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Goodbye Bifocals — Electronic Glasses Change Focus

Posted by CmdrTaco on from the see-what-i-see dept.

kkleiner writes "Move over Ben Franklin, we finally have a replacement for bifocals. Virginia-based Pixel Optics has developed a composite lens that can change the range of focus electronically. The emPower! glasses were created in cooperation with Panasonic Healthcare, and allow you to switch between long distance and short distance vision in a split second. Rather than having a lens divided into two sections, emPower! uses an LCD overlay that can change the focal length of the glasses via electric current. When the LCD layer is off, your lenses are good for intermediate/long distances. Turn the LCD layer on, and a section of the lens is suddenly magnifying close-up images – perfect for reading."

11 of 166 comments (clear)

  1. How do you switch? by bradgoodman · · Score: 3, Insightful

    How do you switch between the two? With a mechanical switch? Seems to me like that would be more difficult than just adjusting your gaze between the two lenses, like with normal bifocals...

    1. Re:How do you switch? by NEDHead · · Score: 3, Funny

      The 16K implanted brain probes sense your intent and adjust accordingly

    2. Re:How do you switch? by OolimPhon · · Score: 3, Insightful

      Idiots. They have no idea how people of bifocals use them, do they?

      I have mine set up so that the line between the separately-focused halves is exactly lined up with the top of my monitor - and the focus of the lower half is arm's length, which is just right for screen work and still acceptable for reading.

      All I have to do is rotate my eyeball up to see perfectly the guy at the facing desk or rotate it downwards to see the code on my screen perfectly, all without moving my head.

      Why on earth would I want to tap my glasses everytime I look up or down?

    3. Re:How do you switch? by mcgrew · · Score: 4, Informative

      Not as nifty as my CrystaLens. Its focus accomodates, exactly like the eye of a young person does (at least from the user's perspective, even if the mechanism is different).

      Over the life of your eyeballs a CrystaLens is probably cheaper, too. The surgery is ~$7k per eye, but you only need it once and your eyes focus for the rest of your life, no glasses needed (at least, if your surgeon is competent). If you have cataracts, insurance will pay all but about $1k per eye. You can get cataracts from steroid eyedrops.

      The downsides are that the CrystaLens is a surgical implant; they stick a neeedle in your eye, shoot ultrasound down the needle to turn your eye's lens to mush, suck the mush out through the needle, and insert the implant in its place. Most patients don't require any external lenses like glasses or contacts after the surgery, but some do (Evil-X is wearing bifocals, but I think that was a bad choice of surgeons), but most don't have the better than 20/20 vision I got, although something like 98% have better than 20/25. Glasses give better vision for most patients.

      (Journal of the procedure here)

      --
      Free Martian Whores!
  2. Perfect for by Archangel+Michael · · Score: 3, Insightful

    breaking and expensive replacements.

    Sorry, but I like my analog glasses just fine. I'd hate to have to constantly flip between LCD mode and normal mode. That would drive me nuts more than my graduated glasses are now.

    Not everything is better digitally.

    --
    Agent K: A *person* is smart. People are dumb, stupid, panicky animals, and you know it.
    1. Re:Perfect for by jayme0227 · · Score: 4, Insightful

      This is interesting technology, but just screams "Solution looking for a problem."

      --
      But then I realized the cable was blue, so I only gave it one star. I hate blue.
  3. Meh. by msauve · · Score: 5, Interesting

    The Superfocus ones look much more interesting (continuously variable focus), and are considerably cheaper, too (~$700). Con: they're only available with circular lenses. Pro: they're hyped by Penn Jillette.

    --
    "National Security is the chief cause of national insecurity." - Celine's First Law
  4. Lots of naysayers... by bjk002 · · Score: 3, Insightful

    on this thread, but I would think a bunch of nerds would appreciate the technological triumph, not belabor the deficiencies / hurdles that remain.

    Perhaps the price-point is ridiculous, but as any professionals know the price drops with economies of scale.

    From my perspective, this represents a viable first step toward the elimination of glasses all together. I'm thinking contact lenses with micro generators like this. OK, maybe not today, but tomorrow?

    --
    Opinion:=TMyOpinion.Create(Me);
  5. Feeling old by kabloom · · Score: 4, Insightful

    This probably doesn't solve the main problem of bifocals, which is that people who need to wear them for the first time will still feel old. Graded lenses without the line that's visible to other people didn't solve that problem, and technologically cool LCD glasses won't either.

  6. How does that work? I don't even ... by goodmanj · · Score: 4, Interesting

    OK, here's me. I'm a physics professor. I don't do optoelectronics research, but I do teach optics sometimes. I'm pretty savvy about electricity, magnetism, optics, chemistry, etc. I know how LCDs work, in detail.

    WILL SOMEONE PLEASE EXPLAIN HOW THESE SUCKERS WORK? IT'S DRIVING ME CRAZY!

    How the hell do you change the index of refraction of a material for *both polarizations* simultaneously? Liquid crystals are birefringent, but that's not enough to make a *lens*.

    Also, what does it say about Slashdot and the rest of the geek community websites reporting this story that nobody else is asking this question? Aren't you guys supposed to be curious about how things work, or have you become like the rest of humanity, taking technology to be a miracle handed down from on high?

    I'm baffled on both counts.

  7. Re:How does that work? I don't even ... by goodmanj · · Score: 4, Informative

    Thanks to people who linked to the patent, I think I understand what's going on now. My guess was mostly right...

    A liquid crystal material consists of long rod-shaped molecules. They have the funny property that light passes through them at a different speed depending on whether the light is polarized parallel to or perpendicular to the axis of the rods. This is called "birefringence".

    Normally, if a thin layer of liquid crystal is sandwiched between two glass plates, the molecules line up parallel to the plates. However, if you put a voltage across the plates, the molecules line up end-to-end, perpendicular to the plates.

    Therefore, applying a voltage effectively changes the speed of light passing through the liquid crystal. Glass optics work because the speed of light in glass is slower than in air: the difference in speed causes the light to be bent. Since liquid crystals can *change* their speed of light electrically, if you create a LC layer with exactly the right shape you can make a "lens" that vanishes when you switch off the voltage.

    There's a lot of technical details (rather than creating a classical lens, the liquid crystals impersonate a Fresnel lens, requiring specific shapes and voltages for the electrodes) but that's the gist of it.

    Where I was being led astray was by the effect liquid crystals have on *rotating the polarization* of light. This is a crucial part of understanding how LCD monitors work, but after thinking about it I realize that when used in these glasses, the liquid crystal will indeed rotate the polarization, but that's not something the human eye can detect.