the Awesome Highlighter

He's now going to add some extremely small light emitting diodes   remove

"The display size is one of the main reasons that laptops, cellphones, PDAs, etc are not smaller today. If we move the display to a contact lens, we can significantly remove the physical constraints on mobile devices."   remove

A microfabrication technique known as self-assembly relies on capillary effects to bring together pre-shaped pieces of circuit.   remove

The prototype contact lens - which will eventually contain LEDs - has yet to be powered up. That key step, says Parviz, is several months off. "We're looking at two different ways to transmit power. One is radio frequency power transmission. We need antennae on these contact lenses anyway because we need to transmit data to them. The other way we're looking at right now is to incorporate photovoltaic [solar] cells."   remove

Power isn't the hardest problem. A contact lens sits directly on the surface of the eye, much too close for the eye's lens to focus on. "To create the focused image we have to manipulate the light rays," says Parviz. "You can create a focused image if you use laser instead of LEDs."   remove

If shining very low power diode lasers on to the retina seems risky, then microLEDs might be the answer. These provide diffuse light and, to make them work, Parviz might integrate an array of individual micro-lenses into the contact lens. "If the pixel [the microLED] is close enough to the micro-lens, it will generate a virtual image that could be 30cm or more away from the surface. Our eyes can focus on this now."   remove

Parviz talks about augmented reality, such as superimposing text messages or direction arrows on your view of the world.   remove

But even trivial applications will require a high-resolution display.   remove

"The focusing would be the real issue. These are incredibly close to the eye," says Wolffsohn of Parviz's plan. He adds that while dust in a contact lens is uncomfortable, you don't see it because it's just too close   remove

Nevertheless, Wolffsohn is attracted to the idea of putting electronics on to glasses (as has been done with some products already). There's more space and no biocompatibility issues, while image projection is an easier proposition. His verdict on using contact lenses as a display device?   remove

"They wouldn't be my starting point if I had this technology," says Wolffsohn. But whichever way this research goes, it's worth keeping an eye on.   remove