I've been fortunate enough that my eyes allow me to see my world clearly without the need for corrective vision (although I do wear computer glasses so working on my laptop all day isn't so straining on my peepers). For those of you who do need glasses, though, getting new ones and dealing with your changing visual acuity can be a pain. Soon, we may live in a time when you don't need a new pair of glasses every couple years, since engineers at the University of Utah created a pair of smart glasses that can adjust your prescription on the fly using water (via Neatorama).
The glasses, which you can see above are just a bulky (but promising) prototype at this stage, pairs with a smartphone app to adjust its prescription to meet all vision needs. They can also switch between two different prescriptions, which would be useful for somebody whose reading glasses are a different prescription than their everyday glasses, for example.
The lenses are made of a layer of glycerine between two flexible membranes, and the prescription is adjusted by electronics that push the rear membrane to change the curvature of the lens. This alters the focal length of the lens, which determines what your prescription is. A simple way to think about it is if your current glasses were more malleable, but could maintain their shape well enough to provide consistent vision correction.
Hopefully these glasses make it out of the testing phases, because this technology is super intriguing. Just, you know, not quite as thick-rimmed. In the meantime, read more about the research here.