English Scientist John Dalton, who lived in the 18th century, was one of the first people to research colour blindness. Dalton realised that he and his brother could not recognise some colours. He and his brother confused pink with blue and scarlet (a brilliant red colour) with green. This sparked his curiosity to dig deep into this phenomenon.
This defect is called red-green perception and it’s said to be the most common form of colour-deficiency in humans. Red-green colour-blind people can still tell the difference between yellow and blue, but items in red will appear grey or brown to them.
“It is caused by abnormalities in colour-detecting molecules, known as cones, in the retina. The retina is a lining at the back of the eye that converts light into electrical impulses. These signals are then conveyed, through the optic nerve, to the brain, where an image is formed,” Harriet Meyers from American Kennel Club explains. Dalton’s assertions soon spread like wildfire but the picture is still blurry as there’s no sufficient research to back them up.
Are Dogs Colour Blind?
Up until recently, it was thought that dogs are completely colour blind and can only see in black and white. But it has since been discovered that dogs can see certain colours. Dog lovers, or ‘cynophiles’ to sound fancy, will be happy to hear that dogs can, at least, make out yellow and blue as well as combinations of those colours. But what colours can they not actually see?
The widely accepted conclusion is that dogs can see colours but not in the same way that humans do. While humans can see colours such as green, yellow, violet, blue, orange and red dogs can only discern yellow, blue and some shades of grey.
“Dogs would see a rainbow as dark yellow (sort of brownish), light yellow, grey, light blue and dark blue. Dogs don’t see red, purple (violet), or orange as we do. So, while it is established that dogs see shades of yellow, blue and grey, if a dog were to look at a uniform that is red or green it would appear as faded brownish, grey or indistinct,” explains Beth Finke from The Bark.
“This means that if your dog has a red toy, it will appear brown to him, whereas an orange toy, which is a mix of red and yellow, will appear a brownish yellow. It also means that if you want to fully engage all of your dog’s senses during playtime, you should look for toys that are either blue or yellow so that they’ll stand out from the duller shades of brown and grey in your dog’s field of vision,” Hillspet’s Jean Marie Bauhaus explains further. This could explain why dogs love playing with those yellow tennis balls.
Your Dog Has Other Senses Too
Before you regret buying your dog that orange blanket cos he can’t see it as you do, keep in mind that what he lacks in vision, he more than makes up for with his other senses. Firstly, before discussing other senses, dogs have better night vision than humans to help them hunt better. Also, according to DogHealth, dogs’ ears can pick up a much wider range of frequencies than humans can including sounds that are so high-pitched that humans can’t hear.
But a dog’s hearing has nothing on his sense of smell. NOVA PBS says a dog’s sense of smell is 10 000 more powerful than that of humans, if not more. This explains why police use sniffer dogs and dogs are generally used to guide visually-impaired individuals.
“What’s more, the part of a dog’s brain that analyses smell is forty times greater than in humans. All of this means that your dog can ‘see’ more vivid pictures with his nose than we can even begin to imagine. What he lacks in poor eyesight and colour perception is more than made up for by the knowledge he gains through smell alone,” writes Bauhaus.
While you may feel bad that your dog cannot see you the same way you see him, always remember that he can tell your unique scent even when you are not around. Therefore, his nose tells him more about you than the eyes ever could. Borrowing Hellen Keller’s words, “The best and most beautiful things in the world cannot be seen or even touched – they must be felt with the heart.”
If you enjoyed this story, click here to find out what albinism is.
Tell us: Did you always know that dogs are ‘colour blind’?