A team of engineers at the University of Washington, Seattle, have designed a low-power sensor that could be placed permanently in a person’s eye to track changes in eye pressure. The sensor would be placed during cataract surgery and would detect pressure changes instantaneously, then transmit the data wirelessly using radio frequency waves, they say.

The device would be embedded into an artificial lens with its antenna circling the perimeter, and the sensor and radio frequency chip inside. Since it would be placed into the eye during cataract surgery, it would not require a second surgery.

Currently, there are two ways to check eye pressure, but both require a visit to the ophthalmologist. Since those most at-risk for glaucoma may only get that pressure checked a few times a year, a “smart” and more functional replacement lens that continually monitors pressure and detects changes would be a big advantage for the three to four 4 million people each year who have surgery to remove blurry vision or glare caused by a hazy lens.

The UW engineering team, which includes Brian Otis, an associate professor of electrical engineering who’s also with Google Inc., built a prototype that uses radio frequency for wireless power and data transfer. A thin, circular antenna spans the perimeter of the device, roughly tracing a person’s iris, and harnesses enough energy from the surrounding field to power a small pressure sensor chip. The chip communicates with a close-by receiver about any shifts in frequency, signifying a change in pressure. Actual pressure is then calculated and those changes are tracked and recorded in real-time.