Media playback is unsupported on your device

'Smart contact lens' could help millions with diabetes

17 January 2014 Last updated at 10:57 GMT

Google has announced it's testing a smart contact lens that can help measure glucose levels in tears.

The contacts contain a tiny wireless chip and a sensor.

The company is hoping the technology could lead to a new way of helping people with diabetes manage their disease.

David Grossman reports for BBC Newsnight from Google headquarters in California.