Glasses for poor countries

Like the "one laptop for a child" campaign, this is a fantastic, disrupting, useful innovation.

Professor Joshua D Silver, while studying mirrors, discovered a new way to change the curvature of lenses. He applied this to create a new form of liquid-filled corrective lens, that could be easily adjusted by the wearer to correct the vision of over 90% of people requiring correction. This is particularly useful for people in developing countries where specially trained optometrists are not available.
This kind of glasses cost as much as 20 US$, but when in production their cost could go down up to 1$.
Check out the video on YouTube.