Understanding Dog Vision, Color & In the Dark

Among the most cited research articles on dog vision is this 1995 article by Chris and Paul titled ‘Dog Vision. The article published in the Journal of American Veterinary Medical Association proved most useful in answering key questions dog owners have such as;

• How do dogs see?
• Do dogs see in color or in black and white?
• How do dogs see humans?
• Are dogs colorblind?
• How well do they see?
• How far can dogs see?
• What do they see at night?
• and many more..

Chris and Paul’s article has been quoted more than 250 times and I was able to study it in detail and have broken down the answers I got from it and from other sources in this article.

Let’s by understanding the fundamentals of dog vision:

Dog vision is dependent on a number of factors such as;

• Field of view: Dogs have a poor field of view of 30-60 degrees compared to 140 degrees in humans. This doesn’t mean humans are better at seeing than dogs, it just means we see more because our eyes are on the front of our head while a dog’s eyes are on the sides.
• Eye Structure: The dog’s eye is similar to a human’s but there are some notable differences. For example, the cornea (the part of the eye that covers the iris and pupil) is flatter in a dog than in a human. This flattened shape means that light entering the eye isn’t focused as well as it is in humans.
• Depth perception
• Vision acuity
• Color perception and form
• Light perception and motion
• Eye placement

Dog evolution and their visual performance:

In the wild and before their domestication, dogs are crepuscular, which means that they are most active at dawn and dusk. This is because their prey is also most active at these times. Since they need to see their prey in dim light, dogs have evolved to see in low-light conditions.

Dogs have retained the advantage to see in the dark but have retained good function under a wide array of lighting conditions, including daylight. We cannot make the case that dogs have specifically good vision in diurnal or nocturnal conditions but a good description of their evolution is that they have “evolved for an arrhythmic photic existence” or have evolved to function in a variety of light conditions.

Dogs have a number of features that allow them to see well in low light

• Large pupils: Dogs have large pupils which allow more light to enter their eyes.
• Light-reflecting tapetum: The tapetum is a layer of tissue at the back of the eye that reflects light back through the retina, increasing the amount of light that is available for vision. This is what makes a dog’s eyes appear to glow in the dark.
• Rod dominance: Dogs have more rods than cones in their eyes, which makes them more sensitive to light. This is why they can see better in the dark than humans.
• Convergence: Dogs have a greater degree of convergence than humans, which means that their eyes point in slightly different directions. This gives them a wider field of view and allows them to see better in the dark.

How do dogs see?

Dogs see the world differently than humans do, but not as different as you might think. Dogs can see colors, but they are not as good at distinguishing colors as humans are. This is because they have fewer cones in their eyes than we do.

Unlike humans, dogs are dichromatic and only have two cones. Cones are responsible for color perception and because of fewer cones than humans, they are only able to see fewer colors.

However, dogs make up for this by having better night vision than we do. This is because they have more rods in their eyes, which makes them more sensitive to light.

Finally, dogs have a greater degree of convergence than humans do. This means that their eyes point in slightly different directions. This gives them a wider field of view and allows them to see better in the dark.

Do dogs see in color?

For a long time, the myth that dogs only see in black and white was widely accepted. However, we now know that this is not the case. Dogs do see colors, but they are not as good at distinguishing colors as humans are.

This is because they have fewer cones in their eyes than we do. Cones are responsible for color perception and because of fewer cones than humans, they are only able to see fewer colors.

Which colors can they see and why?

Dogs can differentiate wavelengths from about 440 to 520 nm (the region that includes what appears as violet, blue, blue-green, and green to people). It is, however, important to note that light in these wavelengths appears to be the same color to dogs and people.

Wavelengths that correspond to blue, yellow, and violet are visible to dogs. However, they cannot see the colors red, green, and orange because these colors are outside of their range of vision and appear somewhere in their blue and yellow spectrums.

Dogs can see Short-wavelength light such as blue light but cannot see long-wavelength light such as red light.

However, dogs make up for this by having better night vision than we do. This is because they have more rods in their eyes, which makes them more sensitive to light.

Can Dogs See In The Dark?

Dogs have evolved from being animals active during dawn and dusk which is their habit in the wild. As they evolved, they retained their superior capabilities to see in low light conditions but they do require some small amount of light to be able to see. This study revealed that they can see 5 times better than humans in the dark

Light essentially allows dogs to see by triggering a series of electrical impulses that eventually reach the brain and are interpreted as images. When not enough light is present, these electrical impulses are not triggered, and therefore dogs cannot see.

To see in the dark, dogs need light just like we do – however, their eyes are built in a way that allows them to make better use of any available light.

Dogs have large pupils that let in more light than ours do, and they also have a layer of tissue at the back of their eye called the tapetum that reflects light back through the retina, increasing the amount of light that is available for vision.

In addition, dogs have more rods in their eyes than we do. Rods are sensitive to light but cannot distinguish colors the way cones can. This is why dogs see in black and white.

The combination of these factors makes dogs’ night vision superior to ours, but it is important to note that they still need some small amount of light to be able to see.

How well can dogs see compared to humans?

Dogs have better eyesight than humans in several ways, but they also have some limitations that make our vision superior to theirs. They have a limited field of view and have fewer cones compared to humans.

The field of view is the area that can be seen at one time. Humans have a field of view of about 140 degrees, while dogs have a field of view of only about 30 to 60 degrees.

