
Scratched glasses give perfect vision for any eyesight - ph0rque
http://www.newscientist.com/article/mg20827806.000-scratched-glasses-give-perfect-vision-for-any-eyesight.html
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bd
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".

[1] <http://www.xceedimaging.com/>

~~~
NathanKP
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.

~~~
eru
Strangely, the article also claims that it works with a cell-phone camera. How
does this fit with the brain adaption?

~~~
NathanKP
The article says:

 _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?

~~~
eru
Yes. Too bad they did not have a comparison to the example image in the
article.

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ggchappell
This is amazing.

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:

<http://www.opticsinfobase.org/abstract.cfm?URI=ol-35-18-3066>

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".

Wow.

~~~
mechanical_fish
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.

~~~
jcl
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.

<http://en.wikipedia.org/wiki/Pinhole_glasses>

It sounds like this new product has a similar set of advantages and drawbacks,
and maybe even works in a similar fashion.

~~~
davisp
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.

<http://en.wikipedia.org/wiki/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).

[ed: speling]

------
mey
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.

~~~
CUViper
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...

~~~
rlpb
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.

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blahedo
Hope for even better:

" _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.

~~~
jacquesm
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:

<http://wearcam.org/tetherless/node4.html>

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JonnieCache
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>

~~~
sp332
Even been to Disney World? I've read that the music varies by less than 3dB
(below the threshold of human noticing) throughout most of the park.
<http://dustincurtis.com/how-mr-q-manufactured-emotion.html>

~~~
JonnieCache
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.

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tokenadult
Whew! Some great comments here already. This article more than most needs a
reference to Peter Norvig's online reminder

<http://norvig.com/experiment-design.html>

about how to check out reports about supposed scientific findings to see if
the reports are really accurate.

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icegreentea
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?

~~~
eru
The first comment on that site (by Eric Kvaalen) says:

"Sounds similar to pinhole glasses. See
<http://en.wikipedia.org/wiki/Pinhole_glasses>

Pinhole glasses do work, and they work regardless of your level of myopia.

~~~
Groxx
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.

~~~
eru
You can make pinhole glasses with lots of holes, instead of just one. (Just
look at the picture in the Wikipedia article for an example.)

~~~
Groxx
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.

~~~
eru
The difference might not be as pronounced as you make it sound. You can e.g.
get diffraction effects just with a pinhole. (See
[http://en.wikipedia.org/wiki/Pinhole_camera#Selection_of_pin...](http://en.wikipedia.org/wiki/Pinhole_camera#Selection_of_pinhole_size))

------
bittersweet
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.

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dlnovell
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."

~~~
dlnovell
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.

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gokhan
I got a lazy eye. Contrary to the article headline, nothing can give perfect
vision for my eyesight.

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nileshtrivedi
Wow! This is seriously cool.

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.

~~~
camiller
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.

~~~
stan_rogers
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.

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ck2
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.

~~~
philwelch
What if your prescription changes?

~~~
jamii
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

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srean
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 ?

