"The laser projector may be mounted on an arm of a pair of eyeglasses and the camera may be mounted on an opposite arm of the eyeglasses. The processor may further be mounted on the eyeglasses and coupled to the laser projector and/or camera."
"A laser pattern for a virtual input device can be projected onto a hand of the user, and the user may use an opposite hand to select items of the virtual input device."
Wrote Google in its patent application, which was filed in June 2012.
Called "touch typing emulator for a flat surface," the product connects to a computer via USB and uses acoustic sensors to detect typing, but requires its users to be proficient in touch typing.