Cats' glowing eyes often spark intense emotions in their owners. Some experience both admiration for the greenish glow of a cat's gaze and fear at the sudden appearance of lights in the far corner of the room. When wondering why cats' eyes glow in the dark, people turn to both scientific knowledge and mystical experiences for an answer.
Scientific explanation
Cats have stereoscopic vision, allowing them to judge the distance to an object. About 60% are capable of eye movements, which cause their visual axes to converge and diverge. Cats have a visual field of 200°, compared to 180° in humans.
A special layer, the tapetum, is responsible for the function of reflecting light onto the retina.
Cats are animals adapted to a nocturnal lifestyle. Under these conditions, their visual organs must be able to detect even the faintest light. But nocturnal predators can also enhance this light thanks to a special reflective layer. It's located beneath the translucent photosensitive cells and reflects the light that passes through them.
The macula lutea (macular spot) of the cat's retina lacks a central fovea, but instead has a disc containing the cones. There are 25 times more rods in the retina than cones, so the ability to see in low light (which is the responsibility of the rods) is a priority for cats. This explains why cats are nocturnal predators.
The color of the glow depends on the pigmentation of the iris and individual characteristics. Typically, the eyes range from yellow to green. However, blue eyes often have a crimson-red tint.
Mysticism
A cat crossing someone's path from right to left is considered by Czechs to be a harbinger of good luck.
Cats were perceived as creatures capable of interacting not only with our human world, but also with the spirit world. When a cat peered out from the darkness, it was believed the light in its eyes was a reflection of another world. Therefore, it was advised not to look directly into their eyes: it's not worth looking that far.
In Rus', a domestic cat was expensive and could be a valuable gift, as it guaranteed protection of the harvest from rodents. It was also a symbol of peace and prosperity in the home, protecting it from evil spirits. Cats were also believed to have the ability to penetrate the other world and communicate with spirits.
A more frightening explanation was the close contact of cats with spirits, who could travel in cat bodies and, in the dark, look out and spy on people.
Whatever the convincing explanation for our beloved pets' glowing eyes, one thing is certain: cats dislike harsh light. Even from a camera flash.
Igor
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