$20 Self Adjustable Pump-Action Glasses

The lenses comprise flexible membranes containing silicone oil. Using syringes (seen in the picture), the amount of oil can be adjusted and the refractive index of the lenses changed. The syringes are detachable.

This is big, because it means a single, uniform product can be mass produced and then tweaked at its destination without specialized equipment.

The goal is to distribute these in countries where ground glass (or plastic) lenses are too expensive and doctors are in short supply.

From The Telegraph,

His aim is to eventually reach 100 million people a year, with a target of one billion in total by 2020

Also see the writeup in the Washington Post