Nintendo has filed a patent with the US Patent Office for an eye-tracking device that will allow for 3D viewing on a standard 2D display.
The device works by having the user wear glasses - possibly with the focus on mounted sensors as opposed to special lenses - and a camera which is placed by the TV. The user's head movement is then tracked by the camera to give the illusion that displayed objects exist in a three-dimensional space and provide a sense of depth to the image.
Strangely, notations in the patent also explore other possibilities for an immersive gaming experience, including the sense of smell and temperature control.
Whether or not Nintendo follows through on these filings is anybody's guess, but a form of head-tracking could provide a relatively inexpensive way for people, even with monocular vision, to experience a sufficient 3D effect on any type of TV.