Benjamin Franklin would be proud. The tinkerer who loved playing with electricity and allegedly invented the bifocals might have been glad to know that one company has now brought the two things together: PixelOptics has designed a pair of powered specs that can track users’ eyes and automatically adjust the glasses’ focal length, depending on if the wearer needs to see close-up or far-away.

The glasses use liquid crystals, which can change how much they bend light when an electrical current runs through them. A video demonstration of what a wearer might see is available on PixelOptics’ website, and the company hopes that the glasses will be available in the United States before the end of 2010.

Peter Zieman, director of European sales for PixelOptics, said the device uses motion tracking software similar to the iPhone, and told The Telegraph:

“In essence, glasses haven’t changed all that much since they were first invented. The most recent development was transition lenses that tint in sunlight, but even that was 15 years ago…. Our glasses bring modern technology to an old solution.”

Perhaps Zieman doesn’t give other eye-wear inventors enough credit; for example, in 2008 a retired physics professor Josh Silver created a pair of fluid-filled spectacles that could change strength when the amount of liquid inside varied.

Still, as Star Trek fans might agree, electric eyeglasses really are more futuristic.

Related content:
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Discoblog: Possible Cure For Blindness: Implanting a Telescope in Your Eye

Image: flickr / Franklin College