Bumped into this early today and thought I'd pass it along in case anyone is dealing with diabetes. It sounds really cool. If they ever perfect this, I imagine it would have a profound impact on those that deal with diabetes.
http://www.gizmag.com/color-changing-contact-lenses-diabetic-glucose/13682/
http://www.gizmag.com/color-changing-contact-lenses-diabetic-glucose/13682/