Can Dogs See Colors?
There’s a common misconception that dogs can only see in monochrome and use varying brightness levels to identify the outlines of items. Yet Russian scientists have now proved not only do dogs have a limited color range, they use this visual spectrum to distinguish between objects and select certain items from a line-up.
A team of researchers from the Laboratory of Sensory Processing at the Russian Academy of Sciences tested the sight of eight dogs of varying sizes and breeds. They wanted to expand on the work from the University of Washington last year.
Scientist Jay Neitz from the American university carried out experiments on dogs to test whether they could see in color or not. He discovered that while human eyes have three ‘cones’ that detect color and can identify red, blue, green and yellow light; dogs only have two. This means dogs can distinguish blue and yellow, but not red and green.
The researchers said: ‘We show that for eight previously untrained dogs color proved to be more informative than brightness when choosing between visual stimuli differing both in brightness and chromaticity.’ Although brightness could have been used by the dogs in our experiments, it was not.
‘Our results demonstrate that under natural photopic lighting conditions color information may be predominant even for animals that possess only two spectral types of cone photoreceptors.’