When wearing contact lenses, the expectation is to experience a better view of the outside world, focusing on faces, screens and more. But what if you could also monitor the internal world, that is, the vital parameters of the body?
Until yesterday, contact lenses with built-in sensors for measuring the intraocular pressure (IOP, important sign for detecting glaucoma) were too stiff, bulky and could even partially block vision. Totally unsuitable. And today?
A turning point that changes the vision
A groundbreaking project has just been successfully tested on a group of volunteer volunteers: soft, clear contact lenses capable of quantitative IOP measurements in real time, using a smartphone, according to a new study published in the magazine Biomedical Engineering.
More importantly, the new device successfully performed all functions wirelessly without inducing inflammation for the 10 human participants, and this could have serious benefits for people suffering from glaucoma.
Smart contact lenses that detect a key symptom of glaucoma
The new contact lens uses a wireless antenna, a strain sensor, capacitors and other elements that allow for remote communication. Tested on rabbits it showed a very low amount of magnetic fields, comparable to that of a commercial tonometer (the "traditional" diagnostic tool to monitor glaucoma). On the 10 human volunteers, then, it proved perfectly safe with zero inflammation observed.
Le smart lens they can measure heart rate, body temperature, electrical activity of the heart, glucose - lactate and alcohol concentration in sweat, tears and saliva. Measuring all of these factors is crucial in diagnosing many diseases.
The ideal observation point
Medically, the eyes are a great choice for measuring these vital signs. Electrical sensors are continuously exposed to tear fluid samples, for example. As mentioned, this feature of smart lenses allows the analysis of many pathologies, but the study, for now, has focused on the detection of glaucoma.
Glaucoma it is an optic neuropathy that often leads to irreversible vision loss, and IOP is the only risk factor that scientists are sure they can control. The only means we have to cure glaucoma is by lowering the intraocular pressure.
Typically, IOP measurement is done with various forms of tonometry, but they lack the clinical specificity required for fully effective monitoring. This smart contact lens is currently the most promising candidate for wearable sensing technology. It maintains physical contact with the cornea and detects corneal limbus expansion, a key symptom of intraocular pressure.
A triumph, and already new challenges on the horizon
In other words, the new smart contact lens can monitor a key signifier of glaucoma with minimally invasive technology, comparable to regular contact lenses. But there are still challenges to be faced for the new design before implementing it on a large scale. You need to amplify the biosensor signal, for example, so that the lens data is not submerged by background electromagnetic noise. And, if we wanted to leave the clinical field and enter the mass market, we would need to miniaturize all the tools necessary to “read” the data of these lenses.
