Not Your Father's Bifocals

Future glasses could use liquid crystals to switch from close- to long-range viewing at the touch of a button.

By Jessica Ruvinsky|Saturday, July 01, 2006
RELATED TAGS: GADGETS, AGING, SENSES
bifocals
bifocals
Next-generation bifocals get rid of double lenses. Instead, they use tiny electric voltages and a layer of liquid crystals.
Courtesy of Lori Stiles, University of Arizona

"Nobody in their right mind would wear these glasses," says Nasser Peyghambarian, one of the inventors, referring to the hideous prototype pictured above right. But then aesthetics isn't Peyghambarian's department. An optical scientist at the University of Arizona, he and a colleague have come up with a new approach to bifocal spectacles that may one day revolutionize the way people past a certain age look at menus in restaurants. Rather than juxtaposing two different lens strengths in a single frame, Peyghambarian's device has special lenses that switch from close- to long-range viewing at the touch of a button.

The secret is an ultrathin liquid-crystal layer sandwiched between two layers of glass. When an electric current is turned on, the liquid-crystal molecules rotate, thus bending the incoming light like a lens. Future iterations will focus automatically like a camera, rather than requiring wearers to press a button, and with any luck they won't require a head strap.
cactusfuzzy
cactusfuzzy
cactussharp2
cactussharp2
Examples of vision before and after the next-generation bifocals.
Comment on this article
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

ADVERTISEMENT
ADVERTISEMENT
Collapse bottom bar
DSC-JanFeb15
+

Log in to your account

X
Email address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it emailed to you.

Not registered yet?

Register now for FREE. It takes only a few seconds to complete. Register now »