It’s a long-held myth that dogs are all colour blind, but the way your canine friend perceives the world isn’t as simple as we do.

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While dogs certainly have a unique way of seeing the world, it’s a myth that they only perceive it in monochrome. Despite what you may have heard, dogs do in fact see colours. They simply see a different spectrum to us – one with less intensity and fewer colours.

What do dogs see?

In order to understand what dogs see, we also need to understand how it is that we see. Both humans’ and dogs’ eyes contain light receptor cells in the retina called cones, which respond to colour. While humans have three different types of cones, each tuned to different wavelengths of light, dogs only have two types of cones. This means that dogs’ brains can distinguish blue from yellow, but not red from green – similar to someone with red-green colour blindness.

In effect, when we look at a rainbow, we see violet, indigo, blue, green, yellow, orange and red, where a dog sees dark blue, light blue, grey, light yellow, browny yellow and dark grey. 

How do we know this?

In 1989 Dr. Jay Neitz, professor of ophthalmology at the University of Washington, published a paper entitled Colour vision in the dog after having experimented on three domestic dogs – two greyhounds and a toy poodle. The dogs were shown three light panels – two were the same colour, while one was different. The dogs were tasked with finding the one that was different, and if they did so correctly they were rewarded with food – a very good motivator for most of our canine friends. The results showed that dogs have ‘dichromatic colour vision’; that is, they have two types of cones.

In 2013 a group of researchers from the Laboratory of Sensory Processing at the Russian Academy of Sciences confirmed Neitz’s findings when they tested the sight of eight previously untrained dogs.

What other animals have ‘dichromatic colour vision’?

Dichromatic colour vision is quite common in mammals, it’s been discovered in all kinds of bats – even nocturnal ones like carnivorous bats, several species of squirrel, pigs and treeshrews to name but a few. 

Which animal has the most sensitive eyes?

The mantis shrimp has anywhere from 12 to 16 different types of cones and can also see in ultraviolet. 

Take home message…

Invest in a bright blue or yellow toy for your dog.