Vision Command was an extension to the Lego MindStorms range of robotic education kits.

It includes a USB camera (Logitech house in lego moulds) and some visual recognition programming software - which works in a similar way to the software that comes with the Lego RCX.

Using this with the RCX meant you could give visual processing abilities to robots, but the significant trade-off is tethering the robot with a USB umbilical to the computer.