Cats can distinguish the shape and movement of objects with only 1/6 of the light required for humans to see things. The extra curvature on the front of the cat's large eyes can maximize the amount of light they receive. , and the reflective transparent layer behind the eye acts as a mirror, reflecting any unabsorbed light back to the retina, and this layer of light-sensitive membranous tissue receives the image.

A cat’s lens is more elastic than a human’s, so when the light is too strong at noon, the cat will shrink its pupil to prevent more light from entering, and when the light is weak, it will dilate the pupil to accept more light. The cat's pupils do not change shape with the position of the sun, but adjust the size of the pupils according to the intensity of the light.