Specialist Contact Lenses: Smart lenses target glucose monitoring

Creating an electricity-conducting material on a contact lens is the first step towards a smart lens that darkens in warning as its diabetic wearer’s glucose levels drops, a researcher says.

University of South Australia associate professor, Dr Drew Evans, was part of the team able to break new ground by synthesising a conductive polymer directly onto the flexible materials used to make contact lenses.

Another theoretical possibility of such technology was a lens capable of working like a computer screen, displaying information – yet only to the wearer.

Previously, conductive polymers had been added to hard surfaces like glass, but not onto the soft, changeable materials that made up lenses, Dr Evans added: “This makes depositing coatings on them a challenge.”

The team, with its partner Contamac, was currently working on making the lenses sense and respond to changes in the chemistry of the wearer’s tears, he said. “This requires no power,” he highlighted.“The idea is that the lens would darken when the glucose level drops, immediately telling the wearer to ingest some sugar. Once the glucose level is restored the lens would become transparent again, telling the wearer they were OK again,” he explained.

However, Dr Evans warned that the combined polymer material had not yet been tested in a lens on an eye, explaining: “This [technology] is a long way off at the moment.”His team is now focusing on the robustness and safety of the material, he said.“Customers need to know the lens is durable enough to withstand the rigors of being worn on someone’s eye,” he noted.

Conductive polymers on a glass surface could already produce pixels and should be capable of doing the same to display text or images from a lens, Dr Evans said. “Translating this to a contact lens shouldn’t be impossible. When considering these pixels, there is a need to power them and to tell each pixel to behave in a certain way. This requires just as much research as our current project,” he concluded.