Detecting diabetes is not difficult, just measure the amount of glucose in the blood. Several tests have already been doing that and it shows that it is possible to measure those variables using contact lenses (Google itself is working with this subject). Even so, the possibilities of measuring health problems using this technique are much broader, and in IEEE they indicate that there is already how to help detect glaucoma being made, thanks to measures of the pressure of the eye.
Researchers at the Ulsan National Institute of Science and Technology in South Korea are using a hybrid film made of graphene and silver nanowires to create contact lenses with conductive, transparent and flexible electrodes. They are able to detect multiple biomarkers, including indicators of intraocular pressure, diabetes mellitus, and other health conditions.
To detect intraocular pressure, a dielectric layer is sandwiched between two hybrid films, so that they become a capacitor that responds to intraocular pressure. It is possible to verify if someone has high blood pressure, although it is important to note that not all people with high intraocular pressure have glaucoma, and not all glaucoma patients have high blood pressure in the eye.
To detect diabetes, the top layer of the hybrid film is exposed to tears and it detects glucose. In a selected region of the film, researchers removed the nanowires, leaving only graphene coated with an enzyme that selectively binds to glucose, thereby changing the resistance of graphene.
Resistance, inductance and capacitance changes in these two detection modes can be monitored wirelessly in real time.
The use of two-dimensional graphene (2D), with its properties of being highly transparent, conductive and flexible, is fundamental to create this type of devices. However, it may take a while before we see them in the market.