Look at a cat’s eyes and they look haunting and mysterious. Yet there’s actually a scientific reason why the eyes of cats look this way. The thin-slitted pupils of cats allow for a wider range of muscle movements and for more light to enter the eye.
By widening or narrowing the slits of their eyes, cats can let in more or less light, allowing them to hunt effectively at both night and day. For many cat owners, that usually means hunting socks, paperclips, and rubber bands, but at least cats can see them equally well in any form of light.