Terminator Vision? Telescopic Contact Lenses in the Works
A telescopic contact lens mounted on a model eye, developed by researchers at the University of California San Diego with Paragon and Innovega.
CREDIT: UCSD, Paragon, Innovega
Imagine if you could wink your right eye and suddenly have your vision zoom in like a telescope? And then wink your left eye to return to normal vision?
That's one of the possible uses for telescopic contact lenses, a new technology developed at the University of California San Diego (UCSD) and the École Polytechnique Fédérale de Lausanne in Switzerland.
Taking this technology from a bulky, unwearable prototype to something you buy at LensCrafters, however, will require new or emerging technologies, possibly including 3D printing.
"The next question is, 'Can we do this in a way that won't cause people to claw out their eyes screaming?'" said Joseph Ford, the lead developer and a professor of electrical and computer engineering at UCSD. [See also: Bionic Eye Turns Off the Dark]
Optimizing the Optics
The scientists said this month that they've got the telescopic mechanism working. This specialized lens consists of two parts: a central circle that doesn't alter users' vision in any way; and surrounding that a ring of reflective, multifaceted metal that is folded in on itself to create the same effect as a standard, two-lens telescope.
To switch between a normal and a zoomed-in view, users need to wear a pair of eyeglasses similar to those that come with some 3D TVs. Wearing both glasses and contact lenses may seem counterintuitive, but these eyeglasses are necessary to control whether exterior light hits either the center, unaltered portion of the lens or the outer, telescopic part.
Tiny LCD panels in these eyeglasses act as a sort of shutter by polarizing the light that goes through it, directing it to either the center or outer portion of the lenses. The contact lenses are also polarized, so that any light that goes through the polarizing part of the glasses will then be unpolarized when it goes through the lenses, thus returning the light to normal visibility.
So the UCSD scientists have the "telescopic" part of the telescopic contact lenses working. Now they've shared that design with a number of partners, including Innovega Inc., a company that specializes in wearable computer interfaces, and Paragon Vision Sciences in order to find ways to make it comfortable to wear on a human eye.
For example, in the UCSD labs the scientists made the lenses out of a material called polymethyl methacrylate (PMMA), which was chosen in part because it is sturdy enough to hold detailing around the lenses' edges. But PMMA is impermeable to gasses — it can't "breathe"— so humans can't wear the lenses for more than a few hours.
Currently, Paragon Vision Sciences is developing a prototype lens made from rigid gas permeable polymers, a material already used in commercial contact lenses.
But the telescopic lenses have to be both thicker and larger than a normal contact lens, covering the entire front of the eyeball instead of just the cornea, like normal contact lenses do.
This actually makes the lenses easier to wear, Ford explained: the lenses are so thick that if they only covered the cornea then the act of blinking would bump them out of place, but since the telescopic lenses cover the entire front of the eyeball, they're already beneath the eyelid and won't obstruct a blink.
[See also: Eye Movements Could Be Next PC Password]
3D printing, significant winks and Terminator eyes
For the telescopic lenses to be wearable they'll also have to be custom-fitted to users' eyes. The researchers explored creating a digital model of a person's eyes by scanning them with a 3D scanner and then 3D printing the lenses
However, Ford's team found that the 3D printers they tried out weren't up to the task of creating these lenses. Most 3D printers are optimized to print in certain materials — usually a type of plastic, though there are 3D printers that print in all kinds of materials.
"That might be the direction some day, but we're not there yet," said Ford of 3D printing, though he added that he was excited by the possibility of 3D printing the lenses at some later point in the development cycle and that "one of these days that's going to be the case."
One of the research teams involved with the project is also working on developing a feature that would let users change the lenses' focus with a wink.
To do that, the researchers installed a camera in the eyeglasses that is directed at the wearer's eyes. The camera can detect when the user's eyes close: if both eyes close simultaneously, as in a blink, nothing would happen, but if a specific eye closes the glasses would process that as a command to change the eyeglass lenses' polarization as described above, thus changing the contact lenses' zoom.
If all this wasn’t enough to juggle, the researchers also have to think about what the finished telescopic lenses will look like. In the current iteration, (depicted above) the telescopic ring surrounds and partially covers the pupil, giving the eye a metallic, silvery look.
"We didn't worry about cosmetics," Ford said, adding, "I thought it looked pretty cool [like that]."
When the lenses become commercially available they'll probably have patterns or coloration on them to make them look like an organic eye. "We almost certainly would not have the lens looking like a Terminator eye," Ford joked.
The telescopic contact lenses were developed for people suffering from age-related macular degeneration, or AMD. People with this condition lose their central vision, though the peripheral vision usually remains intact, and regular corrective eyewear does nothing to fix it.
The telescopic lenses are similar in concept to telescopic eye implants that the FDA approved in 2010. However, Ford said that his team was interested in developing something less invasive.
The fact that these lenses will be removable also opens up their possible uses. Aside from AMD and other low vision problems, it's possible that the lenses could be used for a kind of 'super vision' in the future," Eric Tremblay, a researcher from the École Polytechnique Fédérale de Lausanne who is also working on the telescopic lenses, said in an email to TechNewsDaily.
Through DARPA, the Department of Defense funded the UCSD scientists' work. Tremblay said that the lenses "might be useful for military personnel. However, the bar for performance is much higher for enhanced vision, so this is a challenging direction for technology."