Cell Phone Software Will Diagnose Eyeglass Prescriptions

A new technique from MIT uses a cell phone and a small piece of plastic in its attempts to to replace bulky eye prescription equipment.

Nick Barber: Diagnosing Eyeglass prescriptions in developing countries typically requires this bulky case of trial lenses and a trained healthcare worker. But thanks to research from the MIT Media Lab, a new technique using a cell phone and a small piece of plastic hopes to achieve the same results. Ramesh Raskar: So imagine if you can use your mobile phone, hold it right next to your eye, click on a few buttons say calculate and you get your prescription for your glasses. The reason why we're able to do this today is the resolution of the mobile phones you have in your pocket is improving dramatically. Some of the most recent phones have a pixel pitch of about 30 micrometers and that allows us to create a wave front that's coming out of your display, by simply adding a small optical film, something you can just make for about $0.50 drop it on top, so that the wave front that's coming out of it can be manipulated to effectively compensate for vibrations in your eye. Nick Barber: The software that runs on a phone called Perfect Sight asks users to alien dots on a screen while looking through a plastic device like this. Once finished the program provides an eyeglass prescription. The researchers think that something like this that's software based will end up computing a prescription more accurately than the traditional method of trial lenses. Ramesh Raskar: What we say is that just deciding what your prescription should be based on when it looks most clear is not a very objective measure, what you should be using is a mechanism where can convert it below the estimate problem into an alignment problem. So in our prototype all we do is convert a software display pattern into a task where you have to align those patterns and its an easy, very easy task for anybody to see whether two lines have been aligned. And as I said earlier when the abruption of the eye has been compensated for the two lines will actually appear aligned to the user and the required number of steps to align those lines tells us what the prescription is. Nick Barber: The plastic pieces cost about one to two dollars each today, but the group thinks that mass production could drive them down to only a few cents each. The team at the MIT Media Lab have been working on the project for less than a year and will began field testing in Boston this summer and later in developing countries. They play into commercialize this system and initially target parts of Africa and Asia. Reporting from the MIT Media Lab in Cambridge I'm Nick Barber IDG news service.