Verily and Alcon have announced they are putting their work on a smart contact lens to monitor glucose levels through the tear film on hold, saying there was insufficient consistency in the correlation of measurements obtained using tear glucose and blood glucose concentrations to support the requirements of a medical device.

Announcing the move in a blog on Verily’s site, the company’s chief technical officer Brian Otis said this was in part associated with the challenges of obtaining reliable tear glucose readings in the complex on-eye environment.

Otis said the smart lens programme, begun four years ago, had evolved into a versatile electronics platform that could support actions, like sensing and transmitting data, on the eye. Together with Alcon, he said Verily had developed methods to integrate wireless electronics and miniaturised sensors into a contact lens and had so far directed the electronics platform at three different areas of care.

He said the companies’ joint work on a smart accommodating contact lens for presbyopia and a smart intraocular lens for improving sight following cataract surgery was continuing.