If you could imagine a scene from your dog's life as seen through your dog's eyes, what would it look like? If you and your dog were at the dog park, you throwing a fluorescent yellow tennis ball and him chasing it through the bright green grass, would your dog be able to see those colors? Or would the scene through his eyes be black and white?
There's a perception that a dog is colorblind, which many people think means they can see only in black and white. The reality is a little different. Thinking that a "colorblind" dog can see only in black and white is actually a huge misinterpretation. Dogs actually do see colors, but they just don't see them the same way that people do.
Dog vision vs. human vision
It was accepted for decades that dog vision meant only seeing black and white, and that's still what many people think. But scientists understand dog vision and their eye anatomy better now than they used to. Mot people are familiar with the concept that eye cells called rods and cones transmit data to our brains that allow animals to see color.
Humans and dogs have both rods and cones, although dogs have more rods than cones in their retina, whereas people have more cones. Each type of cone detects a different wavelength of light, and because humans have three types of cones that absorb red, green and blue wavelengths, we can see a full spectrum of color. Dogs, though have only two type of cones, which means they can see yellow and blue colors, but those colors are not as rich and vibrant as what humans see. Dogs are also more nearsighted than humans.
Dog vision seems to be 20/75, which means that as a human, you could see a scene clearly at 75 feet, whereas a dog would ned to be at 20 feet to see this same scene. Rods are responsible for peripheral and night vision. Cones transmit day vision and color perception. And interestingly, some animals such as birds and fish have a fourth type of cone receptor that allows them to see ultraviolet light.
Our understanding of being colorblind dates back to the early 1800s, when English scientist John Dalton started studying it after he realized that his brother confused red with green and pink with blue. This inability to see red and green is the most common form of different color perception. This too, has to do with rods and cones; an abnormality on the color-detecting part of the cone, to be precise. Red and green colorblind people will see red as gray or brown, although they can still see yellow and blue.
Recent studies from Italy indicate that dog vision is similar to that of red and green colorblindness in humans. This means your dog can likely see the blue sky and the yellow flowers in the field of grass. But the green grass itself likely looks grayish-brown, as if it were straw instead.
Because colors are blends of the primary colors, dogs can not see colors that are blends of red and green or that include those color components, such as pink, purple, or orange. Dogs are also unable to detect changes in brightness, so when the sun goes behind a cloud when you're at the dog park, your dog probably can't tell.
What colors can dogs see?
Dogs can see shades of yellow, blue, and brown, as well as various hues of gray, black, and white. So actually, your dog can see that bright yellow tennis ball you throw at the dog park, but the problem is that the grass probably looks yellow too. When choosing toys, keep this in mind and try choosing a blue ball or a blue chewy, not a red one.
Many of the dog accessories on the market are red and green, but now we know that your dog can't really tell the difference between that red Santa hat or the green elf coat you tried to make him wear for your last holiday card! Take a look at the color of your carpet and the color of the dog bed you got him, and see if he can tell where he's supposed to be sleeping. Maybe that's why he never seems to know where to go when you tell him to lay down!
Dog vision and safety
There may be some safety concerns based on the colors your dog can see. For instance, if you're throwing a ball for your dog and there are red cars parked on green grass, it's possible your dog may not be able to tell the difference.
If you want to see a visual comparison of what your dog can actually see, check out the site Dog Vision. They have charts of gray scale and color spectrums to give a side-by-side comparison of how human vision and dog vision is different. The site also lets you upload a photo if you want to see how your dog would view the scene.
The common perception that dogs only see in shades of black and white is not correct. Dog vision is actually similar to that of red and green colorblindness in humans. Dogs can see colors, but do not see them with the same vibrancy that we see them. Dogs can see shades of yellow, blue, and brown, as well as various hues of gray, black, and white.