# Optical Forums > Ophthalmic Optics >  tinkering with polarization

## Jeff Trail

probably one for Darryl or CEO..

 BUT I know you use crystaline Iodine in the polar sheet but can you have a "clear" version of a polar sheet? I know that it would make orentation (brewsters law) of the sheet hard to maintian but I was wondering about how hard it would to make it..I also know all the rest of the basics of "why" it wouldn't work in RX etc., etc...it's the question in the following paragraph I am looking to hear about
  I know that the degree of depolarization lock steps with the "thickness" of the sheet which relates to the "shade" darkness of the lens and the thicker the better the polarized lens works but here was something I was thinking about...say I had a clear polarized sheet and was able to chemically bond the iodine crystals to a transitional chemical so indoor it would be clear but when going out doors instead of a "comfort" tint we get now from transitions when the chemical activated it would darken the clear polar sheet so you would get a TRUE transition sunglass that worked indoors and out? 

   Just wondering?...NO BODY BETTER STEAL MY IDEA.. :Rolleyes:  I put this idea to a number of people (including my corp. lawyer..so don't try to be sneaky) ..I am trying to find a chemical engineer who might want to tinker with this as well..anyone know any one who might like to tinker? 

Jeff"Nikola Tesla is my hero" Trail
     OR if you prefer
Jeff"I just love to play Mr. Wizard" Trail

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## shanbaum

Jeff, you could tell a thousand lawyers, and it wouldn't protect an idea you discuss openly.

As far as "clear polarizers" are concerned, I think Darryl posted something about this once upon a time, pointing out that these are filters, and work by absorbing some of the light passing through them.  That means, an image viewed through such a filter is going to be dimmer than it would be when viewed without the filter.

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## chip anderson

Been bringing this up for years, amoung other things, I could have as much light as I want to paint and match artificial eyes without glare washing the color out.  Surgeons could benefit for same.

I have seen near clear polarized filters in micorscopes and the like but they still tell me it can't  be done in spectacles.

Chip

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## Jeff Trail

> *chip anderson said:* 
> Been bringing this up for years, amoung other things, I could have as much light as I want to paint and match artificial eyes without glare washing the color out.  Surgeons could benefit for same.
> 
> I have seen near clear polarized filters in micorscopes and the like but they still tell me it can't  be done in spectacles.
> 
> Chip



   Chip, 

    The density of the sheet (which coincides to the darkness) has a direct effect on the amount of polarazation..that is why a darker polarized lens works better than a grade A polarized lens, or in the case of the microscope you mentioned to have a low ambient light condition in an enclosed area, not the wide out doors like I am interested in..what I was wondering is that if you had a thicker sheet but clear and figured a way to bond it chemically to the "transition" material than in doors it would be clear but as the chemical activated outdoors it would make it darker ..taking a thinner sheet lens and just adding tint does not improve the de-polarazation that the lens can do.. so I was wondering if you had a thicker sheet (density) and had it embibed with the transitional chemical if it would work :-) I guess I'm getting to the point of "is it a given that the more dense the sheet does it have the side effect of being darker" or can you "adjust the sheet in density EVEN if clear?"

     Robert,

     I know about the law part already, that part was more in "jest" than anything else.. I hope this thread does NOT get side tracked into that area (maybe I should edit that part out..ya think?).. also, I knew from basic theoretical optics anything we place infront of the eye has a certian degree of absorption as well as distortion and ray diviation, BUT I could live with a little bit of lack of "brightness" if a combination that worked could be figured out.. you could always add a slight hint of a yellowish cast to increase contrast in the lens and a AR stack..

     I was just curious if anyone tried it or what they thought about the idea :-)

Jeff"still holding out for the lottery" Trail

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## dfisher

Just a thought...

A thicker polarizing layer might produce a visual effect like a micro-frenel prism.  Lots of visible micro lines.

What if ? you could do the transitions layer on the polarizing screen before the lens was laminated?

.

