New research suggests that in the future contact lenses might be able to help diabetics monitor their blood sugar levels. They would work by changing their appearance in line with the wearers changing blood sugar levels.
Currently, diabetics have to draw and test blood to track the changes in their blood sugar levels. This is painful and inconvenient. Monitoring blood sugar levels via the changing appearance of contact lenses would be a much less painful alternative. It is also a logical next step as diabetes often affects sufferers’ vision meaning that they have to wear glasses or contact lenses.
These contact lenses work by sensing changing levels of glucose in the wearers’ blood. They contain boronic acid which react to glucose in the wearers’ tear ducts producing fluorescence. By shining a blue light into their eye, the wearer can gauge the intensity of the glow which indicates their blood sugar levels.
Another option being tested, and which would work in a similar way, is a colour changing contact lens. This would change from green to yellow to orange to red. As a result the wearer would be able to get a more accurate reading of their blood sugar level.
Although the level of glucose in tears takes around half an hour to match the body’s sugar levels, the researchers did not think that this would pose a problem. This is because the majority of diabetics have hour long gaps (or more) in between their blood tests. Therefore, the contact lens approach would be more timely.
Although there are already other glucose monitoring system that do not rely on skin pricking, this method offers a significant advantage over current models.
The existing model is worn as a bracelet and applies a small electrical current to the skin. This draws the fluid that sits between the cells through the skin so that it can be tested for glucose. The disadvantage of this method compared to the glucose testing contact lenses is that its manufacturers still recommend that users carry out occasional blood tests.