A team of researchers at the University of Arizona collaborating with PixelOptics Inc. has created such eyeglass lenses, claiming that the developing procedures involve applying differing electric voltages to a thin sheet of liquid crystals placed between two layers of glass.
This technology allows the one wearing such lenses to immediately focus on objects placed within distances ranging from close to far, thus eliminating related problems that tend to appear with the human aging process.
Even if, for the time being, a special trigger is needed to switch the focal distances, study author Guoqiang Li says that "it is possible to put in a rangefinder and automatically focus the lens", which is probably the next step researchers will be doing.
The technology used by new lenses designed as a "series of concentric rings of tiny, transparent electrodes" seems indeed very promising, compared to the cumbersome use of bifocal glasses owned by the large majority of people with sight problems.
"The field of view is limited in such bifocal eyeglasses, requiring the user to gaze down to accomplish near visions tasks and in some cases causing dizziness and discomfort," Li explained. "In stimulated and actual human vision tests, the new lens performed well at both near and far focusing tasks. These results represent a significant advance in vision care."
"When it's on it has focusing power that can be used for reading. When it's off, it has no focusing power - it's just like a piece of glass - and can be used for driving and seeing far off things", Li added.
However, there seem to be other sorts of inconvenients with the new lenses.
"The problem is that liquid crystal is quite heavy and expensive. Because it is heavy it means thick frames have to be used and people often choose glasses partly because of the style so I cannot see these glasses replacing bifocal and varifocal", noted Professor Mike Boulton, Cardiff University optometry expert.
