A new entry in the Science Advances journal for January 2018 suggests that scientists may be getting closer to measuring blood glucose levels in diabetics without the use of needles. The latest attempt comes from a group of researchers from various schools at the Ulsan National Institute of Science and Technology, as well as from the Sungkyunkwan University led by Jihun Park of UNIST. As is outlined in the resulting research paper, which is titled 'Soft, smart contact lenses with integrations of wireless circuits, glucose sensors, and displays,' the researchers were able to create a contact lens which could respond to changes in glucose and provide results via an LED panel on the lens itself.
The lenses are a combination of flexible electronics and an LED embedded into the same material used in regular contact lenses. By design, the circuitry and sensors leading to the LED cause the light to turn off if a set threshold of glucose is reached. That would provide the wearer with an easy-to-notice means to tell when their blood sugar is too high. Unfortunately, there's no evidence yet to prove that blood glucose can or does correspond to the measurement of glucose, or other chemical compounds or substances found in fluids these lenses can measure unintrusively, such as tears. Moreover, the scientists involved in the project utilized an artificial tear solution with heightened levels of glucose in order to stimulate a response both in the initial materials test and in the subsequent rabbit-based tests. No human testing has been conducted and the design is still very much in a highly experimental phase, as this initial test appears to be a proof of concept and shows that the design does not harm the body or overheat.
Beyond that, the tests suggested that being worn on the eye directly did not interfere with the lens's ability to read or respond to increased glucose levels. So although it may be too early to deem the study a resounding success, there are still useful details to be gained from the research. In fact, the discovery could lead to other advances in health measurement methodology through wearables, even if it turns out it can't be used to detect a spike in blood sugar - if a corresponding reaction to such a spike can't be found in the tear ducts.