Is a dog ’ s life monochrome?

Do dogs live in a black-and-white world? As a child, I remember my mother telling me something she learned when she was an eye nurse – dogs are colourblind. Now, if I remember rightly, she didn’t mean they could only see in black and white as research in the 1940s had suggested, but that they had limited receptivity to the full colour palate. They were red-green colourblind, like some boys and men. The issue came up after they tested us boys at school for colour blindness with those spotty number colour charts. The red colour of our lab’s collar would’ve looked grey to her However, proof that the canine world isn’t monochrome didn’t come until 1989, so my mother, as was often the way, was way ahead of her time. Anyway, that proof demonstrated that dogs have dichromatic eyes. They have two types of colour receptor, cones, in the retinas of their eyes based on two pigments. Specifically, they can see various colours just not as many as the average human. People are generally trichomats, they have three colour receptors, for red, green, and blue and a set of combinations thereof. For most people, there are lots of colours in between the violet, indigo, blue, green, yellow, orange, and red of the rainbow. Although, as I’ve mentioned before while not everyone agrees on the existence of indigo, there really is a much greater gamut of colours in there! Generally, we can discern a million or so colours, hence the seemingly endless parade of o...
Source: David Bradley Sciencebase - Songs, Snaps, Science - Category: Science Authors: Tags: Biology Source Type: blogs