It’s a computer small enough that it can be implanted inside a human eye, and it includes a tiny radio so it can communicate with the outside world.

Researchers in at the University of Michigan created the minuscule computer — less than a cubic millimetre large — to sit inside the eyes of glaucoma patients and monitor the pressure of fluids in the eyeball. Once a week, the patient would return to the doctor who would download the information over a radio link. But with the tiny size of the monitoring computer, and super low power consumption that can run off the energy of ambient light, researchers are now imagining a future in which dozens, or even hundreds, of the tiny devices are implanted in human bodies to monitor everything from health to location to mood.

“The applications for systems of this size are endless,” said Dennis Sylvester in a release from the university. “This is the first true millimetre-scale complete computing system.”

Potential long-term uses could be tiny networks of surveillance devices, medical monitoring devices – such as the eye pressure monitor in this case – and environmental monitoring.

The next step for researchers is to further reduce the computer’s power consumption so that it can be paired with batteries on the same scale.