Japanese Biomedical Researchers Develop World’s First Self-Moisturizing Smart Contact Lenses
Source: Thailand Medical News Jan 27, 2020 4 years, 9 months, 6 days, 13 hours, 53 minutes ago
Biomedical researchers at Tohoku University in Japan have developed a new type of
smart contact lenses that can prevent
dry eyes. The
self-moisturizing system, which is described in the journal
Advanced Materials Technologies, maintains a layer of fluid between the contact lens and the
eye using a novel mechanism.
Typically,
smart contact lenses are wearable devices that could accelerate vision beyond natural human capabilities. They are being developed for a wide range of applications from non-invasive monitoring to vision correction to augmented reality display.
Lead researcher, Professor Dr Matsuhiko Nishizawa, a biomedical engineer at Tohoku University told
Thailand Medical News via a phone interview, “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.”
Among the common significant problems with
contact lenses is they can cause “
dry eye syndrome” due to reduced blinking and increased moisture evaporation.
Dry eye syndrome can lead to corneal wounds and inflammation as well as a feeling of discomfort.
So as to tackle this important problem, the
biomedical researchers developed a new mechanism that keeps the lens moist. The system uses electroosmotic flow (EOF), which causes liquid to flow when a voltage is applied across a charged surface. In this case, a current applied to a hydrogel causes fluid to flow upwards from the patient’s temporary tear reservoir behind the lower eyelid to the surface of the
eye.
Image of a self-moisturizing soft contact lens that supplies tears via electroosmotic flow
from the temporary tear reservoir behind the lower eyelid. Credit: Tohoku University
Dr Nishizawa added, “This is the first major demonstration that EOF in a soft
contact lens can keep the lens moist”
The
biomedical researchers also explored the possibility of using a wireless power supply for the
contact lenses. They tested two t
ypes of battery, a magnesium-oxygen battery and an enzymatic fructose-oxygen fuel cell, both of which are known to be safe and non-toxic for living cells. They showed that the system can be successfully powered by these biobatteries, which can be mounted directly on the charged
contact lens.
Additional research is needed to develop improved
self-moisturizing contact lenses that are tougher and capable of operating at smaller currents.
Dr Nishizawa further added, “In the very near future, there is scope to expand this technology for other applications, such as drug delivery.”
Reference: “Self‐Moisturizing Smart Contact Lens Employing Electroosmosis” by Shinya Kusama, Kaito Sato, Shotaro Yoshida and Matsuhiko Nishizawa, 28 November 2019, Advanced Materials Technologies. DOI: 10.1002/admt.201900889
