People with diabetes have trouble regulating the amount of glucose (known as blood sugar) in their blood. When the blood sugar content of a normal person is high, insulin will work overtime to convert the blood sugar into other things and store it, so that the blood sugar will drop. However, diabetic patients lose the ability to synthesize insulin, and their blood sugar will remain high. Long-term high blood sugar levels can damage organs and cause various chronic diseases, so regular monitoring is required.
Of course, patients can monitor blood glucose with a blood glucose meter, but it is painful and inconvenient to constantly prick their fingers to take blood. At present, there are several methods of blood sugar monitoring. For example, there is a sensor worn on the arm that continuously measures blood sugar via a small wire implanted in the skin. People can download this data to a phone or computer to see how their blood sugar levels change over time. In addition, others are working on patches that detect sugar in sweat.
South Korean researchers recently developed a contact lens that can continuously monitor sugar in tears. Previous studies have shown that the sugar in tears is closely related to blood sugar.
The contact lens consists of a glucose sensor and LEDs. The sensor sends an electrical signal to the LED, which remains lit. When the sugar level exceeds the standard, the sensor no longer sends an electrical signal and the LED turns off. By looking in the mirror, the wearer can check whether the light is on or off, and know whether his blood sugar exceeds the standard, so as to make corresponding adjustments to medication or lifestyle. For those potential patients with diabetes, it also helps to give early warning.
Both the glucose sensor and the LED are located on the side of the pupil, are small enough to not interfere with vision, and are non-irritating.
To test the contact lens, the researchers attached it to a rabbit’s eye. When they sprayed glucose-laced tears into its eyes, the LEDs went off.
It does have the one downside, though, that it doesn’t give an accurate reading, it can only tell you when your blood sugar is over the limit, which means you can’t see trends in your blood sugar over time.