Curiously, company site [1] seems to be already pretty old (all info points to 2006, domain was registered in 2004) and it describes pretty much the same technology.
So New Scientist got it wrong when telling startup was founded just now to commercialize it.
I wonder why it didn't catch on (if this approach is really so good). It does sound a bit "too good to be true".
Yes, the website has obviously been abandoned for years. It's strange that Zalevsky would even give them a link to it. It's also odd that, some 4-6 years after the founding of the company, they still have only tried their product on 12 people.
I imagine this is yet another theoretical result that turned out to have serious obstacles to a useful implementation. (See also all the "cures for cancer" that are constantly being announced.) Still, assuming it isn't some kind of fraud, the idea is amazing.
One possible problem with the technology is that even if it gives the wearer perfect eyesight, it seems to me that the lenses would appear frosted to others. So while you might be able to see through them just fine, they would look scratched to other people, and they wouldn't be able to see your eyes.
Additionally, it may not work with just anyone's eyes. For example, I remember a study in which scientists fitted a test subject with lenses that flipped the image upside down, and their brain started adjusting the image within a few weeks. Also I know a person who wears two different contacts, one in their left eye for far sight, and another in their right eye for near sight, and she says that this allows her to see both near and far just fine.
But not everyone can do this without getting a headache, eye strain, etc, and from the article it appears that part of the operation is that one's brain has to adjust to process the image. It may be that this scratched groove system isn't quite compatible with everyone. And even if one does manage to retrain their brain to the new system, what happens when you take the glasses off? In the study I mentioned earlier, after the test subject retrained their brain to see correctly while wearing lenses that turned things upside down, when they took the glasses off everything appeared upside down to them.
So the glasses might have a similar effect if they rely as heavily on brain adaptation as I suspect they do.
the interference pattern tends to cancel out some of the light passing through the lens, which reduces the contrast of images viewed through it.
The example image also shows this effect.
The claim is that:
the brain adapts to and minimises the reduced contrast within a few seconds.
My point was that this adaptation may not work for everyone or may not be comfortable. Also when the glasses are taken off do your eyes have to readjust to normal contrast?
It seems to me that the given explanation ("patterns of both constructive and destructive interference") would depend strongly on the exact frequency of the light. So maybe it is not correctly stated.
However, the basic claim seems accurate. Here is Zalevsky's paper:
You have to pay to get the full text, but the abstract says:
> This technology is capable of simultaneously correcting all refractive errors, such as myopia, hyperopia, presbyopia, regular/irregular astigmatism, as well as their combinations.
My goodness.
Curiously, the abstract suggests that this idea is "designed to employ neural adaptation processes". It also says that the effect "is achieved by exploiting the capacity of the visual system for adaptation to contrast".
Agreed, I can't figure out how this can work for all wavelengths. But, then, I can't figure out how it would work at all, so what do I know? Perhaps this calls for a trip to the MIT library.
One wonders if too much reliance on "adaptations of the visual system" is going to cause problems. For example, will you wind up training your brain in such a fashion that you'll need several hours or days of retraining to see with your glasses off? Visual processing is famously plastic, but one wonders what the timescale of the plasticity is.
Right now, you can get opaque black plastic glasses with an array of pinholes. These work to correct a variety of focusing problems, since pinhole cameras have an infinite depth of field. The drawback is that pinholes let in very little light, so although the image is in focus, it is very dim. And, of course, the image between the pinholes is not as good as it is near the pinholes.
I don't have access to the full text article so I can't say for certain but the article makes it sound like the effect is accomplished in a fashion similar to phase contrast microscopy.
The basic concept of phase contrast is that certain objects (notably, monolayers of biological specimens) don't greatly affect the amplitude of light passing through them. IOW, viewed under "normal" optics, they would appear transparent.
On the other hand it was noticed that these objects do cause the phase of light to shift as it passes through the specimens. The basic idea is that you create a system that has light passing through the specimen in two paths. The major light path is dimmed and accelerated by half a wavelength. This gives us a situation of theoretically perfect destructive interference at the point of observation. When the reference light waves pass through a phase object, it changes the phase of the light and introduces perturbances to the completely destructive interference which results in an observable image of the specimen.
