Can dogs see colours?
When we look at a rainbow, we see shades of red, orange, yellow, green, blue, indigo and violet. But can our dogs make out the same range of colours as we do, or do they really see in black and white?
How dogs see colour has been studied for years, and the findings are genuinely striking. It's true that dogs' eyes can't register every colour humans can, but they don't actually see in black and white. Quite the opposite — their world is pretty colourful!
What colours can dogs see?
Colour is picked up by nerve cells in the eye. The retina has two main types of cells: rods, which detect light levels and movement, and cones, which distinguish colours. Human eyes have three types of cones, which can identify combinations of red, blue and green. Dogs have only two types of cones, so they can only distinguish blue and yellow. This limited colour perception is called dichromatic vision.
While humans have more cones, letting us see more colours and brighter colours than dogs, dogs have more rods, which gives them an advantage when it comes to seeing in low light or spotting moving objects.
Are dogs "colour blind"?
Colour blindness is the term used for differences in the ability to perceive colour. In humans, the degree of colour blindness depends on which colour receptors in the eye are affected. There are two main types of colour blindness in humans: red-green colour blindness and blue-yellow colour blindness. A person with red-green colour blindness can't tell those two colours apart. Similarly, a person with blue-yellow colour blindness can't tell yellow and blue apart. Dogs have red-green colour blindness.
Comparing human and dog vision
Although they can't make out the full spectrum of colours the way humans can, dogs can still perceive different colours. They're less sensitive to changes in brightness, which stops them from picking up on rich, vivid tones.
For example, red looks dark brownish, grey or even black to a dog. Our furry friends see blue well, but violet looks the same to them as blue. If you throw a ball for your dog to fetch, they can't tell the colour of the ball apart, especially if it's yellow or red. Fortunately, dogs have a fantastic sense of smell, so in most cases they can recognise their own ball and avoid confusing it with another dog's.
In some ways, a dog's eyesight isn't as sharp as ours. Dogs are more short-sighted than we are. When we look at an object from the same distance, it may look clear to us but blurry to our dogs.
