Joshua Silver, a professor of physics at the University of Oxford, invented adaptive spectacles, or “adspecs,” as a way to bring vision correction to the half of the world’s population that currently needs glasses but does not have access to an optometrist. He wants to see a billion people having vision correction by 2020.

James Geary | November 2009 issue
Why do so few people in the developing world have access to glasses?
“In the developed world, some 60 percent of the population wears corrective eyewear. So you would expect that over half of any population would need corrective eyewear. But in many countries in the developing world, only a few percent of people wear glasses because the delivery of glasses depends on trained professionals and advanced infrastructure. In the developing world, there are too few professionals and the infrastructure is poor. In the U.K., there is about one optometrist for every 10,000 people. In some parts of sub-Saharan Africa, there is one optometrist for every eight million people.”
What’s the solution?
“People can make their own glasses. Using adaptive lenses, people can change the focus of the lens themselves. There are several ways to do this. The one I have developed involves spectacles that have chambers filled with silicon oil. If you fill the chamber with oil, the lens curves out; if you let the oil out of the chamber, the lens curves in. In this way, people can adapt the lens to their own vision needs.”
How do you get the glasses to the people who need them?
“It’s all a question of how to scale up, and how to make enough adspecs for one in every two people in the world. One pair of adspecs currently costs around $19, but that cost has to be brought way down. One way to distribute the glasses is through local NGOs. There is a program in Liberia at the moment through which about 1,000 people, many of them teachers and teacher trainees, have received adspecs. You just need someone to show them how to adjust the glasses.”
Is it difficult to adjust the glasses?
“The process is straightforward. You just need to show people what to do, monitor that they do it correctly, and that’s it. All that matters is that the instructions are correct and that the device is of good quality. There are about 30,000 adspecs in use in 15 countries, but I have a vision to get a billion people wearing the glasses by 2020. Lack of corrective eyewear is not just a health issue, it’s an educational, economic, and quality of life issue, too.”