The system uses a camera and viewing system built into a pair of glasses. As you bring your hand towards your mouth, the camera captures an image and after processing it on an attached computer, plays the image back through the glasses. Your hand is kept at its normal size but the computer is able to alter the size of the forkful you are about to eat tricking you brain into thinking your eating more than you are.
Researchers found calorie intake was reduced significantly using the system.
On the same topic there once was a lower tech version where a pair of glasses was designed with a rather ugly blue tint. The aim was to help you eat less by making food an unappetising blue hue!
Before you ask, neither is available at Cameron Optometry…yet.