked to the natural hunting behaviours their ancestors would have in the wild.

Horses, meanwhile, have a big field of vision. This is because horses are prey animals. It's important to their survival that they can pick up movement from more angles, so that they can act quickly to escape predators.