Are dogs color blind? That's a question many pet owners and dog enthusiasts often ask. While it was long believed that dogs could only see in black, white, and shades of gray, evidence suggests they can also see brown, yellow, and some shades of blue.
Can Dogs See Color?
The short answer is yes, dogs can see color, but they can't see as many colors as you do. Based on the number and types of cone photoreceptor cells dogs have, it's likely that they see colors ranging from brown through yellow, shades of gray, and just a few shades of blue. Because the red and green portions of the spectrum aren't distinguishable to them, dogs likely perceive those colors as muddy shades of gray. To gain a better understanding of why this is, it's important to break down the anatomy of the canine eye.
Differences Between Dog and Human Eyes
The eye is an amazing organ, whether it is a dog's eye or a human's eye. While there are many similarities in how both types of eyes are constructed, there are a few crucial differences that affect the way dogs see things as compared to people.
Rods and Cones
The eyes contain two different types of photoreceptor cells that affect the way everyone sees things, and this is true of both dogs and people. The name of each type of these cells refers to its actual shape.
- Rods - These photoreceptor cells are rod-shaped, as their name implies, and they are very sensitive to light.
- Cones - Cone-shaped photoreceptor cells come in three different types. They detect colors and shapes, but they are less sensitive to light than rod cells.
This is where the major differences between dog eyes and human eyes come into play. Rod cells and cone cells are both found within each species' retinas, but a dog's eyes contain mostly rod cells. Due to this abundance of rod cells, dogs can see far better in the dark than people can.
At the same time, dogs also have fewer cone cells than human eyes contain, and they only have two of the three different types of cone cells. This naturally limits their ability to see color.
Are Dogs Color Blind?
The light spectrum contains a full range of colors, and dogs and people differ in how many of those colors each species can see. According to scientists, dogs have dichromatic vision. This means they can only see certain parts of the color spectrum because they only have two types of cone cells.
People, on the other hand, are trichromatic. This is because humans typically have all three types of cone cells. When this is the case, they have the ability to see the entire color spectrum. However, some individuals do not have all three types of cones in their retinas. This means that these people experience some measure of color blindness.
The fact that dogs have fewer cone cells in their retinas definitely affects how they perceive colors. However, they're not color blind in the sense that they cannot view colors at all. Instead, they see much the same colors that a person who is red-green color blind would.
Which Colors Dogs Actually See
Due to a dog's lower number and fewer types of cone cells, it's safe to assume that canines see fewer colors than people do. Additionally, the colors that they do see may very well appear more washed out when compared to the way people perceive color. Yellows, blues, browns, and greys make up the majority of their color spectrum.
Lack of Visual Detail
In addition to a dog's limited color vision, their eyesight in the daylight is not as detailed as humans. While the standard vision of a human is 20/20, the average dog's visual sharpness is reportedly a mere 20/75, meaning a dog must stand 20 feet away from an object in order to see it with the same detail a human can visualize from 75 feet away. Data suggests that even in dim light, a person's vision is three times more sharp than a dog's vision.
However, this may not ring true for all breeds, as some say Labrador Retrievers may have visual acuity close to a human's 20/20 vision. All dogs also reportedly have difficulty seeing anything closer than 10 inches in front of them. This might explain why owners often have to go to great lengths to help their pet find something that's right in front of their nose! However, what dogs lack in depth perception and detail, they make up for with other visual qualities.
- Wide peripheral vision: Most dogs have a visual field of view of about 240 degrees (compared to 180 degrees in humans). Their exact field of vision depends on the dog's head shape, snout length, and eye placement. A Sighthound like the Greyhound can have a visual field up to 270 degrees, whereas a brachycephalic breed like the Pug might have a range of only 220 degrees. Even so, this field of view is still greater than that of a human's field of view.
- Ability to see in the dark: The anatomy of a dog's eye and distribution of photoreceptor cells give them improved vision in low light conditions. That's not to say that dogs have natural night vision goggles, but they can get around in the dark much better than humans.
- Sharp motion sensitivity: Again, thanks to their abundant rods, dogs can recognize motion over great distances. According to a study involving police dogs, they could see a moving object up to half a mile away, whereas they had to be much closer to the same object when it was motionless in order to recognize it.
The Importance of Color to Dogs
Since it's impossible for people to truly view the world through a dog's eyes, scientists can only create logical theories based on their research. In the big scheme of things, color doesn't appear to play a significant role in a dog's vision, at least not the way it does to a human.
You need only look back at the dog's ancestors to understand that the ability to see in the dark and detect movement was most important for their protection, ability to hunt, and ultimate survival, and this is likely why their eyes developed with an emphasis on light and motion rather than color.