Apple patent from 2010 tracks your eyes to give 3D illusion on screen
The problem with mobile 3D is that so far it has required the manufacturer to use a stereoscopic screen that can make one dizzy if viewed for too long of a period, or at the wrong angle. According to Patently Apple, the Cupertino based tech firm has patented a different technique for 3D imaging that does not require a stereoscopic display. The technology uses features found on most smartphones like the accelerometer, GPS, compass, and gyrometer to come up with a precise point in space for the phone. Using the front-facing camera to track your eyes, the data is all jumbled together to present a 3D representation of what is on your screen. An app called i3D in the App Store uses a similar approach although not nearly as sophisticated as Apple's technique.
Apple's patent details how the UI of the mobile device can be used to enhance the illusion. For example, the drop shadows used on iOS icons can be adjusted and moved longer or shorter in real time to give the appearance of 3D. According to the patent, the 3D images can be "turned on" or activated with a gesture. While there was speculation last year that 3D imaging was a dead certainty for the Apple iPad 3, that report might be at least one year early. There could be demand for 3D support for some map functions and for some games, but for now, Apple will probably want to give this more time to perfect it and to gauge the demand.
source: PatentlyApple via Geek.com