What Colours Can Dogs See?
Many people are under the misconception that dogs are colour blind and can only see things in black, white and grey, therefore making them wholly different to their masters. However, the notion that dogs are colour blind is not completely accurate as research has shown that dogs can see several different hues and shades of colour, although the way they perceive colour differs to the way humans perceive it.
Why do people think dogs are colour blind?
The founder of National Dog Week, Will Judy, is believed to have first pitched the idea that dogs are colour blind in the 1930’s. Little is known as to why he stated this fact which is now known to be untrue, however he maintained that dogs had poor vision and could only see the outline of shapes and objects.
What colours can dogs see?
It was only in the 1990’s that research found that Judy was incorrect and that dogs can indeed determine colour. The cones within the retina of the eye are what make a human and a dog see colour. Humans have three cones, whereas dogs only have two. Therefore, it makes sense to assume that they have a smaller spectrum of colour perception than humans do.
This limited colour range allows dogs to interpret yellows, blues and violets. However, they’re unable to distinguish reds, greens and oranges in the way humans see them. Instead, these colours appear on the yellow to blue scale to a dog. It is also believed that a dog’s field of vision is impacted by this weaker colour spectrum and, as such, their visibility is likely to mimic that of a humans at dusk.
It’s not all bad for dogs, though. Their night time vision is significantly greater than ours as they have more rods in their eyes and an additional layer of eye tissue, which together means they have five times the night vision of a human.
Jay Neitz, a colour vision scientist at the University of Washington found that a dog’s eyes are similar in structure to that of an individual with red-green colour blindness. Those who are red-green colour blind lack the third cone in their eye which is what deciphers these two colours.
Russian researchers have recently challenged the belief previously held by researchers that dogs solely rely on an objects colour to decipher it rather than its darkness or brightness. They found that in a small group of eight dogs, the dogs were more likely to identify a piece of paper by its colour rather than its brightness, therefore suggesting that dogs are aware of colour and use it as a means of identification.
Red-Green colour blind
An important factor to consider when training a dog is to understand the impact red-green colour blindness has on them. As a dog is unable distinguish these colours, any training involving the use of these colours could inhibit their learning. For example, it would be detrimental while training to throw a red ball into a field as the dog would struggle to locate the toy. The result is likely to be a frustrated dog that becomes easily fed up, which in turn would make the dog stop listening to his trainer’s commands. It’s also advised that the trainer doesn’t wear red as the dog could struggle to identify them or follow them as they move around.
As any dog owner will know, despite a dog suffering from colour blindness with a limited number of colours, it doesn’t appear to have any impact on their day to day lives, with the only known difficulties being associated with training. The colours that a dog can see may add to their enjoyment of day to tasks, such as playing and eating and we recommend careful colour selection when purchasing your dog’s next toy.