Scientists have designed a smart contact lens to measure the wearer’s blood sugar level without necessarily using a needle. The new lens will also be able to monitor body temperature and cholesterol.
The lens is made out of the same transparent, flexible material that is in some soft contacts on the market.
Inside, the researchers embedded electronics including a little LED light and a glucose sensor.
If glucose levels climb above a certain level, the continuously lit LED light flickers off to alert the wearer, the researchers report today in the journal Science Advances.
The scientists, led by Jang-Ung Park at the Ulsan National Institute of Science and Technology in the Republic of Korea, tested the contact lens using artificial tears spiked with sugar to mimic the low glucose levels measured in tears by earlier studies.
They also gave it a trial run in rabbits: the LED stayed on until the researchers squirted a glucose solution into the rabbit’s eye and then the LED turned off, just like it’s supposed to. So far, it hasn’t been tested in humans or with human tears, however.
The device is the latest attempt to develop a needle-less blood sugar monitor for diabetics.
"Building the circuitry on a flexible contact lens is impressive," says John L. Smith, former chief scientific officer of Johnson & Johnson’s glucose monitoring division and author of The Pursuit of Noninvasive Glucose: Hunting the Deceitful Turkey.
Though the glucose readings from tears just do not reflect the levels in blood reliably enough to guide treatment decisions for people with diabetes.
“It’s an unreliable measure of blood glucose and that’s something you have to measure with great reliability or you will expose people to harm,” Smith says.
