Why do cats glow in the dark?

Cats are amazing and unique animals. It was not for nothing that they were especially treated in different cultures. Some considered them sacred animals, others attributed to the servants of 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 at least some mystery in this.

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

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

1. Sclera. Outer sheath that maintains the correct shape of the eye.
2. Cornea (stratum corneum). It performs protective functions. It has a convex shape and protects the delicate iris and pupil from external damage.
3. The vascular layer. Without it, the functioning and nutrition of the eyes would have been impossible. Yes, they also need nutrients and oxygen.
4. Lens. Many represent this organ in the form of a faceted diamond. But actually it is a liquid substance. However, its functions are very similar to a real diamond. It also refracts and transforms the incoming stream of light.
5. Retina. Due to the presence of photoreceptors, this organ is responsible for the perception of the entire luminous flux that passes 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 our and our smaller brothers have photoreceptors represented by cones and rods. Their ratio determines the sharpness and sensitivity of the eyes. So, in cats the vast majority are sticks (they are 25 times more than cones).
6. Tapetum. This is a special reflective layer that nature has bestowed upon cats. Thanks to him, they have such sharp eyesight and can see well in the dark. Everything is simple here. In humans, only the retina catches streams of light, but not all of them fall on it. In a cat, even those rays that passed by the retina will be captured and reflected by this layer. So, the brain will receive more information from the optic nerves.
7. Optic nerve. Information obtained by the retina and reflected from the tapetum is converted into electrical impulses that directly enter the brain and are processed there.

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

• Even with the naked eye it is clear that the organs of vision of our pets are set 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 is completely dependent on lighting. The stronger it is, the narrower it is. In daylight, it completely turns into a narrow crack. The fact is that even this number of rays of light (which pass through it) will be enough to give complete information to the brain about the environment.
• Direct sunlight will adversely affect your eyes. It's all about their hypersensitivity. On average, it exceeds human by 7 times.
• Each eye has its own visual field. That is, the area around 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 the shades of the upper spectrum (blue, blue, green). But all the shades of red they see in gray. The same applies to colors such as orange and yellow.
• If it’s easier for us to discern any subject 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 stirring or movement in the apartment.
• The cat has no blind spots. Drivers are well acquainted with this concept. But some herbivores have places that they simply don’t see. They are located directly in front of the animal's face. For hunters, this is unacceptable.

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

The thing is that a special layer, the tapetum, which we spoke about earlier, is a mirror surface. Even the smallest stream of light falling on him is reflected. And we see precisely 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 light source is needed. Many will object that they saw how the eyes of these animals flash in the dark. The fact is that those weak light sources that are in this darkness are not perceived by the human eye. It seems to us that the room is completely dark, but this amount is enough for the cat family.

Many could notice that in different breeds of cats, the retina of the eye has a different color. This is indeed so. But this is not at all the main reason for the different glow.

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

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

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

However, one does not want to mislead the baby and say that this is the magic power that all cats are endowed with. After all, most of our beliefs are formed precisely in childhood. What will be his surprise when at the lessons of physics and biology he will be told about these features.

Here you can choose for yourself two ways. The first is to tell the child a legend that is not without meaning and scientific justification. And it reads literally the following. In ancient times, cats did not have such a sharp vision. But since they hunted only 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 lit her way.

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

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, you 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.

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

See more about the causes of eye glow in cats.