When we look around us we see trees which are green. We see sky that is blue. When cats look around, what do they see? Do cat’s see color the way we do? Is the yellow we see, the yellow your cat sees? When you see a rainbow, does your cat see a rainbow?
We use our eyes to see. We use our ears to hear.
The parts of the eyes have certain names. Do you know what they are all called?
The colored part of the eye is called the iris. The black dot in the middle is called the pupil. When it is dark the pupil is large. When it is light, like bright sunlight during the day that pupil shrinks.
If you look in a mirror you can see your eyes. You can see the iris and the pupil. What color are your eyes?
Some people have blue eyes, some brown, some green. Some people have eyes that are called hazel. Hazel colored eyes are a mix of green and brown.
There are parts of the eye that we cannot see when we look at ourselves in the mirror. But these parts are important even if we cannot see them. The other parts of the eye are the cornea, the lens, the retina and the optic nerve.
The cornea is a special layer forming the front of the eye. It is transparent. That means you can see through it. It controls and focuses light as it enters the eye.
The lens is inside your eye. It sits behind the pupil. It changes the focal distance. This means it helps to make objects at various distances in focus.
The retina sits at the back of the eye. It is the inner surface which lines the back of the eyeball. The retina collects the light that passes through the pupil, and the lens. It converts the light into signals. It then sends those signals along the optic nerve to the brain.
When we look at a tree in the park. The backs of our eyeballs are collecting all those signals and sending them to our brains. And that’s how we see.
You might be wondering why this is important. How does this answer the question whether cats see color.
We know the colors that you and I see. We know that we see blues, greens, yellows and reds. One way to figure out whether cats see color like we do is to compare our eyes.
If you look into a mirror, or look at your friend’s eye what do we see?
We have two eyes.
Cats have two eyes.
Our eyes are not the same shape. Our eyes are rounder, and a cat’s eyes are pointy and slanted.
But there are differences. The shape of the pupil. Remember that is the black dot. Our pupil’s are round. Cats have slit pupils. At night, or in the dark, their pupils do open and they look round. But during the day a cat’s pupils are slits.
What other differences can you think of?
The colors of cat’s eyes are different. There are yellow, and green and blue.
I do not think I have ever seen a person with yellow eyes.
Scientists have studied cat’s eyes and compared them to humans.
Remember the parts of our eyes? Iris, pupil, cornea, lens, retina and the optic nerve. Well cats have those parts too. Both the retina in us and in cats have special cells. These cells are called photoreceptors. That is a big word. “Photo” means light. “Receptor” is a receiver. That means that these special cells receive light.
Remember that the retina sits at the back of the eyeball. It is the inner lining of the back of the eyeball. It collects the light and converts the light to signals. It then sends those signals along the optic nerve to the brain.
The special photoreceptor cells are made up of rods and cones. Both humans and cats have special cells – rods and cones.
Rods detect brightness and shades of gray. They are particularly good for night vision. The more rods an animal has in its eyes, the better its night vision. Rods are also responsible for peripheral vision. That means they are used for seeing things out of the corner of your eye.
Cones are responsible for day vision and color perception.
Scientists compared rods and cones photoreceptor cells found in human eyes with cat’s eyes.
Cats also have these special cells. But there are some differences.
Cats have more rods and they have less cones. That means they are better at seeing things at night. They do have cones, so we know that they must see some color, just not the same color that we see.
That is how we know that cats do see color. They just do not see color the same way people do.