|Shane, from Aspex, and Dawn, from PixelOptics, demontrate||emPower glasses|
Glasses that change their focus with the tilt of your head, or by a touch on the temple? Lenses with embedded liquid crystals in the reading zone that can change power with a touch? I had an opportunity to “test wear” a pre-production pair of these high-tech glasses by PixelOptics that is due be on the market this fall. Is this the wave of the future?
First, I was unable to find any technical information about the lens, so what follows is information I gleaned from the company representative and my own educated guesses. The basic principle behind the changeable focus is an oval liquid crystal wafer embedded in the lens in the near vision zone. Applying a current to the wafer changes its index of refraction, which changes the effective power of the wafer.
For my non-optical trained readers, “index of refraction” is a principle of physics that allows glasses to work by slowing down light in the lens, thereby allowing the curves of the lens to bend the light so that it can improve your vision. Think of two bowls, one filled with water, and the other jello. Now, using the same amount of pressure, push a straw through to the bottom of the bowls. It takes longer to push the straw through the jello, because it is denser. In optics, the straw in water represents a beam of light passing through air, and the straw in jello is like light passing through a lens. OK, enough of that – how do they work in the real world?
The lens appears to be a hybrid in several aspects. First, it is a laminated lens, with the front of the lens having a variable curve similar to a progressive lens, then the wafer, and then the back of the lens where the power is ground. With the near vision mode off, it feels very much like a single-vision distance lens, with almost no distortion. I touched the temple to activate the liquid crystals, and as if by magic, I could see up close! There was a very decent sized reading zone, larger than progressive lenses offer. Fabulous distance viewing, better reading – where’s the downside?
Well, even though the lens has a modified progressive design on the front, I could not find any useful intermediate viewing area. Computer use? Uh-uh. Ditto with counter-top or “shopping” distance. You have to move your head to the distance at which those areas will come into focus, just like old bifocals. Speaking of computers, I found that if there is an area of contrast on the screen – say, like the white “page” with blue borders on which I’m typing this article – there is a very disconcerting amount of “flare” (a highly distorted) at the junction of the liquid crystal wafer and the rest of the lens. It makes me wonder what they’d be like to drive in at night with on-coming headlights.
Finally – and this may just be a nit-picking optician who is trained to look for optical aberrations – but when looking through the unactivated the “almost invisible” liquid crystal wafer is vaguely visible. Much like a faint smudge, it’s likely most people would never notice it’s there.
Final verdict? A very intriguing concept, probably not quite ready for prime time, but a must-have for early adapter tech geeks. For more information, leave me your questions in the Comments area. You can also access their website at www.LifeActivated.com, or watch this video. Be sure to stay tuned, I’m sure more ground-breaking innovations such as this will be forthcoming!
Follow me on Twitter at @BillGregoryLDO
Check out my Facebook page at Bill Gregory Optician
Copyright © 2011 All Rights Reserved