Cats see better than humans in semi-darkness, although they cannot see in complete darkness. Cats need only one-sixth of the amount of light that humans require to see.
For both humans and cats, the iris is the portion of the eye that expands to allow in more light when the area is dim. The iris of a cat opens fully to bring in more light in dark locations, and it has a reflective layer that makes better use of incoming light. While cats see well in dim light, their vision performs best on objects that are far away rather than those that are nearby.