YOUR NEXT PAIR OF READING GLASSES

For many people past the age of 40, focusing on close objects—restaurant menus, for instance—just gets harder and harder. Most people with this condition, called presbyopia, eventually give in and get reading glasses, bifocals or glasses with progressive lenses.
But what if there were another alternative that didn't require people to carry an extra set of glasses or have only part of their field of vision in focus at any one time? (More after the break)

Zoom Focus Eyewear LLC, of Van Nuys, Calif., has just such an option, and with it won this year's Silver Innovation Award. The solution: eyeglasses, called TruFocals, that the wearer can manually adjust to give clear, undistorted vision whether reading a book, working on a computer or looking into the distance. The judges praised the potential large-scale benefit of TruFocals. Richard S. Lang, one of the judges and a physician at the Cleveland Clinic, called the technology a paradigm shift in the way it addresses a problem "that has been handled the same way for many years." For more than 100 years, researchers have tried to come up with adjustable eyeglasses; a Baltimore inventor filed a patent on the idea in 1866. But a workable product that's easy to adjust, thin, lightweight and accurate proved elusive. Stephen Kurtin, a California inventor who previously devised one of the first word-processing programs, turned to the problem in the early 1990s. His solution, TruFocal eyeglasses, mimic the way that the lens of the human eye stretches and contracts to adjust focus. Each TruFocal lens is actually a set of two lenses: an outer lens, and an inner lens made of a flat glass plate attached to a flexible membrane that contains a clear, silicone-based liquid. A manual slider on the bridge of the eyeglasses adjusts the focus by changing the shape of the membrane. The outer lens can be custom made to correct other vision problems besides presbyopia, including nearsightedness and astigmatism. Once the TruFocal lenses are adjusted, the entire field of vision is in focus, unlike bifocals and progressive lenses, which keep only a limited area in sharp focus. So a user can adjust the glasses to focus only on the book he's reading, then look up and readjust them to focus solely on the TV across the room. There were some false starts along the way. Mr. Kurtin considered using liquid-crystal electronics to adjust the focus, but the batteries proved problematic. The first model weighed seven pounds. But after nearly 20 years of refinements, the first TruFocal glasses were introduced in 2009. There's a downside for the fashion conscious: The glasses come in one shape—round—and have been compared to the spectacles worn by Harry Potter. (They are sold in several colors, though.) The circular lenses are necessary to the workings of the technology; with any other shape, the flexible membrane couldn't keep a spherical shape when compressed. TruFocals aren't the only glasses with adjustable lenses. But other products are mainly designed for users in the developing world, where optometrists aren't widely available; they are meant to be adjusted once by the user to correct the focus at a given distance and then set that way. The Zoom Focus product is aimed at wearers who want to make constant adjustments in their vision. Next month, TruFocals will be rebranded as Superfocus glasses. The company will also change its name, to Superfocus LLC.