51¶¯Âþ

Self-focusing spectacles are on the horizon, doing away with the need for
bifocal or progressive lenses. Universal Ventures of the Cayman Islands is
developing variable focus glasses that measure the distance to the object you
are looking at (EP 837 603). The trick is to use triangulation: infrared light
from an LED inside the frames is bounced off the wearer’s eyes to detect their
direction of gaze. By measuring the angle at which the eyes converge, the system
calculates the distance to the object the wearer is looking at. It then adjusts
the lenses accordingly.