It's a widely known fact that dogs have a sensational sense of smell, and that they can hear sounds at much higher frequencies than us. But how strong is their sense of sight?
Apart from the widespread misconception that dogs are color blind, which is actually not the case, most of us don't know a whole lot about how well and how far our canine companions can see. If you're a little hazy on the specifics of your dog's eyesight, you might be surprised to learn that dogs are nowhere near as good at resolving details from far away as we are. However, their eyes do have a high sensitivity to motion from a distance, so it's not all bad news for our furry friends.
Signs Your Dog is Focusing on Something in the Distance
Have you ever wondered exactly how the world looks through your dog's eyes? Have you ever seen your pooch focus intently on something at a distance and thought to yourself, 'What on Earth are you looking at?'
Dogs and humans have different strengths and weaknesses when it comes to long-distance vision, and while we're generally much better at resolving details from far away, dogs have a knack for detecting motion from a long way off.
So if your long-distance eyesight is failing you, you'll need to rely on your dog's body language and behavior to get a better idea of what they're doing. The telltale sign is an intense gaze off into the distance, their eyes focused closely on whatever it is they've detected. Your pooch may start to ignore whatever you're saying and any other distractions, while you can also typically expect raised ears and body language that's alert and engaged.
Their other senses may also be put to work to identify whatever it is they've discovered. They may start sniffing the air for any odors, or begin tilting their powerful ears this way and that to discern whether what they're looking at is a friend, foe, or something that needs to be explored further.
The Science of Dogs Seeing Long Distance
How well do dogs see? That's a pretty broad question, as there are many factors that determine the strength of an animal's vision. Let's break it down into several categories to get a better idea of how your pet's eyes work.
Visual acuity measures how small a detail can be while still being visible to the eye. For humans, this is determined by reading the letters on an eye chart — if you look at the chart from 20 feet away and you can see the same line of letters as a person with normal vision can from 20 feet, you're said to have 20/20 vision. If the last line of letters you can read is the same as the one a person with normal eyesight could read from 40 feet away, your vision is 20/40.
Of course, dogs can't read letters and then recite them back to us, so their visual acuity is tested using a pattern made of black and white vertical stripes. From scientific testing, we know that dogs seem to have a visual acuity of only 20/75. In other words, while you might be able to determine a pattern from 75 feet away, your dog would only be able to make out the details of the same pattern from just 20 feet away.
There are two types of vision detector cells: rods detect light and dark, while cones detect color. Dogs have more rods than us, which means dogs are better than humans at detecting motion. Specifically, they're much more sensitive to motion at a distance — anywhere from 10 to 20 times better — which would have been a very useful skill in any pooch used for hunting.
Field of vision
Due to the location of their eyes on the side of the head, dogs have a field of vision of around 250 degrees. This is larger than the human range of 190 degrees, giving our pets around 60 degrees more peripheral vision.
Seeing in color
Dogs see the world in black and white, right? Wrong. Because they only have two color receptor cones to our three, dogs perceive green, yellow, and red as yellow, while they can also detect blue and gray.
Because of their high number of rods, dogs have superior eyesight to us in low-light situations like dusk and dawn. They also have good night vision, not only because of their advantage in the rods department, but also because they have large pupils that let more light into the eye. In addition, dogs have a mirror-like feature known as a tapetum, which reflects light back to the retina and gives the eye a second chance to capture as much light as possible.
Testing Your Dog's Vision
A certain degree of vision loss is an unfortunate fact of life for dogs, just as it is for people. So, how can you tell if your dog's eyesight isn't as sharp as it used to be?
The best way to tell is if you know what's normal for your pet. If they've started missing balls they would usually catch or stopped detecting their favorite toy from a distance, their vision may be starting to fade.
Of course, there are plenty of other obvious signs to keep an eye on, including bumping into things, general clumsiness, fearful or cautious behavior, startling easily, disorientation, and a general lack of playfulness.
If this is the case, it's worth taking a trip to the vet to get your pet's eyes checked. While a loss of eyesight isn't the end of the world, it will need to be carefully managed to help give your pet a long and happy life.
By a Labrador Retriever lover Tim Falk
Published: 04/25/2018, edited: 04/06/2020