This means that dogs cannot see as much at one time as we can. However, they make up for this by having better peripheral vision.

Peripheral vision is the area that can be seen to the side while looking straight ahead. Dogs have a peripheral vision of about 250 degrees, while humans have a peripheral vision of only about 100 degrees.

This means that dogs can see more to the side than we can, but they cannot see as much in front of them.

Dogs also have fewer cones in their eyes than we do. Cones are responsible for color perception, and because of fewer cones, dogs can only see a limited number of colors. Human eyes have three types of cones that allow us to see red, green, and blue light. Dogs have only two types of cones that allow them to see blue and yellow light.

This means that dogs cannot see the colors red, green, and orange. However, they can see the colors blue and violet.

Dogs also have better night vision than we do because they have more rods in their eyes. Rods are sensitive to light but cannot distinguish colors the way cones can.

Dogs have 20/75 vision, which means they can only see at 20 feet what a human with 20/20 vision can see at 75 feet.

While this may seem like poor vision, it is actually pretty good considering that dogs do not have hands to help them judge distances.

Do some breeds see better than others?

Anatomical differences have been explained to be the main cause of dog vision divergence among breeds and no vision advantage has been identified in certain breeds.

I found some online write-ups claiming that some breeds that were bred for hunting or herding often have better eyesight than other breeds but I couldn’t find any peer-reviewed study to back up the claim.

Going back to dog’s anatomy, the eye positioning in a dog’s skull can also affect its vision.

For example, dolichocephalic (long-headed) dogs like Greyhounds have their eyes set more to the sides of their skulls whereas brachycephalic (short- or broad-headed) dogs like Pugs have their eyes set closer to the front. This difference in eye positioning leads to a difference in how much the eyes can move and, as a result, how wide of an area these breeds can see.

The more the eyes can move, the wider the area that can be seen.

Form Perception in Dogs:

Form perception in dogs is the ability to see an object and recognize it as being a specific shape.

For example, a dog can see a ball and recognize it as being a round object.

Dogs are able to form perceptions of objects very quickly, but they are not as good at recognizing more complicated shapes.  Discriminating a circle from an ellipse was found to be easier for them.

Dogs also have the ability to differentiate between horizontal and vertical lines. A study was conducted in which dogs were shown various images on a computer screen and their responses were recorded. The results showed that the dogs could distinguish between horizontal and vertical lines better than they could distinguish between diagonal lines.

FAQs

Do dogs see in the dark like cats?

A dog can see in the dark but they are not as good as cats that have large corneas. Dogs, however, have also evolved to be good at seeing in low-light conditions and have more rods in their eyes. Both cats and dogs are not nocturnal and still require some light to be able to see.

How do dogs see humans?

Dogs can perceive form and have been known to differentiate vertical from horizontal forms. They also can differentiate circles from ellipses and these capabilities give us an idea that they can see humans quite well.

As intelligent pets, dogs are known to recognize humans by their faces and can distinguish between familiar and unfamiliar faces. Research suggests that they can even tell the gender and age of a human by looking at their face.

Are dogs color blind?

No, dogs are not colorblind but can only see fewer colors compared to humans.

Dogs have two types of cones in their eyes that allow them to see blue and yellow light. This means that dogs cannot see the colors red, green, and orange but they can see the colors blue, yellow and violet, colors with short wavelength.

Can dog see better than humans in the dark?

Yes, dogs can see better than humans in the dark because they have more rods in their eyes. Rods are light-sensitive cells that allow us to see in low-light conditions but cannot distinguish colors.

Dogs also have a tapetum lucidum, which is a reflective layer of tissue behind the retina that helps them see better in the dark. When light hits the retina, it is reflected back and this allows the rods to absorb more light, giving dogs better night vision.

Studies have shown that they can see up to 5x better than humans in the dark.

How far can dogs see?

Most dogs have 20/75 vision which means that they can need to be 20 ft from an object to see it well as a human standing 75 ft away. This is because the size of their pupils is smaller than ours.

In other words, dogs can see objects that are 20 feet away very well but if you place the object further than 20 ft, they may not see them clearly.

Dogs with dolichocephalic skulls have better distance vision whereas dogs with brachycephalic skulls have a better close-up vision.

Some ‘seeing-eye’ dogs breeds such as labradors may see further than 20 ft but are not as good as humans

How well can dogs see?

Dogs can see but not as well as humans as they have a dichromatic vision that makes them unable to perceive some colors and are better at perceiving short-wavelength lights within shorter distances, compared to humans. They can see clearly if objects are placed within 20 feet but the objects get unclear to them when they are over 20 ft. away.

They, however, have better vision in low-light conditions as they have more rods in their eyes and a reflective layer of tissue known as the tapetum lucidum.

What do dogs see at night?

On pitch-dark nights, dogs cannot see very well but are better than humans. Similarly, on nights with some light, they can still see better than humans. Why? Dogs have originally been active at dusk or at dawn as that’s when their prey would be active as well and they have evolved to develop the advantage to see well in low-light conditions.

Dogs see at night but not as well as they do in the daytime. This is because they have more rods in their eyes that allow them to see in low-light conditions.

They also have a reflective layer of tissue known as the tapetum lucidum which helps them see better in the dark. When light hits the retina, it is reflected back and this allows the rods to absorb more light, giving dogs better night vision.

Studies have shown that they can see up to 5x better than humans in the dark.