Smart Contact Lenses to Monitor the Glucose in Tears

Early attempts at 'smart' contact lenses used rigid and opaque embedded electronics. Researchers  led by Jihun Park, a materials scientist at the Ulsan National Institute of Science and Technology in South Korea, have designed a set of components out of soft and flexible electronic materials that - when possible - are also transparent. They included two devices, an antenna and a rectifier, that capture radio frequency signals from a nearby transmitter and convert them to a small amount of electricity. That charge powers a glucose sensor and a tiny green LED, which shines outward so it is visible in a mirror but doesn't interfere with the wearer's vision. If the glucose sensor registers elevated levels, the LED turns off, warning a diabetic wearer that they may need to adjust insulin levels.