Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UA Optical Scientists Develop Switchable Focus Eyeglass Lenses

04.04.2006


Optical scientists have developed eyeglass lenses that switch focus in a blink of an eye.

Optical scientists at The University of Arizona have developed new switchable, flat, liquid crystal diffractive lenses that can adaptively change their focusing power. That’s great news for those old enough to wear bifocals. And it’s great news for anyone with imperfect vision, for it opens the way for next-generation "smart" eyeglasses -- glasses with built-in automatic focus.

In the foreseeable future, for example, you won’t change prescription eyeglasses -- your eye doctor will just tweak a new prescription into the specs you already own. You could even program your glasses for better than 20-20 vision. "Right now, in our prototype, you switch the lenses on or off to change focus," said Nasser Peyghambarian, chair of photonics and lasers in UA’s College of Optical Sciences and professor of optical sciences, materials science and engineering. "But ultimately this will act just like your automatic camera: Eyeglass lenses will know where to focus just like your auto-focusing camera does."

Peyghambarian is part of the team that began developing the focus-changing lenses in 2001 under an agreement between the university and private industry. The UA licensed three patents from the work to the Johnson and Johnson Development Corp., which sponsored the research. A firm called Pixel Optics has since purchased the patent licenses from Johnson and Johnson to commercialize the innovative technology.

Ten UA scientists and two colleagues now at the Georgia Institute of Technology are publishing their first science paper about the switchable-focus lenses this week in an article online at the Proceedings of the National Academy of Sciences website, http://www.pnas.org/current/shtml. The novel lenses focus electroactively, said Guoqiang Li, UA optical sciences assistant research professor and lead author on the scientific paper.

They are basically two pieces of flat glass spaced five microns apart. Five microns is an incredibly small space -- roughly one-twentieth the diameter of a human hair. The space is filled with liquid crystal -- the same kind of stuff in your laptop’s liquid crystal display. The flat glass is coated with an even thinner layer (one-tenth micron) of indium tin oxide, or ITO, which is a transparent electrode. Unlike electrodes made of aluminum or gold, ITO transmits most of the light that hits it. The transparent electrodes are patterned in a circular array over the area of the lens. The circular pattern is created through photolithography, an extremely precise technique that processes with light and chemicals.

Applying less than two volts to the circuit changes the orientation of the liquid crystal molecules, and that changes the optical path length through the lens. It takes only about 1.8 volts to change the index of refraction so that light refocuses, Peyghambarian and Li explained. The result is a flat piece of glass that acts like a lens. The scientists first tested the imaging properties of the lens on a model human eye, then built prototype eyeglasses that real humans tested. The clinical results agreed with the model eye test. Their tests showed that distance vision was no way impaired when the glasses were switched off and enabled close-up vision when switched on. Prototype switchable focus glasses developed at the University of Arizona. Industry will commercialize a more attractive version.

"We have demonstrated switchable liquid crystal diffractive lenses with high diffraction efficiency, high optical quality, rapid response time, and diffraction limited performance," they reported in the PNAS article. "These flat lenses are highly promising to replace conventional area division refractive, multi-focal spectacle lenses used by presbyopes," they wrote. Estimates are that 93 percent of the world’s population over age 45 have the condition called "presbyopia," where an aging person’s eye lens loses flexibility and therefore, its ability to shift focus from distant to near objects. Presbyopes will be some of the first to benefit from the UA research.

Electroactively focusing eyeglasses will revolutionize the $50 billion worldwide vision care industry, backers said at the outset of the UA research project. Their major step in creating state-of-the-art liquid crystal diffractive lenses will have applications beyond vision care, the scientists predict. Tools with switchable lens elements would be valuable in dentistry, for example. "It’s great to see our new concept materialize and be validated after all these years of continuous efforts," said Bernard Kippelen. Kippelen, who helped start the project when he was at the UA, is now a professor of electrical and computer engineering at Georgia Tech. "People don’t often recognize that university scientists make prototypes," Peyghambarin said. "People think of us as just generating science papers. But when we actually make something like this, in house, people begin to realize we have real expertise that’s applicable to everyday problems."

In addition to Li and Peyghambarian, UA optical scientists who collaborated in the research are David L. Mathine, Pouria Valley, Pekka Ayras, M. S. Giridhar, Gregory Williby, James Schwiegerling (who also is on the faculty in UA’s department of ophthalmology and vision sciences), Gerald R. Meredith, and Seppo Honkanen. Bernard Kippelen and Joshua N. Haddock of the Georgia Institute Technology also collaborated.

Lori Stiles | University of Arizona
Further information:
http://www.optics.arizona.edu

More articles from Medical Engineering:

nachricht New technique makes brain scans better
22.06.2017 | Massachusetts Institute of Technology

nachricht New technology enables effective simultaneous testing for multiple blood-borne pathogens
13.06.2017 | Elsevier

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Touch Displays WAY-AX and WAY-DX by WayCon

27.06.2017 | Power and Electrical Engineering

Drones that drive

27.06.2017 | Information Technology

Ultra-compact phase modulators based on graphene plasmons

27.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>