November 22, 2011
The Contact Lens Of The Future
Contact lenses have been around for decades, correcting vision problems and giving cosmetic or therapeutic aid, but what about using them as a mini-monitor to project text messages or short emails right in front of your eye? Sound like science fiction?
Well, according to US researchers at Washington University, the idea of wearing computerized contact lenses is very close to reality. The futuristic technology has taken a step closer with the development of a prototype lens that could potentially provide the wearer with hands-free information, messages and updates.Theoretically, such a device could enable a wearer to read emails and text messages, view images and perhaps even watch videos using a computer display just millimeters from the retina.
The computerized contact lens was demonstrated by testing it on live eyes, showing no signs of adverse reactions or side effects.
Currently the contact lens contains only a single pixel -- not even close to the hundreds or thousands of pixels needed to properly display, texts, images and film. But the researchers see this as a “proof-of-concept” for producing lenses with multiple pixels which could allow the wearer to one day read short emails and text messages. Hwever, there are many issues that still need to be resolved before such a device can be sustainably marketed, such as finding a good power source.
The Washington University researchers worked with a team from Aalto University in Finland to create the device. It consists of an antenna that harvests power sent out by an external source, as well as an integrated circuit to store the energy and transfer it to a transparent sapphire chip containing a single blue LED.
Currently, the prototype can only work if it is within centimeters of the wireless battery. And the micro-circuitry is only enough for one light-emitting diode, according to a report by the Journal of Micromechanics and Microengineering.
Despite those issues, initial safety tests in rabbits have gone rather well, showing no signs of obvious adverse effects. The positive results give them reason to continue their work, envisaging hundreds more pixels being embedded into the lens to produce complex holographic images.
Another major problem the researchers had to overcome was the fact that the human eye only has a minimum focal distance of a few centimeters and cannot resolve objects on a contact lens. Any information projected onto the lens would most likely appear blurry.
To overcome this obstacle, the team incorporated a set of Fresnel lenses into the device that focus the projected image on to the retina. Fresnel lenses are much thinner and flatter than the conventional bulky lenses.
“Our next goal is to incorporate some predetermined text in the contact lens,” Professor Babak Praviz, one of the study´s lead researchers, told BBC News and tHuffington Post.
Because manufacturing electrical circuits involves using inorganic materials and toxic chemicals, there are concerns for the health of the human eye. Researchers built the circuits from layers of metal only a few nanometers thick, less than one thousandth the width of a human hair, and constructed the LEDs measuring one third of a millimeter across.
Dr Praviz and his colleagues are not the only scientists working with this type of technology.
A Swiss company called Sensimed has already released a smart contact lens that uses built-in computer technology to monitor the eyes of glaucoma patients, reports Michelle Roberts of BBC News.
The technology is also going into glasses, goggles and other headsets designed to help users do everything from skiing to watching 3D movies.
Other areas the technology could find its way into are GPS systems, teleprompts, and video gaming. There are also military and medical implications, including allowing diabetes patients to monitor their blood sugar levels.
On the Net:
- Washington University in St Louis
- Aalto University
- Journal of Micromechanics and Microengineering