While we don't normally think of mirrors as toys, they are very useful for infant development -- and the provide baby with loads of entertainment as well. Imagine the excitement of seeing your own face for the very first time! In addition to countless hours of stimulating entertainment, mirrors provide infants with a sense of companionship as they wonder, "Who is this fabulous baby staring at me?"
Babies will spend more time on their bellies when looking at a mirror attached to the crib, and this is good for developing upper body strength as they push themselves up with their arms and hands. Mirrors also help the development of the eyes, as they require the infant to focus and track their own images in the mirror. Mirrors aid in social development, too, when your babies spends time making eye contact and trying out different faces (and reacting to those faces). Self-recognition is developed through use of mirrors, and with it self-knowledge.