domestic cats

Why do cats eyes glow in the dark?

Cats are amazing and unique animals. Not without reason they had a special attitude in different cultures. Some considered them sacred animals, others attributed them to the servants of the dark forces and were afraid. One reason is the uniqueness of their vision. Everyone knows that in the dark their eyes flash with bright lights. Let’s see if there is even a grain of mysticism in this.

How is the cat’s eye?

If you compare the human and cat eyes, you can find a number of differences. It is they who determine the peculiarities of their vision. We do not want to confuse you with abstruse biological terms, so we will try to talk about how the cat’s eye works, simply and clearly.

The figure shows the schematic structure of the eye of a cat. Each element serves a specific purpose. Their functions and characteristic features determine the peculiarity of cat vision.

  1. Sclera. The outer shell that maintains the correct shape of the eye.
  2. Cornea (stratum corneum). Performs protective functions. It has a convex shape and protects the delicate iris and pupil from external damage.
  3. vascular layer. Without it, the functioning and nourishment of the eyes would be impossible. Yes, they also need nutrients and oxygen.
  4. lens. Many people imagine this organ in the form of a cut diamond. But in fact, it is a liquid substance. However, its functions are very similar to a real diamond. It also refracts and transforms the incoming light stream.
  5. Retina. Due to the presence of photoreceptors, this organ is responsible for the perception of the entire light flux that has passed through the cornea and lens. The first and very important feature of the cat’s vision lies precisely in this. The fact is that both in us and in our smaller brothers, photoreceptors are represented by cones and rods. Their ratio determines the sharpness and susceptibility of the eyes. So, in cats, the vast majority are rods (there are 25 times more of them than cones).
  6. tapetum. This is a special reflective layer that nature has endowed with felines. Thanks to him, they have such sharp eyesight and see well in the dark. Everything is simple here. In humans, only the retina captures the streams of light, but not all of them fall on it. In a cat, even those rays that have passed by the retina will be captured and reflected by this layer. This means that the brain will receive more information from the optic nerves.
  7. optic nerve. The information received by the retina and reflected from the tapetum is converted into electrical impulses that directly enter the brain and are processed there.

We did not list absolutely all the organs that make up the eye of a cat. The fact is that these main parts are directly related to our topic. Already on the basis of this information, it becomes clear that the eyesight of cats is unique, although in many ways similar to ours.

Features of vision

So, we have considered the components of the cat’s eye. Now it remains to draw conclusions and learn about the features.

  • Even with the naked eye it can be seen that the organs of vision of our pets are planted quite deeply. Therefore, it is more difficult for them to consider objects located on the periphery. The same feature explains the limited mobility of the eye itself.
  • The pupil is located vertically. Its size depends entirely on the lighting. The stronger it is, the narrower it is. In daylight, it completely turns into a narrow crack. The fact is that this number of light rays (which pass through it) will be enough to give complete information to the brain about the environment.
  • Direct exposure to sunlight is detrimental to the eyes. It’s all about their sensitivity. On average, it exceeds the human by 7 times.
  • Each eye has its own visual field. That is, the area around from which he reads information (receives a stream of light). The fields of the left and right eyes intersect. This explains the fact that cats see a three-dimensional image.
  • Our pets have color vision, although it is different from ours. They perfectly distinguish shades of the upper spectrum (blue, blue, green). But all shades of red they see in gray. The same applies to colors such as orange and yellow.
  • If it is easier for us to make out any object in statics, then for born hunters, the emphasis is shifted to moving objects. This feature becomes critical in the wild. That is why the cat will notice even the slightest stir or movement in the apartment.
  • Cats don’t have blind spots. Drivers are familiar with this concept. But some herbivores also have places that they simply cannot see. They are located directly in front of the muzzle of the animal. For hunters, this is unacceptable.

Causes of glow

At night, leaving the room and accidentally stumbling upon your pet, you can see how his eyes burn with bright lights. But contrary to such a common expression, their eyes do not glow. But how is it?

The thing is that a special layer, the tapetum, which we talked about earlier, is a mirror surface. Even the slightest stream of light falling on it is reflected. And we see exactly this reflected light.

Contrary to popular belief, even a cat with its unique vision cannot see in pitch darkness. In order for the brain to receive information, at least a weak source of light is needed. Many will object that they saw how the eyes of these animals flash in the dark. The fact is that those weak sources of light that exist in this darkness are not perceived by the human eye. It seems to us that the room is absolutely dark, but this amount is enough for the cat family.

Why is the color different?

Many may have noticed that in different breeds of cats, the retina has a different color. It really is. But this is not at all the main reason for the different glow.

The whole thing is again in the mirror layer on the back wall of the eye. With the same structure, this organ may have a different chemical composition and pigmentation. Due to this, shades from yellow to purple are obtained. Most often, we see green and yellow reflections.

Different colors are also explained by the structure of this layer. In some, it covers the entire back wall, while others have pigmented areas. And also the colors are refracted due to the layer, it is she who gives the green glow.

If you think that only our pets have such a unique feature, then you are mistaken. Look at your photos. Do they have an effect called “red eyes”. This is also nothing more than a reflection of light rays. And the red light is explained by the presence of vascular connections, which color the stream in a given shade.

How to explain to children?

Of course, it is much easier for adults to explain this or that scientific fact. But when a small child comes up to you and wonders why the cat’s eyes are glowing, then difficulties may arise. You will not tell the little fidget about the complex structure and refraction of light. It will be incomprehensible to him.

However, you don’t want to mislead the baby and say that this is the magical power that all cats are endowed with. After all, most of our beliefs are formed in childhood. What will be his surprise when they tell him about these features in the lessons of physics and biology.

There are two paths you can choose from here. The first is to tell the child a legend that is not without meaning and scientific justification. And she literally says the following. In ancient times, cats did not have such sharp eyesight. But since they only hunted at night, they simply needed to see in the dark. Then the good-natured goddess took pity and gave them the ability to collect even small rays of light. They gathered in the eyes of the cat and illuminated her path.

Despite the fabulous overtones, this legend has the right to exist. After all, by and large, everything happens just like that.

You can try to explain to the baby the glow of the cat’s eyes in a more prosaic way.. Take a small flashlight, go to the mirror and point it at the mirror. Let the baby see how the light is reflected and becomes visible. Further, we can say that your beloved cat has small mirrors hidden in its eyes, which also reflect light. Only she does not need to shine a flashlight in her eyes for this, even a faint moonlight will be enough.

It is worth noting that in Russia it was believed that dark forces peep at people through their eyes. Therefore, it was not recommended to look the cat in the eyes.

In Europe, during the Great Inquisition, these animals fell under even greater disfavor. They were considered servants of Satan and were mercilessly exterminated. The end of this story was sad, as the extermination led to an increased number of rats and mice and an epidemic of Bubonic plague.

Visually about the causes of glowing eyes in cats, see below.