Robert is a life-long dog-lover and the co-creator of Telemark's Guide to Dogs, an interactive CD-ROM filled with dog information & photos.
Are Dogs Really Color Blind?
Most dog lovers know that the answer to the question, "Are dogs color blind?" is “Yes, dogs are color blind.” But that doesn’t mean what you may think. For many years, it was commonly believed that dogs saw the world in tones of gray, like an old black-and-white photograph or TV image. That belief can probably be attributed to Will Judy (founder of National Dog Week), who wrote in a 1937 dog-training manual that dogs could only see shades of gray. Will was a widely published author, so his views quickly spread.
The view was supported by many scientists who until the 1960s generally believed that only primates and a few species of birds had the ability to see colors. Today, through experimentation and through a better understanding of the eye, we know that many animals have color vision, but few can perceive the full range of colors seen by humans.
Dogs, in particular, have red-green color blindness, which is also the most common form of colorblindness in humans. Dogs can see blues and yellows much like we do, but greens and reds are seen as shades of brown or gray… much like the picture at the top of this page.
How Dog and Human Eyes Differ
Our eyes have two types of light receptors called rods and cones. Rods are simply light detectors, whereas cones respond to different frequencies of light (in other words, different colors).
- Humans are trichromatic. We have three types of cones, which correspond roughly to red, blue, and green.
- Dogs, on the other hand, are dichromatic.They have two types of cones that correspond roughly to blue and yellow.
Dogs have a higher percentage of rods than humans. That means dogs are better at seeing in low-light conditions. Due to the high percentage of rods, dogs are also better at detecting motion.
However, dogs are quite nearsighted by human standards. Most dogs have the equivalent of about 20/75 vision. A dog could only read the first three lines of an optometrist’s eye chart (although reading an eye chart at all would be quite a feat for a dog!) Dogs see close-up objects much as humans do, but distant objects are very blurry.
What This Means for You and Your Dog
Bright red dog toys look great to humans but are pretty dull for your dog. Who wants to play with a gray toy? If you toss a red ball in a field of grass, it’s very hard for your dog to see. (Unless it’s still rolling . remember, your dog is great at seeing motion.) Look for blue and yellow toys, which look bright and exciting to dogs, and are easy for them to see.
The world of dog agility is also starting to recognize dogs' visual limitations. Dog agility equipment are now using blue and yellow as the main colors more frequently. Many dog agility organizations have now established rules that landing surfaces and contact zones should be painted yellow, with contrasting areas in blue. Another alternative is to stick with black and white, using white for contact surfaces, and black for contrast.
Do All Dogs See Alike?
Surprisingly, there is almost no data to answer this question. Scientists have not studied the differences in vision among different dog breeds.
While it’s doubtful that any breed has independently evolved trichromatic color vision, it’s quite likely that some breeds have sharper vision that others, just as some breeds have a better sense of smell. And of course, just as in humans, eyesight will vary from individual to individual.
Don’t Feel Sorry for Your Dog
While dogs can’t compete with humans when it comes to seeing, their other senses are far better than ours. Dogs can detect sounds at about four times the distance that humans can hear. They can also hear much higher frequencies (67–45,000 Hz, versus a human range of 64–23,000 Hz). Dogs have more muscles in their ears, allowing them to move their ears to better detect the direction of sounds.
Dogs have 150–300 million scent receptors, depending on the breeds, compared to 5 million for humans. The portion of the dog’s brain devote to analyzing scents is about 40 times as great as a human's. Scientists estimate that a dog’s sense of smell may be 10,000 to 100,000 times better than a human’s. To put this in perspective, a human might detect the sweet scent of a teaspoon of sugar in a cup of coffee . but a dog can smell a teaspoon of sugar added to an Olympic swimming pool!
Due to the differences in our senses, dogs and humans experience the world differently. Understanding the differences can help us be better friends and companions.
© 2019 Robert Nicholson
Ariana Riel on October 12, 2019:
Me too. But dogs don’t know that. Because they were born to see these colors. It’s normal for them.
