How Contact Lens Displays Work

The Rabbit With Bionic Eyes

It can only power a single pixel, but that's just the beginning.
It can only power a single pixel, but that's just the beginning.

To be perfectly clear, the first rabbit to wear these high-tech lenses was somewhat dead at the time of the experiment. After all, what kind of maniac slips untested bionic contacts on a live rabbit? Not Babak Parviz, that's for sure.

Parviz is a bionanotechnology researcher at the University of Washington in Seattle. He's also the guy who led a team of U.S. and Finnish scientists in the development of these amazing prototypes.

Normal contact lenses are polymer discs crafted into just the right shape to sit comfortably on your eyeballs and correct vision. Parviz's lenses are quite similar, only they feature a few added components:

  • A single-pixel light-emitting diode (LED) made from blue sapphire, positioned in the dead center of the lens
  • A circular antenna placed around the inside lip of the lens to receive wireless energy and radio transmissions
  • An integrated circuit (IC) that controls energy flowing into the LED and allows researchers to control its function

Parviz and his team encapsulated all of these parts inside a protective, biocompatible polymer. After three successful tests on rabbit cadavers, they slipped the lens on the eye of a live, sedated rabbit. They then used a remote radio frequency transmitter to activate the lens and watched the LED glow blue. If the rabbit were conscious, it would perceive this as a glowing, blue blur.

Follow-up examinations revealed no damage to the rabbit's eye, though the hard plastic contact would likely feel uncomfortable -- and would be usable only for a short time since it doesn't allow the eye to breathe. Also, while the researchers were able to power the lens from about 3 feet (0.9 meters) away outside the rabbit's eye, the distance narrowed to a mere inch when the contact was in place.

But that's how things begin: crude, somewhat painful but in proof of a larger concept. Just remember that back in the 19th century, some of the world's first contact lenses were actually made of glass.

Another remarkable contact lens prototype emerged in 2010, thanks to professor Jin Zhang at the University of Western Ontario. Zhang's experimental lenses change color with the user's glucose levels. See, the live cells on the surface of your eye contain many of the crucial biomarkers that doctors look to in the bloodstream.

In partnership with Microsoft Research, Parviz and his team also are working with contact lens display technology to create a single, biomonitoring contact lens.

Switzerland's Sensimed even has a single-use lens on the market called the Triggerfish that measures eye pressure over a 24-hour period to detect glaucoma. The Triggerfish transmits this data to a circular antenna taped around the patient's eye, which in turn connects to a battery-powered recorder.

These projects point toward a most remarkable future, one where high-tech lenses not only relay information from the computerized world, but also keep constant tabs on the conditions inside our bodies.