- Not a substitute for professional veterinary help.
Your dog’s vision surpasses yours in a few major ways. However, they can’t see color as well as you can, since all dogs are colorblind.
Of course, while their favorite ball may not look the same to them as it does to you, colorblindness doesn’t affect your dog’s day-to-day activities much. Plus, other elements of their eyesight help compensate.
For example, dogs are highly skilled at detecting motion, says Dr. Chris Dixon, a veterinary ophthalmologist and clinical director at Veterinary Vision. They also have superior low-light vision compared to humans.
Dogs also have top-notch hearing and sense of smell, and these senses do even more to help them navigate their environment.
Read on to learn more about colorblindness in dogs and other unique elements of canine vision.
Why Are Dogs Colorblind?
Dogs are colorblind due to the structure of their eyes. The human eye has three types of photoreceptors, or “cones,” in the retina, Dr. Dixon explains. These light-sensitive cells help the brain distinguish different colors. Dogs’ eyes only have two cones.
“This limited color perception is a result of evolutionary adaptations,” Dr. Dixon says. “Dogs are descendants of wild dogs and wolves, and their ancestors were crepuscular hunters, meaning they were most active during dawn and dusk when color vision is less critical.”
“Instead of color, dogs relied on motion detection and a keen sense of smell and hearing to track prey. Over time, the canine visual system has adapted to these conditions, prioritizing low-light vision and motion detection over color discrimination,” Dr. Dixon adds.
That said, experts believe dogs still do pay some attention to color. One study found that dogs prompted with cues that varied in either brightness or color quality were more drawn to stimuli by color over brightness.
Which Colors Can Dogs See?
While the term term “colorblind” may suggest a complete lack of color vision, this isn’t necessarily the case. Colorblindness more often means seeing a more limited range of color. (This applies to affect people, too: Around 8% of men and 0.5% of women have limited color vision.)
For years, people thought dogs only saw things in black and white. However, researchers at the University of California discovered in the late 1980s that they could see color, just on a more limited spectrum than humans. Since then, other studies have explored the extent of dogs’ color vision and how they use color as a cue.
Dogs have dichromatic vision, which means they primarily see the world in shades of blue and yellow, Dr. Dixon says. “They cannot distinguish between red and green colors because they lack the specific photoreceptor cells for these.”
The absence of certain photoreceptors also means dogs can’t detect shades such as purple and orange.
Scientists have determined which colors dogs can see by examining the photoreceptors in close detail and by measuring electrical activity under different colored light, Dr. Dixon adds.
Do Dogs See Well At Night?
Dogs have excellent nighttime vision, and not just because colors are far more muted during these hours.
While humans have more cones in the retina, dogs have more rods, or cells that are sensitive to light. The photopigments in these rods, which absorb light, are also more sensitive. This helps them see much better in dim light conditions, Dixon says.
Dogs also have a part of the eye called the tapetum lucidum. It’s thought this layer reflects light that’s already been “taken in” by the eye back onto the photoreceptors. As a result, dogs see better in low-light conditions. This is why you might notice your dog’s eyes shining at night.
How Far Can Dogs See?
Dogs may not have the best color vision, but other aspects of their eyesight have developed to help them in essential activities, such as hunting.
For instance, they can see much better than people when it comes to seeing things in front and to the side. Their total field of vision can reach 240°, while a person’s field of vision only extends to about 180°.
On the flip side, their depth perception isn’t as good as yours, since their eyes have less binocular overlap. This refers to the space in front of you that both of your eyes view at the same time. A lack of depth perception makes it harder to gauge how far away something really is.
Experts do believe, however, that dogs can better recognize objects farther away when the object is in motion. One study found dogs could recognize moving objects up to 900 meters away but could only recognize static objects up to 585 meters away.
Can Dogs See Detail As Well As People Can?
Dogs are better able to see objects at a distance, but when it comes to visual acuity, or the ability to notice fine details, people take the prize.
A person with great eyesight has 20/20 vision. However, a dog’s vision is more like 20/75. This means if there’s an object you can see clearly from 75 feet away, your dog can only see it clearly from about 20 feet away.
Still, dogs hold the trump card for some elements of sight. In addition to better motion and low-light vision, they’re more sensitive to things like flickering lights and moving images on screens, due to the higher number of rods in their eyes.
It’s important for pet parents to understand their dog’s visual abilities, Dr. Dixon emphasizes. This can help you appreciate the world as they see it, which can strengthen the bond between you!