Alice White
Since time immemorial, people have developed a special relationship with cats. In many cultures, they are considered mystical creatures. These animals have many inexplicable, mysterious qualities. One of them is the glow of the eyes in the dark. This factor was the reason for the assignment of witchcraft to cats. Many pet owners would like to know what is the secret of this phenomenon.
The phenomenon of glowing eyes in other representatives of the fauna
Many consider the glow of the eyes to be the prerogative of cats, their individual phenomenon. But this is a delusion. The effect is observed in all representatives of the fauna, the visual organs of which are equipped with a layer of the tapetum. It is found in:
- wild, large felines;
- dogs;
- deer and horses;
- rabbits;
- rats and mice;
- spiders;
- crustaceans and fish.
The difference between the glow of a cat’s eyes is its expressiveness, showiness, which makes it more noticeable and attractive. In addition, we see these animals in the dark most often, which was the reason for attributing this phenomenon to our beloved pets. 
Human eyes do not have a tapetum, they do not have a reflective effect, they do not glow in the dark. Indeed, according to the laws of nature, people are awake during daylight hours. This effect is gifted only to predators and animals that must escape from these nocturnal hunters.
Interesting information about the peculiarities of the cat’s vision
In most cases, the eyes of cats glow with green, yellow light. Intensity, shade is determined by the amount of zinc, riboflavin in the tapetum layer. There are also rare glow colours. For example, the eyes of Siamese cats emit red, crimson light in the dark. The decrease in the brightness of the effect comes with age. In older cats, the density of the lens increases, which reduces the ability to reflect photons. Glaucoma and cataracts can cause dullness in young cats.
Cat eyes have several unique features:
- The visual acuity of these pets is almost 10 times higher than that of humans.
- The viewing angle of cats is 20 ° greater than that of humans. Our radius is 180 °, for pets, it is 200 °.
- In terms of colour perception, cat eyes are inferior to human eyes. Animals can distinguish only a few shades. They see well the tones of green, black, blue, white, grayscale. They do not perceive the rest of the sectors of the colour spectrum. Cats were previously thought to see the world in black and white, but recent research refutes this claim. Do not think that limited colour perception is uncomfortable for cats. Pets are not worried about the fact that they cannot distinguish between yellow and red, they don’t need it.
The quality of vision of these animals can be appreciated by two facts. A cat can see objects at a distance of half a kilometre or more. She can clearly see the smallest details of the object at a distance of 60 meters. The most keen-sighted person does not have such qualities. 
There are some differences in the perception of static and moving objects. Animals have a better view of the moving object. And most clearly they see objects moving horizontally. The cat sees less vertically moving objects.
It is known that dogs are better at seeing nearby objects; with distance, vigilance decreases. In cats, the organs of vision are arranged differently. These pets are short-sighted. They have a poor vision of objects located nearby, but they perfectly see a distant target.