The reason these glasses remind me of phase contrast is the concentric circles milled to specific depths and widths (which is one of two important pieces of a phase contrast microscope, the objective). Also, the article describes the effects based in terms of phase:
The rings shift the phase of the light waves passing
through the lens, leading to patterns of both
constructive and destructive interference. Using a
computer model to calculate how changes in the diameter
and position of the rings alter the pattern, Zalevsky
came up with a design that creates a channel of
constructive interference perpendicular to the lens
through each of the 25 structures. Within these
channels, light from both near and distant objects is
in perfect focus.
I never took the optics courses in school so I'm not able to connect how the phase properties are leveraged for focus. The only thing that comes to mind is that they're using phase differences to selectively destruct out of focus rays and reinforcing in focus rays (hand wavy factor: 8.6 of 10).
Elementary yet interesting. I just "constructed" a pinhole by curling my index finger in my thumb, and could read letters on this page. At the same range without wearing contacts or glasses, I am unable to separate words. Only lines of text.
I use glasses in the evening and contacts in the morning, so the dimming could perhaps be beneficial for circadian rhythms if I need to use a computer, although I recognize that probably has more to do with the spectrum of light than the intensity.
Extraordinary claims require extraordinary evidence though, so to be perfectly honest, I'd like to see a good number of people wearing these new lenses before concluding that they are as amazing as they are being presented as being.
Currently my brain is wired to have focus one on area at a time. It must be a trip to have an entire field of view in focus all at the same time. Especially if you are looking at something in the near-field and the far-field is two wildly separated visual images.
In a lot of video games, the entire scene is in focus, presumably because the developers can't know where you're actually looking. In that context, it doesn't feel weird at all (though I wonder if that's part of why some people get sick watching 3D games). Anyway, I don't know if that would translate to real life, since a 2D monitor doesn't give you any stereopsis hints, but it seems not too much of a stretch...
When I look at my screen, only a part of it is in focus. The computer doesn't need to know where I'm looking; my eyes are blurring those other bits for me.
Not really, whenever you're looking at a landscape far away (focussing at infinity) everything is in focus. In fact, any situation where everything in front of you is equidistant from your eyes will mimic this everything is in focus situation.
Not so much. An enormous field of view is in focus on a sunny day, and you can see far more in focus by looking through a pinhole. Or there's the video game argument mentioned by CUViper.
Of course, since we see in stereo, images will still only be aligned when we're looking at them with both eyes. And our eyes really only see detail in a tiny area (a few degrees). Having everything in focus is a negligible gain over having all distances you look at in focus.
For people with fairly good vision, the brain is already good at doing synthesis, so you have a whole scene effectively "available" to you, even if your eye can't simultaneously focus on all of it--- as you scan across a scene, your iris is constantly opening/closing, and the lens is changing focal depths, but you perceive it as effectively one scene. Sort of a fancy real-time version of HDR plus focus aggregation.
It's possible that being able to actually see it simultaneously will make a big difference, but it's possible that much of it won't be that noticeable, because it'll just be implementing in hardware what we can already composite in "software" fairly well. Although, I can imagine one difference might be at wildly different focus depths, e.g. when I'm sitting at my desk, I don't simultaneously perceive my monitor and the tree 100ft away out the window as being in focus. It's hard to say, because there's also a center-of-vision / peripheral-vision distinction involved there, which would still exist even if all distances were simultaneously in focus.
I'm wondering if this technology might make it easier to perform certain tasks. For example, consider the various kinds of security or military work that essentially require someone to give attention simultaneously to a large area. (And I imagine there are other examples ....)
"Fixed in a pair of glasses, the lenses would not move as the eye looked in different directions, so the focusing effect would be lost in the regions between the circles. But Zalevsky says that the eye learns to fill in the gaps as it moves from one engraved structure to another, generating a continuous effect."
This implies to me that once they cleverly figure out how to embed this tech in something like a contact lens, it wouldn't have to "fill in the gaps" and would grant perfect vision in the full vision field. Wild.
The brain is extremely flexible in the inputs that it will accept, but one problem of such neural re-wiring is that you will have a splitting headache the moment you go back to 'normal' inputs.
Read about this mind-blowing experiment, where vision was inverted:
> This implies to me that once they cleverly figure out how to embed this tech in something like a contact lens, it wouldn't have to "fill in the gaps" and would grant perfect vision in the full vision field.
Maybe. I have my doubts, though. The abstract to Zalevsky's paper (see my comment on this HN post) ends as follows:
> This is achieved by exploiting the capacity of the visual system for adaptation to contrast as well as its capability of creating a coherent continuous visual field out of discrete lines of sight.
