A new “smart” contact lens is designed and developed by a team from the Shenzhen Institutes of Advanced Technology (SIAT) at the Chinese Academy of Sciences. The prototype lens is made of a biocompatible hydrogel which is in turn composed of a polymer known as poly(2-hydroxyethyl methacrylate), or pHEMA for short.
The polymer’s nanostructure changes in reaction to moisture levels by changing color.
As humans age, they gradually lose the ability to accommodate, or refocus, to near distances because of the stiffening of the crystalline lens. This condition, known as presbyopia, affects nearly 20% of people worldwide. We design and build a new presbyopia correction, autofocals, to externally mimic the natural accommodation response, combining eye tracker and depth sensor data to automatically drive focus-tunable lenses. We evaluated 19 users on visual acuity, contrast sensitivity, and a refocusing task. Autofocals exhibit better visual acuity when compared to monovision and progressive lenses while maintaining similar contrast sensitivity. On the refocusing task, autofocals are faster and, compared to progressives, also significantly more accurate. In a separate study, a majority of 23 of 37 users ranked autofocals as the best correction in terms of ease of refocusing. This work demonstrates the superiority of autofocals over current forms of presbyopia correction and could affect the lives of millions.
Whether we’re reading articles or emails or tweets, most of us probably spend more time reading online than paging through physical books. If you wear glasses, there’s a good chance you’re putting them on to stare at a screen. But what if a digital display could take care of vision correction on its own?
New technology under development at the University of California-Berkeley and MIT automatically corrects people’s vision defects without glasses. Plug a glasses prescription into the new software, and the system calculates how to display the image so it won’t look blurry. Basically, by adjusting the light from each pixel on a device and then passing it through a tiny mesh attached to a monitor or phone screen, the system personalizes the image so it’s crystal clear.
If you’re farsighted, the display would mean you wouldn’t have to lean inches away from a computer, or struggle to find glasses when a smartphone buzzes late at night. In a car, the technology could be used to display navigation or other information on a dashboard. The display could also be useful for people who wear glasses to see at a distance, since those glasses make it hard to see up close (picture your grandmother peering over her spectacles).
The technology has several other obvious potential uses. “Kindles and e-readers could be a great application for people who need reading glasses,” says Brian Barsky, who is leading the research at UC Berkeley. “Currently, the text can be magnified, but that is a rather basic approach. It’s as if we are putting the eyeglasses on the display.”
While most people would probably use this type of display just to avoid the inconvenience of wearing glasses or contacts–or the potential risks of laser surgery–for some, it could actually be the only option to see clearly.
“There are some optical defects which cannot be corrected with eyeglasses,” says Barsky. “People whose eyes have these problems do not have many options.” For the millions of people who have these more unusual eye defects, the new displays could actually be life-changing.
“We’re living in a world where everyone is expected to be looking at display devices, such as phones and computers,” says Barsky. “This is the case not only for workers who have office jobs. Even construction workers now use rugged tablets. People who are unable to view displays are at a disadvantage in the workplace as well as in other aspects of their lives.”
In developing countries, where glasses can be expensive but digital devices are still common, the technology might help create new opportunities for education and jobs. The researchers are working on developing the proof of concept now.
Researchers at Tohoku University have developed a new type of smart contact lenses that can prevent dry eyes. The self-moisturising system, which is described in the journal Advanced Materials Technologies, maintains a layer of fluid between the contact lens and the eye using a novel mechanism. To know more…