Those info-streaming retinal displays from the Terminator movies may be closer to fact than fantasy, according to researchers at the University of Washington and Aalto University, in Finland, who are developing a computerized contact lens that could be used to display data — like emails and text messages — right in front of your eyes.
Their latest study was just a proof of concept: so far, the contact lens controls only a single pixel. But the authors say it shows that lenses with multiple pixels, perhaps hundreds — enough to stream messages — are possible. The lenses could also be used to overlay information on the real world or be used for navigation or gaming. They could be synced with biosensors in the wearer’s body to display real-time updates of health data like blood-glucose levels.
How does it work? The scientists embedded a tiny LED with sapphire into the center of a plastic contact lens. They laid a circular antenna around the circumference of the lens and connected it with a circuit to the LED. Using remote radio frequency transmission, the scientists could control the pixel.
Problem is, the human eye has a minimum focal length of several centimeters, so it isn’t able to see clearly anything that close to its surface. To solve that problem, the scientists created a separate, thinner and flatter lens, called a Fresnel lens, that focuses light, and used it to project the image of the LED directly onto the retina, making it legible.
The researchers then tested their creation by fitting the lenses into the eyes of anesthetized rabbits. The animals seemed to tolerate the lenses well for short periods, and the researchers didn’t see any abrasions, thermal burning or other potential negative effects, which bodes well for potential future testing in humans.
The lenses are still crude prototypes, however, and need much refinement before being introduced to humans. As Discovery News reported:
The computerized lens is made from polyethylene terephthalate (PET), a hard plastic that doesn’t allow airflow to the eye, limiting usage to only a few minutes. Although the device could be powered from about three feet away when outside the eye, that distance narrowed to about an inch when the contact was in an actual eye. While a single pixel lighting up could potentially be useful as a warning, without the focusing micro-lenses, the rabbits only saw a blurry shadow.
Next, the researchers are hoping to improve the design of the antenna, incorporate the flat-lens technology into the computerized lens, make them more comfortable for the wearer, and increase the number of controllable pixels in the lenses.
“If we can make them as comfortable as normal contact lenses, you don’t feel you’re wearing them,” co-author Babak Amir Parviz, an associate professor of electrical engineering at the University of Washington, told Discovery. “In a sense, it’s the ultimate electronic gear that is totally unnoticeable.”
The research was published in the Journal of Micromechanics and Microengineering.