Chris Geddes, from the Center for Fluorescence Spectroscopy at the University of Maryland, is working on contact lenses that change their appearance according to the wearer’s blood-sugar level, allowing people with diabetes to monitor their levels.

The system makes sense because many people with diabetes also need glasses or contact lenses due to the way diabetes affects the blood vessels in the retina.

To make glucose-sensing contacts, boronic acid was added to disposable contact lenses. Moisture from the tear ducts contains glucose that binds with the molecules of boronic acid, with the reaction causing fluorescence. A handheld device flashes a blue light into the eye and measures the intensity of the resulting glow, letting the user know their blood glucose level.

The team is looking at other options. Sensor spots could be placed around the contact lens to monitor glucose, as well as sodium, cholesterol and potassium.

Another project is a contact lens that would change colour like a traffic light – from green to yellow to orange to red – enabling the wearer or an observer to determine a broader range of blood sugar level, from too low to too high.

Via New Scientist.

Other researches on “medical” contact lenses: contact lenses that release controlled doses of drugs to treat eye diseases, contact lenses containing embedded particles that slowly release drugs directly where they’re needed.