For those of us who have ever needed glasses or contact lenses, it's hard to forget the moment you see clearly again for the first time. The world opens back up as the details of faces and flowers, signs and movie screens return to focus.
Odds are, there will be many more of these moments for many, many more people, as Stanford engineers refine a new invention that promises to correct age-related far-sightedness more effectively than progressive lenses.
In a paper published today in Science Advances, electrical engineer Gordon Wetzstein, PhD, and members of his lab describe the technology behind the prototype "autofocal" glasses. As the news release explains,
The Stanford prototype works much like the lens of the eye, with fluid-filled lenses that bulge and thin as the field of vision changes. It also includes eye-tracking sensors that triangulate where a person is looking and determine the precise distance to the object of interest. The team did not invent these lenses or eye-trackers, but they did develop the software system that harnesses this eye-tracking data to keep the fluid-filled lenses in constant and perfect focus.
This is an improvement on progressive lenses, which filter a person's line of vision through different prescriptions depending on where they look. That can make it difficult to walk down stairs, for example, because the lens has been treated to magnify something closer, like a book, when the wearer is looking down at that angle. As graduate student Robert Konrad, a co-author on the paper, notes, "People wearing progressive lenses have a higher risk of falling and injuring themselves."
In contrast, in a test of 56 people with the presbyopia vision defect (trouble seeing close), wearers said they were able to focus their vision better and faster while reading and doing other tasks using the autofocals compared with progressive lenses, according to the news release. Wearers "also tended to prefer the autofocal glasses to the experience of progressive lenses," the release said.
One thing that may not be preferred is the current look of the autofocal glasses. They deploy technology similar to that used in virtual reality systems, and correspondingly, the prototype resembles the bulkier, heavier VR goggles -- but perhaps not for long. According to the news release:
The next step will be to downsize the technology. Wetzstein thinks it may take a few years to develop autofocal glasses that are lightweight, energy efficient and stylish. But he is convinced that autofocals are the future of vision correction.
'This technology could affect billions of people's lives in a meaningful way that most techno-gadgets never will,' he said.
I, for one, can't wait.
Photo by Skitterphoto