It’s bad enough having vision problems, but having to carry multiple pairs of glasses or use awkward bifocals just adds insult to injury. An electrical engineer decided that there had to be a better answer, and he set about proactively finding a solution.
Worldwide, more than a billion people suffer from the vision problem presbyopia – an age-related condition which leads to loss of focal accommodation, causing difficulty reading at arm’s length. Bifocal glasses – the ones librarians wear, with different lenses at the top and bottom of the frame – are usually prescribed to cope with this, but if a sufferer also has near or far-sightedness, they may require more than one pair of everyday goggles.
Carlos Mastrangelo, a professor of electrical engineering at the University of Utah, was frustrated that he needed a separate pair of reading glasses, so he and his team created a pair of specs that adjust themselves for any setting.
These tunable specs – which can be programmed with your prescription through a smartphone app, and updated as your prescription changes – can actually tell where you’re looking and adjust the focal correction for that distance.
While tunable lenses are already being used in various situations, such as microscopes, it’s hard to make them thin enough and low-power enough that people can wear them on their faces without looking like a speccy no mates. Indeed, the prototype produced by Mastralengo is still pretty clunky, though he’s confident he can get it sleeker.
These glasses are based on an infrared distance-meter built into the frames, which bounces infrared off objects to determine how far away they are. The glasses then adjust to the appropriate correction in just 14 milliseconds.
Put simply, each lens is a chamber with elastic walls, filled with glycerin. The shape of the chamber is changed – either thicker at the top or thicker at the bottom – when it is squeezed by a transparent piston, which is driven by the distance sensor.
The glasses are powered with a rechargeable battery, which Mastrangelo says should last 24 hours. The high speed of the adjustment uses a lot of power, but when it’s not adjusting, the power use is nearly nil.
Since you’ll only need one pair of specs for any distance viewing and you won’t need to replace them as your prescription changes, we can’t imagine the eyeglass industry will be all that happy about this development. And librarians are going to need a new accessory.