Wireless contact lenses being developed

Wireless contact lenses that transmitted critical information to key characters in science-fiction movies may be moving a step closer to reality after researchers constructed a prototype computerized contact lens.   Researchers from Aalto University, Finland and the University of Washington said the prototype could provide hands-free information updates to the wearer.   "There were no signs of adverse side effects," EE Times India quoted the researchers as saying.   Initially, the contact lens device contains only a single pixel but the researchers see this as a "proof-of-concept" to make lenses with multiple pixels.   Such lenses could eventually be used to display short emails and text messages literally before your eyes.   According to the researchers, the device could overlay computer-generated visual information and have applications ranging from gaming to navigation.   It could also be linked to biosensors in the user's body to provide up-to-date information on glucose or lactate levels.   Problem   The contact lens has an antenna to harvest power sent out by an external source, and an integrated circuit to store this energy and transfer it to a transparent sapphire chip containing a single blue LED.   But one major problem the researchers had to overcome was the fact that the human eye, with its minimum focal distance of several centimeters, cannot resolve objects on a contact lens.   Any information projected on to the lens would probably appear blurry, they noted.   To address this, the researchers incorporated a set of Fresnel lenses into the device.   Fresnel lenses are much thinner and flatter than conventional lenses, and were used to focus the projected image on to the retina.   The researchers first tested the lens to the eye of a rabbit, under the strict guidelines for animal use in the laboratory, to evaluate the effect of wearing the contact lens on the cornea and the body in general.   A fluorescent dye was added to the eye of the rabbit to test for any abrasion or thermal burning.   "We need to improve the antenna design and the associated matching network and optimise the transmission frequency to achieve an overall improvement in the range of wireless power transmission," said Professor Babak Praviz of the department of electrical engineering, University of Washington in Seattle.   "Our next goal, however, is to incorporate some predetermined text in the contact lens," Praviz added. — TJD, GMA News