Soft, Smart Contact Lenses Can Monitor Glucose Levels In Your Tears

The team hope their lenses will mean diabetics will no longer have to prick themselves to test glucose levels. Park et al. 2018

Humans may be one step closer to becoming cyborgs. Researchers have developed a soft, flexible contact lens that monitors glucose levels in tears and tells the wearer if they are hyperglycemic. The team hope the device will one day be used by those with diabetes so that they will no longer have to prick themselves to monitor their blood sugar levels.

The contacts have a tiny glucose sensor and LED light incorporated into them. An antenna then picks up radiofrequency signals from a transmitter and converts that to electricity, which is fed to a light that shines green. When the sensor registers that the glucose level in one's tears has topped a set limit, it cuts the power to the LED and the light goes off. The LEDs are specifically positioned to face outward so that the wearer cannot normally see them.


This means that by looking in a mirror, anyone wearing the lenses can see when they need to adjust their insulin levels. The astute among us will have realized that it seems a little odd to have the lenses only turn off when glucose levels rise, and this has not passed by the researchers unnoticed, who said they might see if they can reverse that bit in the future.

After testing the contact lenses on rabbits, and publishing their results in Science Advances, the team found no signs that the lenses were uncomfortable.

The researchers constructed the contact lenses by using flexible, transparent components whenever possible. Only a few bits of the lens are not flexible, including the glucose sensor, which is made from a rigid silicon pad. However, the team separated the pad into two pieces and connected them with flexible wires to help with that.

Overall, all components in the lens are 1/100 the thickness of the soft contact lens in which they are placed. Not only that, but all bits of the tech that could not be transparent are located in sections that are over the iris where they cannot be seen by the wearer. This means that – in theory at least – the user should not be able to see any of the electronics.


The lenses are yet to be tested on humans, but the team are fairly confident that they will be successful. Don’t go rushing to your pharmacy just yet though, as they reckon it may take another five years to perfect them in people.


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