A signal from the TV tells each side of the glasses when to turn on and off, showing each eye slightly different images that create the sense of depth.

VOA: special.2010.01.26

"Someone could attack the industrial control systems that control all the valves, all the distribution systems, and are used to turn on and off various aspects involved with energy and the electrical power grid and oil and gas distribution networks,".

VOA: standard.2009.08.11