Dogs Are Not Quite Colour Blind

Despite what you may have heard in the past, the vision of a dog is not simply black and white. In fact dogs just like their human owners have multi coloured vision. The only difference is they cannot see as many different colours as their handlers. The reason for this is because the retina of a dog has only two types of colour detecting cells (cones).

In contrast the human retina for the most has three types of cones which allows us to see more wavelengths along the visible spectrum.

Jay Neitz of the University of Washington found that the colour perception of the canine is very similar to a red-green colour blind person. These people just like dogs only have two cones with which to detect colour.

Dogs perceive colour quite differently to humans who have normal vision. Dogs perceive red as darkish brown, whilst green orange and yellow all appear to be yellowish in colour. Something which seems to be blue green to humans such as a pool of water or the ocean just seems grey to a dog whilst purple objects appear to be blue.

The research by Dr. Neitz suggests that just like colourblind people, dogs may use certain types of cues to tell one colour from another.

“A lot of the time there are good cues to help them figure it out; for example, red objects tend to be darker than green objects. So, if it’s a dark apple, a red-green color-blind person would know that it’s probably a red one, and if it’s a lighter apple, it may be a Granny Smith.”Dr. Neitz said

Despite the fact they may be colour blind it does not mean a human’s eye sight is better than their canine counterpart. Researchers have found that dog sight has evolved in such a manner that they are able to see clearly even when light is absent.