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Telescopic contact lense magnifies sight by 2.8

America’s Defense Advanced Research Projects Agency (DARPA) has been funding some pretty pertinent research – something that could completely revolutionise the way people operate, in and out of military operations.

Excited? Yeah, though so – their latest project is a telescopic contact lens that can magnify sight by 2.8 times.

Led by Joseph Ford of UC San Diego researchers have developed the aid ostensibly to help people suffering from macular degeneration – and now you obviously understand why a military research organisation would also be interested.

Check out this close up diagram of the lense:

lense

The lenses operate “by having two distinct surface areas. The centre allows light through as normal for regular vision”. Around the edge you can see a series of tiny aluminium mirrors that magnify the image before reflecting it onto the users’ retina.

In depth, the light that will be magnified enters the edge of the contact lens, is bounced around four times inside the lens using patterned aluminium mirrors, and then beamed to the edge of the retina at the back of your eyeball. “The mirrors magnify the image 2.8 times, but also correct for chromatic aberration, resulting in a surprisingly high fidelity image. To switch between normal and telescopic vision, the central (normal, unmagnified) region of the contact lens has a polarizing filter in front of it — and then the wearer equips a pair of 3D TV spectacles. By switching the polarizing state of the spectacles (a pair of active, liquid crystal Samsung 3D specs in this case), the user can choose between normal and magnified vision”.

To toggle and switch between the two lenses, the wearer of the contacts can toggle between them using polarising glasses, similar to those used for 3D films.

Have a look at these shocking examples of their effect on eye-sight.

“The most difficult part of the project was making the lens breathable,” Dr Tremblay told the BBC. “If you want to wear the lens for more than 30 minutes you need to make it breathable.”

“The fabrication tolerances are quite challenging because everything has to be so precise,” he said.

Clara Eaglen, eye health campaigns manager then spoke: “It is encouraging that innovative products such as these telescopic contact lenses are being developed, especially as they aim to make the most of a person’s existing vision,” she said. “”Anything that helps to maximise functioning vision is very important as this helps people with sight loss to regain some independence and get out and about again, helping to reduce isolation.”

The lenses may one day find their way into other areas as the research was being funded by Darpa, the research arm of the US military.

“They are not so concerned about macular degeneration,” he said. “They are concerned with super vision which is a much harder problem.

“That’s because the standard is much higher if you are trying to improve vision rather than helping someone whose eyesight has deteriorated,” he said.

Example

It is said to help restore sight to people with age-related macular degeneration. AMD damages the high-resolution fovea at the center of the retina, but generally the low-resolution outer region (perifovea) still works. Without the fovea, people with AMD can’t make out fine details, such as type on a page. These telescopic spectacles, lenses, and implants focus light onto this outer region, giving people with AMD the ability to make out these details.

Just a peek at the above images will depict just how much promise these lenses have, whether that’s helping those with eye disease and for military operations. At the moment, there are some current design limitations, however, namely the material used is not oxygen permeable, thus making long use incredibly uncomfortable.  The current telescopic contact lens is made out of PMMA, a gas-impermeable polymer that old, uncomfortable contact lenses used to be made of. To bring their lens to market, the researchers will need to switch over to rigid gas permeable (RGP) polymers, which modern, comfortable contact lenses are made from. While these telescopic lenses are obviously intended for people who suffer from AMD, there’s nothing to prevent a healthy person from wearing them and achieving better-than-human (superhuman?) vision.

Here’s what the Optical Society had to say:

The team tested their design both with computer modeling and by fabricating the lens. They also created a life-sized model eye that they used to capture images through their contact lens-eyeglasses system. In constructing the lens, researchers relied on a robust material commonly used in early contact lenses called polymethyl methacrylate (PMMA). The team needed that robustness because they had to place tiny grooves in the lens to correct for aberrant color caused by the lens’ shape, which is designed to conform to the human eye.

Tests showed that the magnified image quality through the contact lens was clear and provided a much larger field of view than other magnification approaches, but refinements are necessary before this proof-of-concept system could be used by consumers. The researchers report that the grooves used to correct color had the side effect of degrading image quality and contrast. These grooves also made the lens unwearable unless it is surrounded by a smooth, soft “skirt,” something commonly used with rigid contact lenses today. Finally, the robust material they used, PMMA, is not ideal for contact lenses because it is gas-impermeable and limits wear to short periods of time.

The team is currently pursuing a similar design that will still be switchable from normal to telescopic vision, but that will use gas-permeable materials and will correct aberrant color without the need for grooves to bend the light.

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