It’s normal to wonder how well your dog can see, and if he can appreciate different colors. For a long time, it was pretty well accepted that our canine pals could only see in black and white. However, it has now been proven that in fact, dogs do have color vision!
They can’t see as many different colors as us humans, which has led to them being called color blind. However, they do use their color vision to navigate the world around them and help them make everyday decisions.
Are dogs color blind? In this article, we will take a look at the latest research to find out which colors dogs can actually see and if they are color blind.
How Do Dogs See?
Firstly, it is important to understand a little about the structure and function of your dog’s eyes and how they can see. Dogs’ eyes look and function a lot like our own eyes.
- Light enters the dog’s eye by passing through the transparent thin, protective membrane at the front of the eye called the cornea.
- The light is then focused by the lens, onto the retina at the back of the eye. The lens can change shape slightly to help the dog focus on objects that are near and far away.
- The amount of light entering the eye is controlled by the size of the pupil. The pupil is the black area in the middle of the eye. When it’s dark, the pupil gets bigger to let in more light; when it’s bright the pupil becomes smaller to let less light in.
- The retina is the layer at the back of the eye, it contains special photoreceptor cells that sense light.
- Each photoreceptor cell is attached to a nerve fiber, and all these nerves bundle together to form the optic nerve. It produces continuous electrical signals that are quickly relayed to the brain to produce images.
For a better understanding of a dog’s vision, the photo placed below demonstrates how the same image is seen by humans (on the left side) and by dogs (on the right side).
Can Dogs See Colors?
Although for many years it was thought that dogs could only see black and white, it has now been proven that dogs do have color vision.
Research has shown that dogs can see different colors, and can be trained to recognize and choose between different color cards.
In this study, dogs were trained to successfully choose between yellow (dark or light) and blue (dark and light) cue cards.
However, they can’t see all the colors that we do. Their color range is much more limited, as the photoreceptor cells in their retinas are slightly different than ours.
How Do Dogs See Colors?
There are two main types of photoreceptor cells in the retina; rods and cones. These cells absorb light and transmit electrical signals, via the optic nerve to the brain, so that the dog can see. Let’s take a look at each of these important cells in a little more detail:
Rod Cells
These cells are very sensitive to light and help the dog to see in dim or dark lighting, and at night. It is thought that 97% of the dog’s retina is made up of rod cells.
Cone Cells
The cone cells are responsible for color vision and being able to see things in detail. These cells function best in bright light. Only 3% of a dog’s entire retina is made up of cone cells.
The cone cells are found in their highest concentration at the center of the retina, in an area called the fovea centralis.
Therefore, dogs are able to see some colors as they have color sensing cone cells in their retina. However, can they see all the colors that humans see?
What Colors Can Dogs See?
Humans have three different types of cone cells and each one is sensitive to a different wavelength (i.e. color) of light; longwave (red), medium wave (green) and short wave (blue).
These three types of cone cells allow us to see all the colors of the rainbow.
However, dogs only have two types of cone cells; long/medium wave (yellow) and short wave (blue).
Therefore, it is thought that dogs see the world mainly in shades of dark blue, light blue, light yellow, dark yellow and different shades of gray.
This is what a study by Neitz et al in 1989 found, but for many years some people just thought dogs were reacting to brightness and not the colors.
A more recent study in 2013 confirmed this earlier research, that dogs can see and recognize blue and yellow.
Are Dogs Color Blind?
Color blindness in people causes a reduced ability to distinguish between certain colors. A common type of color blindness in people, red-green color blindness, causes them to be unable to tell the difference between reds and greens.
That’s why dogs are often referred to as “color blind”, as they are thought to see the world in a similar way to a person with red-green color blindness. It is thought that dogs find it difficult to tell the difference between green, yellow, orange and red colors.
If your dog can’t seem to find that red toy in the green grass, he is not being lazy! It might be time to rethink what color your dog’s toys are.
Red might be bright and stimulating for us, but for dogs, it is probably quite boring and blends in with everything else!
How Well Can Dogs See?
Visual acuity is the term used to describe sharpness or clarity of vision. One study estimated the visual acuity of the average dog to be 20/75. This value means that a dog can see an object at 20 feet away, that a person with normal vision could easily see from 75 feet away.
This shows that when compared to humans, dogs are thought to have a softer, blurrier focus than we do. This doesn’t mean they are blind; it just means their eyesight is different.
Before you start thinking that dogs have really poor eyesight it is important to realize that in certain ways sometimes dog’s eyesight is better than humans!
Dogs have a much better ability to see in the dark or dim lighting than we do. Their eyes are also very sensitive to picking up slight movements and tracking motion and have better peripheral vision than we do.
Hence, why they can see a cat jump or birds fly from 50 feet away! Their other senses such as smell and hearing are also much more developed than ours, which helps them to sense and “see” the world around them.
Conclusion
Although it was long thought that dogs only see in black and white, recent research confirms that dogs can see certain colors, and they use their color vision to help them make everyday decisions.
They are thought to see the world in shades of blue, yellow and gray. As they have difficulty differentiating between some colors (such as green, red and yellow) dogs are often referred to as color blind.
They make up for slightly poor eyesight with highly developed senses of smell and hearing, to help them easily navigate their surroundings.
Although a dog’s eyesight may not be as clear or in-focus as ours, they do have a few one-ups on our eyes, as they have superior night vision and better motion awareness too!
