3D televisions with active glasses work by shutting off each eye in rapid succession based on a pulse coming from the TV. Due to persistence of vision, each eye sees one continuous image, and they are collectively reconstructed in the brain into a 3D image. Take this application and modify it such that both eyes are shut off simultaneously according to a random pulse synchronized from the monitor. For each "on" pulse, display a random selection of pixels from across the entire image, and for each "off" pulse display garbage data. Over a short series of pulses, the entire image should be displayed during the time the display is "on". To an observer not wearing the appropriately keyed glasses, it would just look like snow, but to somebody with glasses that are timed to match the "on" pulses, the display would be perfectly clear.
In addition to enhancing privacy for personal displays, this could be used with wireless glasses to distribute information visually to a restricted group of people in a public space. While it's unlikely to provide much by way of actual security--somebody could probably record all the frames with a video camera and deduce which are the good ones after the fact--it would still be useful for situations where the information is only of significant value in the short term.-- ytk, Feb 04 2011 "Vizio Versus" - two players using one screen http://www.joystiq....gaming-on-one-scre/ [iaoth, Feb 04 2011] Yes!-- AntiQuark, Feb 04 2011 I read about something similar to this (too complicated to find) that was even cooler and more complex. A guy used eye tracking to follow the saccades (tiny rapid eye movements) of his eyes, and only show cleanly the actual part of the screen he was focussed on; the rest of the screen temporarily distorted. So anyone else would only see a distorted image, as their saccades wouldn't match the users. You can also remove the front polariser from your LCD screen, and wear (correctly) polarised glasses instead. Everyone else sees a blank screen.-- neutrinos_shadow, Feb 04 2011 Something similar exists: Vizio Versus. [link] It uses active shutter glasses to show relevant information to one player and hide it from the other.
In addition, I remember reading about something similar where they used an autostereoscopic screen combined with head tracking that essentially beams the image only in the direction of a single viewer. It could display different images for two viewers, even maintaining privacy if the viewers moved or switched places.-- iaoth, Feb 04 2011 random, halfbakery