Bailey Loyd on October 09, 2019:
Boy, do I feel bad for dogs
Are dogs colorblind?
Humans have three different types of cones in their eyes and each type of cone is designed to distinguish a specific wavelength of light. Combined, these three types of cones allow the average human to distinguish a staggering one million colors or more. Dogs and other mammals are dichromats, which means they have only two types of cones. This doesn't mean that they see the world in black and white, only that they can distinguish fewer colors than the average human. Don't feel too sorry for your canine companion, however even with just two types of cones, he can see somewhere around 10,000 different shades [source:Greenwood].
Doggie vision is very similar to that of humans with red-green colorblindness [source:UCSB ScienceLine]. Like humans with this condition, dogs can easily interpret colors with shorter wavelengths, but may have trouble with longer wavelengths. They see a rich spectrum of colors, but may mix up shades of red and green, or those with any red or green components, like purple or blue-green. Since they are unable to distinguish the color red, they simply interpret it as dark brown. All yellow, green or orange objects appear in various shades of yellow or yellow-brown. Purple, which consists of red and blue, looks like pure blue to dogs because they can't interpret the red component. The blue-green hue of oceans and other water bodies likely appears to your dog in various shades of grey [source:Palmero].
To keep things simple, consider the acronym ROYGBIV, which is commonly used to help students remember the colors of the rainbow. While the average human can see the full spectrum of color from red to violet, a rainbow appears slightly different to dogs. Instead of gradually transitioning from red to orange, yellow, green, blue, indigo and violet, a dog's visible spectrum starts with a deep brown, transitioning into lighter brown, yellow, grey, light blue then dark blue.
Keep your canine's color capabilities in mind next time you're shopping for the perfect toy for your best friend. Skip the bright red, which appear as muddy brown to your pooch, and stick to colors like blue or yellow that your dog can truly appreciate.
Can Dogs See Colors?
Although for many years it was thought that dogs could only see black and white, it has now been proven that dogs do have color vision.
Research has shown that dogs can see different colors, and can be trained to recognize and choose between different color cards.
In this study, dogs were trained to successfully choose between yellow (dark or light) and blue (dark and light) cue cards.
However, they can’t see all the colors that we do. Their color range is much more limited, as the photoreceptor cells in their retinas are slightly different than ours.
For the most part, dogs' eyes are very similar to human eyes in structure and function. Eyes detect colors through light receptors in the retina called cones. When the cones are stimulated, they transmit that signal (color) to the brain. Rods, also in the retina, respond to shades of black and white and are sensitive to changes in light.
Humans and dogs have both rods and cones, but not the same amount of each. Dogs have many more rods than humans do, causing them to see far better in low light, which is great for hunting prey in the nighttime. Cones control color perception and allow the differentiation of different colors. Humans, however, are trichromatic, meaning they have three cones in the eyes that allow us to see all the colors of the rainbow. Dogs are dichromatic, so they are limited to two cones, which reduce the number of pigments they perceive.
Humans can see violet, blue, blue-green, green, yellow, orange, and red. Dogs can see shades of blue yellow, and gray. In fact, dogs' vision can be compared to a person suffering from red-green color blindness (deuteranopia). Red, yellow, or green objects are perceived as yellow. Blue and purples objects are perceived at blue, and cyan or magenta objects are perceived as gray.
Are Dogs Really Color-blind?
What’s the single biggest myth you know about dogs? There are certainly many to consider, and several of which you might not even realize are myths. For instance, dogs don’t ONLY eat grass when they are sick, dogs’ mouths aren’t cleaner than the human mouths, and a dog’s age isn’t quite equal to seven human years. But the single biggest canine myth of all is almost certainly the misconception that dogs are all completely incapable of seeing color.
Is it true? In short, no. Modern science has debunked this time and time again, finding that dogs are not color-blind in the way that many believe, which is that they see the world completely in black and white (or even in grey-tinted tones). In reality, dogs are only partially color-blind, meaning they can see colors, but they perceive them more like humans with red-green color blindness do as opposed to the majority of us with “normal” eyesight.