Remember Bokodes, MIT’s tiny replacement for barcodes and the like? Their holographic nature enabled them to represent different information from different angles, and it’s this property that allows the tech behind them to be used in a very different and even more useful way: figuring out just how busted your vision is. The Camera Culture team at MIT’s Media Lab evolved that tech into a $2 box that refracts the image displayed on a smartphone screen. When combined with an app that displays a set of dots and lines, the user can manipulate the image until things look to be perfectly aligned. Once complete, the app spits out a prescription and you’re just a quick trip to your local mall-based eyeglasses joint away from perfect vision. The goal is to make it easier for optometrists in developing countries to quickly and easily find glasses for people, but an app that could save a trip to the doctor’s office is a wonderful thing regardless of where you are.