The PS2 EyeToy was designed specifically for the PlayStation 2 console. It uses a different technology and communication protocol than the PS3 Eye camera, which was released later.
While you can use a PS2 EyeToy on a PS3, it will only work with PS2 games that support it.
If you are looking for a camera to use with PS3 games, you need the PS3 Eye camera, also known as the PlayStation Eye.