The reason why a cat’s eyes become thinner and rounder is because it absorbs light. Generally, in the morning when there is not enough sunlight, the cat’s pupils will become jujube-like, and at noon when there is sufficient sunlight, the cat’s pupils will become like jujubes. It becomes a line, and at night when the sunlight is almost gone, its pupils will turn into a full moon shape.

Tips:

Although cats have strong night vision, they will not be able to see if there is no trace of light, and cats’ eyes are myopic. Can't tell the distance is too far.