By middle age, most of us need bifocals or reading glasses. It's an inevitable part of growing older; even people who've had perfect eyesight find their vision diminishing. Reading glasses are a clunky fix, because they clarify close vision while making faraway objects blurry.
Researchers at the University of Utah have developed a high-tech solution. They've built glasses with liquid lenses that automatically adjust their focus. Near or far, no matter where the wearer looks, the world will be clear.
Electrical and computer engineering professor Carlos Mastrangelo led the research along with doctoral student Nazmul Hasan. The idea derived from his own experience. "I have always had better than 20/20 vision for most of my young life," Mastrangelo says, "but when I reached my fifties I started squinting my eyes to see better. As I aged, the problem got worse and I eventually ended up needing reading glasses."
It's a different problem than near- or farsightedness. Our eyes contain an adjustable lens, called the crystalline. It shifts to bring objects into focus at different distances, depending where we're looking. But as we get older, Mastrangelo explains, the crystalline hardens and eye muscles weaken. Our eyes are less able to focus at different distances; we end up squinting, or fumbling with bifocals. It's called "age related accommodation loss."
The eyeglasses essentially do what middle-aged eyes can't: constantly adjust focus based on where the wearer is looking. A distance sensor in the glasses does the first part of the work, defining where the lens should be focused. The lenses themselves are filled with transparent fluid; small actuators on the edges deform the lenses to adjust the focus based on information from the distance sensor. And an app lets users upload their prescription so the glasses can react accordingly.
"Most people older than 45 (over 1 billion people worldwide) have some sort of accommodation-related vision problem and our glasses can correct the majority of them," Mastrangelo says. They wouldn't correct less-common problems such as cataracts or macular degeneration, but they would fix a widespread form of vision loss previously considered inevitable.
The Utah team has already built functional prototypes (they had to develop lightweight lenses and actuators first) and the state has helped them commercialized the technology with a new startup company called SharpEyes. In 12 months they aim to have a polished consumer product, with mass manufacturing to follow; they hope to have products ready on consumer shelves two to three years from now. If they're successful, we might never again watch somebody fumble for their reading glasses to look at a menu.