What will it take to help a child in a poverty-stricken area to see the world more clearly? According to the U.K.-based Centre for Vision in the Developing World (CVDW), it takes some ingenious manipulation of plastics and polymers.Â In collaboration with Dow Corning, CVDW has designed cheap plastic glasses for which the wearer can adjust the lens power to his or her satisfaction with a polymer.
The plastic glasses come with syringes filled with silicone fluid. (Dow Corning is a global leader in silicone technology.) Silicones are synthetic polymers that have diverse applications, such as lubricants, medical devices, and insulation. In the CDVW glasses, the material is pumped into the lenses by the wearer to control the lens power.
The glasses comprise tough polycarbonate lenses which each contain a silicone filled membrane. Each membrane is connected to a small syringe on each arm of the eyewear. All the user has to do to create their own prescription glasses is control a dial on each syringe which increases or reduces the amount of silicone fluid in the membranes, altering the power of each lens. Once the wearer is satisfied with the settings, the membrane can be sealed and the syringes removed.
Josh Silver, a physicist at the University of Oxford and director of CVDW, invented the fluid-filled, adjustable eyeglasses in the 1990s. Today, more than 30,000 pairs of the glasses have been distributed to adults in several developing nations; CDVW is currently working on glasses that children can use. The glasses cost about $20 a pair, but the organization is aiming to get the cost down to about a dollar.
You can watch the glasses in action in the video from Dow Corning, embedded below.
Source:Â “Seeing clearly with silicone,” Chemistry World, 03/21/11
Source:Â “Inventor’s 2020 vision: to help 1bn of the world’s poorest see better,” The Guardian, 12/28/08
Image by williamcho, used under its Creative Commons license.
Rajendrani "Raj" Mukhopadhyay is a science writer and editor who contributes news stories and feature articles on scientific advances to a variety of magazines. Raj holds Ph.D. in biophysics from Johns Hopkins University.