Since you’re reading this article, I’m guessing you’re wondering if dogs are indeed colour blind? Rest assured, you are just one of the countless people who ask the very same thing, together with “what colours can dogs see”.
There have been plenty of myths and misconceptions surrounding animals and colour vision, and our dogs have been the centre of much of this – probably because we spend so much time with them and often wonder what it’s like to see the world through their eyes.
It’s certainly an interesting subject to talk about. Here’s what we know about dogs colour blind.
How Does Colour Vision Work?
Humans and animals perceive colour through the use of light receptors, which are situated in the backs of the eyes. These receptors are in the form of cone cells, or simply, cones.
Humans have three cone types that individually allow for the processing of blue, green, and red. Meanwhile, dogs only have two cone receptor types, which individually allow for the processing of yellow and blue.
So, how do these cones allow for colour vision? When light shines onto an object, the objects in question will absorb some of the light that has hit it.
The rest of the light will then be reflected back at specific wavelengths. Wavelengths, as well as the amount of light absorbed and reflected, are dependent on the properties of an object.
Those wavelengths then reach the eyes and are interpreted by the cones, which project a fully coloured image for us to see.
Having three types of cones in the eyes which all work properly is known as trichromacy.
Individuals with colour blindness have one or two types of cone receptors that don’t work, which impairs their colour vision and prevents them from being able to interpret certain colours.
For example, the most common form of human colour blindness is deuteranomaly, which refers to faulty green cone receptors and therefore causes a decreased sensitivity to green light.
Are Dogs Colour Blind?
The short answer is no. Why the answer specifically is no, however, takes a little explaining to get to the bottom of.
Colour blindness is a condition that affects the vision and involves faulty cone light receptors in the eyes.
Most dogs, although they have fewer cones than humans, have perfectly functioning cones and are, therefore, by definition, not colour blind. Basically, where humans have trichromacy, dogs have dichromacy.
However, if what you are asking is whether dogs see colours differently and in fewer shades than humans, the answer would definitely be yes.
With fewer types of cones, dogs are unable to appreciate a lot of the tones and shades that humans can.
It’s a very common misconception that dogs can’t see any colours at all, and this is far from true.
Even in humans, complete colour blindness is extremely rare, and dogs are perfectly capable of perceiving and processing certain colours that their cones are able to interpret.
What Colours Can Dogs See?
The only way to know this answer for sure is for science to advance to the point where we can accurately see through the eyes of a dog.
Until then, though, research has made some telling discoveries that give us insight into what dogs can and can’t see.
Originally, Dr Jay Neitz, a clinical ophthalmologist with the University of California in Santa Barbara conducted research in 1989 that suggested dogs mostly saw in the shades of blue, yellow and grey.
This was an inference made based on the fact that dogs only have blue and yellow cone receptors, and several tests conducted during Dr Neitz’s research supported that.
However, many other experts disagreed with this theory and Dr Neitz’s findings, stating that dogs who seemed to recognize blue and yellow shades were responding to the different brightnesses of the colours, not the actual colours themselves.
Basically, they posited that dogs were seeing things like light grey and dark grey, not blue and yellow, and many even suggested that colour was completely irrelevant to a dog’s daily life.
Then, a team comprised of scientists from the Laboratory of Sensory Processing in the Institute for Information Transmission Problems of the Russian Academy of Sciences decided to put this idea to the test and settle the age-old debate.
They gathered dogs to participate in their research project and trained them to associate food rewards with four pieces of coloured paper, each coloured differently: light blue, dark blue, light yellow and dark yellow.
Once the dogs learned to expect rewards when these colours were shown, the scientists introduced equally sized pieces of paper with different light and dark colours on them.
A large majority of the trained pups still went for the colours they had been shown before and learned to expect rewards from, meaning they could, in fact, differentiate individual colours, not just brightness.
We still don’t know for absolute certain what colours dogs can and cannot see, but it’s a pretty safe guess that they can discern blue and yellow tones, and it’s also likely that they can also tell colours with different brightnesses apart.
So, don’t worry – your dog has a perfectly suitable colour vision for their own needs, and aren’t seeing the world in drab shades of grey! I hope this post answered your question.