“A human would be missing the sensations of red and green,” Neitz said. “But whether or not the dogs sensations are missing red and green, or if their brains assign colors differently, is unclear.”
Dogs are not completely colorblind, but their eyes are structured in a similar way to those of people with red-green color blindness, whose eyes also lack the third kind of cone normally present in humans, Jay Neitz, a color vision scientist at the University of Washington who conducted many of the modern experiments on color perception in dogs, told Live Science.
The researchers discovered that dogs — or at least the whippets, pugs and the single Shetland sheepdog that participated in the experiments — were very nearsighted. The results of the experiment suggest that dogs, in well-lit conditions, have roughly 20/50 vision. This means that they have to be 20 feet (6 meters) away from something to see it as well as a human who is 50 feet (15 m) away from that same object.
To see blue and yellow, dogs and humans rely on neurons inside a part of the eye called the retina. These neurons are excited in response to yellow light detected in the cone cells (which are also inside the retina), but the neurons activity gets suppressed when blue light hits the cones. A dogs brain interprets the excitation or suppression of these neurons as the sensation of yellow or blue, respectively. However, in dogs and in people who are colorblind, both red light and green light have a neutral effect on the neurons. With no signal to interpret these colors, the dogs brains dont perceive any color. Where you see red or green, they see shades of gray.
Many dog breeds (though not some of the toy dog breeds) also have a special eye layer, known as the tapetum lucidum, that bounces light back toward their retinas, essentially magnifying the light that does reach the rods there, according to a 2014 study in The Journal of Veterinary Medical Science (opens in new tab). The tapetum lucidum is what causes dogs eyes to glow a bluish green when light shines on them at night, according to the Merck Veterinary Manual.
What colours can dogs not see?
Dogs can not see the colours Red, Green, nor Orange, Purple or Brown. These colours appear as a shade of grey in a dog’s vision.
Can dogs see the colour red?
Dogs can not see the colour red as the cones in their retina only detect blue-violet and yellow.
How Animals See The World
Visual enrichment is very important to your dog and there are many toys in an array of colours that we love to play with, but what colours can your dog actually see?
Dogs have dichromatic vision, which means they see violet-blue, yellow and shades of grey. This is similar to a human being red-green colour blind. Dogs are typically nearsighted with a wider field of view than a human giving them better motion detection.
Seeing is part of how dogs enjoy their environment and we can help stimulate their senses through visual enrichment. Choosing toys, playing games and training our dog with visual cues that they can perceive and understand plays a big part in how happy and fulfilling their lives can be. Here’s how you can choose the things around you to help your dog see the world in a better light.
We know that a dog’s eye is different to a humans. The retina, which is the light sensitive part of the eye, contains rods and cones. Cones for colour and detail and rods for motion and vision in dim light.
Dogs retina’s are predominantly rods so they can see really well at night as well as enabling them to be much better at detecting motion. Squirrel!
Unfortunately, this means that your dog does not have many cones, so we do not see the same colour spectrum.
Dogs’ retinas can only interpret two colours. A blue-violet and yellow. Everything else is a shade of grey. Your dog uses other indicators to help them identify objects, such as sense of smell, textures, brightness and position.
This is how a guide dog knows when to cross the road. They can’t see the colour of the red and green traffic light, but they have learnt the context of the traffic noise and motion to allow them to help their owners safely cross the road.
However a recent study in 2019 showed that although dogs can not see more colours, they are able to discriminate using luminance levels.