Turn A Screw To Change Your Glasses

Adjustable eyeglasses are set to revolutionise the world of vision care.

Here’s a head-turning, new look at eyeglasses. No more rushing off to the optician for a new pair when the lens power changes. Simply readjust to the new power needs of your eyes by turning screws on the side. Much like you use and share binoculars, and adjust the focus by turning a screw in the middle, the adjustable eyeglasses will revolutionise vision care since the first pair of glasses were made in Italy more than 800 years ago. In case your eyeglasses break or you forget them at home, you will be able to buy a new pair from a neighbourhood store.

Oxford, UK-based Adlens, the company researching and marketing the adjustable eyeglasses technology sees this as an affordable option, to begin with, in situations of emergencies like earthquakes. “It’s an instant replacement for your eyeglasses and can be shared with anyone in need,” says Adlens co-founder and director James Chen. Adlens was funded in 2005 by American private equity player Warburg Pincus, which sold its stake to Aspex Eyewear Group of Canada for an undisclosed sum two years later. The company has a 20-people research team based out of Oxford, focused on the adjustable lens technology. As the glasses target emergency use at present, the company calls them ‘EmergenSee’. The Adlens EmergenSee are continuously adjustable eyeglasses that correct near and far vision. Users determine their own lens power with the turn of a dial. “EmergenSee can be used for distribution during disaster relief to increase safety and well-being of victims,” says Chen. Because the power can be continually adjusted, these eyeglasses can be shared among families, or used for medical conditions where temporary fluctuating vision exists. The power can be adjusted within a wide band, from –6 to +3, covering 90 per cent of the population using eyeglasses. Interestingly, the underlying technology that the glasses work on dates back to 1968. The eyeglasses employ Alvarez lenses, a type of variable power lens invented by 1968 Nobel Prize-winning physicist Luis Alvarez. Each lens comprises two movable parts that change the lens power when combined and moved over each other. The mechanism used to move the Alvarez lenses parts was invented and patented by the VU University in Amsterdam and the EmergenSee was developed by Adlens in conjunction with Professor Rob van der Heijde from the University. “It has been in the labs for the past 11 years and is now ready for commercial use.”

Adlens has developed two types of lenses — one that comprises a pair of movable lenses, adjusted by a screw, and the other, to be launched in the Japanese market on December 9, filled with silicon oil. The lenses use refraction or bending of light as it moves from one medium to another. For example, light rays bend when they travel from air to glass to liquid. By moving screws on the sides of the frame, users can pump in or take out oil, and adjust the level of silicon oil in the lens and focus the lens to their needs. However, the former can be adjusted any number of times and the latter only once, as the screws on the side are too large, like small horns on the sides and not aesthetically pleasing. Once adjusted, the screws can be removed.
Says Chen, “Eyeglasses fall in the category of class one medical devices (devices with lowest risk to life and subject to least regulatory control), hence do not need extensive medical testing. However, we recommend them for emergency use at present. As technology improves, the use will only expand.” Adlens is working towards electronicallycontrolled eyeglasses, which will do away with the need to manually turn screws. This is likely by the end of 2012.

Sagar Bhargava, specialist in cataract, glaucoma and refractive surgery Sankara Nethralaya says such eyeglasses may be viable but need to be tested. “Adjustable eyeglasses may not be practical for longterm use as there are too many variations with vision,” he adds, “Also, those with spherical eye defects will be more easily able to use them then those with cylindrical power (differently curved cornea) defects. People can try it as glasses are not harmful to eyes – users discontinue or see a doctor in case of any discomfort.”
EmergenSee does not provide cylindrical power and will be useful for those with spherical defects, that is about 60% of the eyeglasses using population. For those in the seven to 21 years age group using glasses, the power changes more frequently – almost every year. In the 40-60 year age group, the power of reading glasses changes every two or three years. “On average, power might change by 0.5 to .75 every six months. Progressive lenses are already there and they meet the need of changing vision. Though technology that offers variable lenses sounds interesting, users will still need to see specialists for specific needs,” says Bhargava.

The adjustable lenses are undergoing pilots in 15 developing countries. Back in 2006, Arvind Eye Hospital in Chennai did pilots on early prototypes but discontinued as they didn’t find them aesthetically perfect. In April 2011, Japan became the first country to market EmergenSee glasses. Priced $62, they are being sold via optical stores, the Internet and department stores – and are being promoted as quick alternatives for people who may have lost, forgotten or broken their glasses.