Far-sighted researchers envision autofocus eyeglasses
From: EDN - 04/27/2006 - page 32
By: Matthew Miller

Scientists from the University of Arizona and the Georgia Institute of
Technology are working to eliminate traditional bifocals by developing
eyeglasses that can automatically refocus. The lenses in the team's prototype
feature liquid-crystal material sandwiched between two flat sheets of glass.
A transparent coating of ITO (indium-tin oxide), which researchers apply by
photolithography in a circular pattern over the lenses, acts as an electrode.
By applying a voltage as low as 1.8V, the researchers change the orientation
of the liquid crystals, thus altering the focal length of the lenses. 

The prototype changes focus by switching on and off, but the researchers
claim that the advance will lead to active eyeglasses that automatically
adjust their focus based on the position of the wearer's eyes. Tests with
human subjects confirm that the prototype lenses improve close-up vision when
switched on and do not impair long-distance vision when switched off. Pixel
Optics has purchased patent licenses to develop the technology commercially. 

Caption:
The liquid-crystal lenses in this prototype pair of eyeglasses can alter their
focal length in response to a voltage.

Read the entire article at:
http://www.edn.com/article/CA6325606.html?ref=nbra&text=autofocus

Links:
University of Arizona
http://www.arizona.edu/

Georgia Institute of Technology
http://www.gatech.edu/

Pixel Optics
http://www.pixeloptics.com/