The average auto refractor--that clunky-looking device eye doctors use to pinpoint your prescription--weighs about 40 pounds, costs $10,000, and is virtually impossible to find in a rural village in the developing world. As a result, some half a billion people are living with vision problems, which make it tough to read and work.
Ramesh Raskar knew fixing this problem would be tricky. It required a new way of thinking about eye tests--and a new kind of device, one powerful enough to support high-resolution visuals, cheap enough to scale, and simple enough to be used by just about anyone. The MIT professor briefly toyed with stand-alone options, which were complicated and costly. Then he reached into his pocket and pulled out an unexpected savior: his iPhone.