So simply focusing light on the retina is apparently not the goal. Rather, it appears that the brain is being sent unusual signals, which it is nonetheless capable of interpreting. In other words, there isn't just optics going on here; there is also some interesting neurology.
Now please apply this to speaker drivers so we can have huge rooms filled with flat 110dB sound, with consistent SPL across the spectrum no matter the listeners position relative to the speaker :)
Seriously, it does remind me a bit of Turbosound's polyhorn system, see page 8 here: http://bit.ly/dxEYrB
Yeah but its not at 110db on average is it? And disneys background music is hardly precision engineered in the first place.
I'm talking more about music venues, and the dream of being able to hear the performance as clearly at the side of the room as in the exact middle, or wherever the engineer has put the "sweet spot," which is analogous to focal length but not exactly the same concept.
I'm a bit confused. In order for everything to appears perfectly focused, doesn't the glasses have to generate light rays that are just out of focus enough so your lens refocuses it correctly? So the patterns would have to be calibrated for your degree of myopia or whatever?
But pinhole glasses work by passing all light through a single, tiny hole, which doesn't allow scattering of light from a single source because they must all pass through that point. If you're left with nothing but a single ray from each point, it'll be in focus forever until something disturbs it. This lens sounds entirely different.
Which is still the same principle. You're mechanically restricting the cone of light from each point of what you're looking at, where a lens will change the direction of light in that cone.
> ... doesn't the glasses have to generate light rays that are just out of focus enough so your lens refocuses it correctly?
I would think so. However, it looks like the idea is not just to focus the light. There's some interesting neurology going on, too. (See my other comments to this post.)
I have pretty bad eye-sight and experienced something like this when I was younger, although I don't know if it's the same principle. I had on swimming goggles and the moment I went underwater I had perfect vision in both eyes.
My mother in law is an optometrist and I sent her the link - she doesn't seem too impressed:
"The immediate problem I see with this is that people can already see with their distance correction anything that is 33cm (83.82")(6.9 ') from their eyes to infinity. The problem that bifocals fix is the distance from 20" to the eyes or near vision! I don't know if this person is over 40 or not, but if so he should realize this. This type of technology is similar to what a progressive or "no-line" bifocal does at present."
Just noticed her math is off a bit!!! haha. I guess she applied 2.54 the wrong way - ~1 foot instead of 7 feet. (I hope she doesn't do that to her patients!) I wonder if that changes her opinion much. I guess 13 inches is close enough a distance to read from so maybe this is as awesome as it sounds afterall.
Speaking of augmenting our sensory capabilities, has there ever been any work done on making hearing a voluntary sense? Always-on hearing had some evolutionary advantage in the past but it may be an interesting experiment to put this in one's own control.
According to my wife men have this capability built in...
Kidding aside, really good earplugs, the kind they wear where really loud machinery is in operation, effectively gives you that. Get the foam one that you roll between your fingers to squish them and then they expand to fill your ear canal. They block out a lot of noise.
They block out too much noise in a lot of cases (especially those bullet-shaped orange jobbies with the 33dB attenuation). Without competing environmental noise, your own body noise (and there is a seriously big whack of that) becomes an enormous distraction. I loved them when I worked a hangar line around jet engines, but when trying them to get a bit of quiet in the office, I found that my heartbeat, my joints, the impact of my fingers on the keyboard and the sloshing of blood through the carotid arteries (which are way too close to the ears) constituted a distraction about on par with someone operating a jackhammer outside the window. Now, if there actually had been a jackhammer, the attenuation would have been about right. I found that the much less efficient silicon plugs were better for blocking low-level noise -- they didn't force the AGC circuits to max gain.
I saw something on CBS news this morning about how they can now put a kind of contact lens INSIDE your eyes. And the woman they used as an example was able to see again only seconds after the surgery was finished. It was amazing.
The surgery is easily reversible without leaving permanent damage. That's the main advantage it has over laser surgery. Its not exactly a contact lenses though, its a ring of plastic that stretches your cornea. It also only works for low prescriptions
Isnt that a Fresnel lens ?
http://en.wikipedia.org/wiki/Fresnel_lens
They have been around for a while. I remember some plastic ones come free with books that have very fine print.
So was the novelty of it all putting them on eye glasses ?
So New Scientist got it wrong when telling startup was founded just now to commercialize it.
I wonder why it didn't catch on (if this approach is really so good). It does sound a bit "too good to be true".
[1] http://www.xceedimaging.com/