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Goodbye Bifocals — Electronic Glasses Change Focus
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."
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...
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.
Yes let us bid goodbye to a foolproof, established, and market proven tech because something new has come out.
Taco...Come now, "Welcome the new Bifocals," would have been much more appropriate.
Really, I know what I'm doing...Ohhhh, look at the shiny buttons!
Once these are cheaper then I might switch, but for now the $60 progressives that I bought from http://www.zennioptical.com/ are working just fine thanks.
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
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);
If you're doing an 8-hour work day, get full-sized reading glasses, and switch glasses when you're leaving your desk. Or you could try progressive lenses.
Twenty years ago, it was much easier to fix this problem for my supervisor, who was about 60 and constantly switching glasses. We were using the Sun NeWS windowing system, so we just told his screen to use a 25-point font, everything got bigger, and he was happy. On the other hand, today you can get a much bigger screen, and as long as you're not using Windows, it's not too hard to change font sizes.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Getting first post trumps reading the article I guess.
No sig today...
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.
If you're going to add whiz-bang technology to glasses, why not go the full monty and add a 3d polarized mode for movie-going four-eyeses? Why not throw in a "sunglasses mode" while you're at it? For $1200, I'd expect more features.
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.
Well, keep in mind that 20/20 is not 'perfect' eyesight. it means that you should be able to see thing that are 20' like they are 20' away. 30/20 might be better. 200/20 would put you in the realm of super hero. (I might have the numbers reversed. It has been a while since I looked this up.) So, perticularly when talking about looking at a monitor, 20/20 doesn't even come into play.
That being said, there are a lot of people that think they have better eyesight than they do. Sometimes this is because of denial, sometimes it is because they got a crappy eye exam that told them wrong, and sometimes they remember being told that they had 20/20 vision 25 years ago, and it hasn't struck them that their vision might have gotten worse.
I know that I was told I had 20/20 vision when there was no doubt in my mind that my vision was horrible. For a long time, I didn't even realize that my vision was bad. When things change gradually enough, you often don't notice anything changed at all. When I did finally get glasses, it was amazing.
I did end up getting laser surgery, and I am glad I did. Not only were glasses expensive, but they tended to scratch, fog up, and get dirty. All of these things lead to worse vision for me. Having glasses is a pain in the butt. Yes, one can get used to them, but it is still a fair amount of trouble.
My wife's vision on the other hand, was saved by laser surgery. By 28, she was 'legally blind'. She could see reasonable well with glasses, but without them, just getting around an unfamiliar room was a chore. The worst part was that like clockwork, every year when her eyes were tested, they would be another half point worse. I doubt she would still be able to see today, even with glasses, if she had not had surgery. She got surgery almost 10 years ago, and she is just now starting to notice slightly worse eyesight. I don't know why having glasses was making her eyesight worse, but it seems they were.
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.