Researchers at Tohoku University have developed smart contact lenses that has a self-moisturising system, as described in the journal Advanced Materials Technologies.
A major issue with wearing contact lenses is that they can cause “dry eye syndrome” due to reduced blinking and increased moisture evaporation. This condition can lead to corneal wounds and inflammation that can cause discomfort and lead to eye disease.
“Although there have been many recent advancements in new functions for smart contact lenses, there has been little progress in solving the drawbacks associated with wearing contact lenses day to day,” says Professor Matsuhiko Nishizawa, an engineer at Tohoku University.
Smart contact lenses have come a long way as wearable devices that is able to be developed for a wide range of application from non-invasive monitoring to vision correction to augmented reality display.
In a research by a team from Tohoku University, they have developed a new mechanism that maintains the moisture of the lenses by retaining a layer of fluid between the contact lens and the eye using a novel mechanism.
The mechanism uses electroosmotic flow (EOF), which causes liquid to flow when a voltage is applied across a charged surface. In this context, a current applied to a hydrogel causes fluid to flow upwards form the patient’s temporary tear reservoir behind the lower eyelid to the surface of the eye.
Professor Nishizawa shares that this is the first time that EOF is shown to maintain moisture in a soft contact lens.
Exploring the possibility of using a wireless power supply for the contact lenses, the researcher testes two types of batteries, a magnesium-oxygen battery and an enzymatic fructose-oxygen fuel cell. Both types are known to be safe and non-toxic for living cells. They were then able to demonstrate that the system can be successfully powered by these biobatteries, which can be mounted directly on the charged contact lens.
Further, the team will continue to improve the technology for more robust contact lenses that is capable to operate at smaller currents. The team is also looking to expand the technology for other applications such as drug delivery. [APBN]