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## Jeff Trail

> *dfisher said:* 
> Just a thought...
> 
> A thicker polarizing layer might produce a visual effect like a micro-frenel prism.  Lots of visible micro lines.
> 
> What if ? you could do the transitions layer on the polarizing screen before the lens was laminated?
> 
> .



   Hmm.. but that needs some deeper thought, if the layer made a visual effect like press on prism.. than the question that comes to mind is "why would you see that same effect in ANY of the polarized lens?" .. I'm not saying thickness in say mm of thickness but say if you had a Nupolar from Younger (I do love that product BTW) and had the SAME thickness as in that lens (the darker version) BUT without the color.. and than bonded the two some how would that work? ... Now I wouldn't want the "lens" imbibed with it but an actually mixture of the two catalyst at the same place is what I'm getting at...
     I just wish an optical engineer or someone famialr with the process would jump in here and enlighten me on the exact stack in the sheet..;) 

    Already a company out there that makes a "transition" lens with a polar shield .. I don't much like it.. I just wanted to see if it was possible to have an polar shield that could be clear and than be "activated" to get it dark ...

    Oh well, maybe I'll still get it figured out on my own.. just thought maybe someone else that already had knowledge of the actual sheet could tell me if I was full of beans or "hey it might work IF yada yada"

     I was even thinking that you have a few companies now that are using a lamenation system (J&J etc.,etc. on the outside surface) so if you placed (lamenated) the thin layer say in a 1.60 wafer (clear polar sheet with the transitions chemical) on the INSIDE of the lens surface would the movement of the shield from the outside curve and having to deal with the full thickness of the optical lens interferring with distortion and absorption and axial chromatisim .. what if that was placed on the ocular side would that increase the quality of the optics of the lens?

     Oh well, more "questions" than answers, maybe this is one thing I shouldn't started tinkering with.. :Rolleyes:  

Jeff "keep this up I'll lose my official Mr. Wizard club badge" Trail

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## Darryl Meister

Yeah, I tried to find my post that explained clear polarized filters in detail, but I was not able to. (I did find another post that contains some good information on polarized lenses, which I bumped back up.)

The problem is really very simple when you think about it... What does a Polaroid filter do? Specifically, it aborbs waves of light vibrating along the desired plane (for instance, the horizontal plane). I'll provide some background, first...

Waves of light reflected off diffuse surfaces or emitted from common light sources, like the sun and light bulbs, vibrate at random orientations as they travel away from their source. This light is _non-polarized_; some of the waves will be vibrating through the horizontal plane, some through the vertical plane, and some through oblique planes, in between the two. However, when light is reflected off certain relatively smooth surfaces, such as pavement or water, much of the reflected light is confined to the _horizontal_ plane of vibration. At a certain angle to these surfaces, known as _Brewster's angle_, the waves of light are completely confined to the horizontal plane. This reflected light is generally perceived as troublesome _glare_.

Now, since the glare reflected off of these surfaces is generally confined to the horizontal plane, a filter that eliminates waves of light vibrating in the horizontal plane will eliminate this glare. A sunglass lens, however, reduces _all_ light, including waves of light vibrating in the vertical plane. The only way a sunglass lens can completely eliminate reflected glare, which is confined to the horizontal plane, is for it to completely eliminate all light (not terribly feasible). Fortunately, a Polaroid filter virtually eliminates waves of light vibrating in one plane. (See the other post for a complete discussion of how this is achieved.) Now, since polarized sunglasses are generally worn to eliminate reflected glare, they are oriented to absorb waves of light vibrating in the horizontal plane.

Because a basic Polaroid filter absorbs light vibrating in the horizontal plane, some of the light is lost by necessity. After all, if it doesn't eliminate this glare, it doesn't serve much use. ;) Since a filter that absorbs _any_ light will not appear perfectly clear, a basic Polaroid filter cannot appear clear, either. The more light a filter absorbs, the more grey it will appear. Furthermore, _all_ waves of light, even those vibrating through oblique planes, can be resolved into horizontal and vertical components (planes). (Like a prism at axis 45 can be converted into horizontal and vertical prisms...) Consequently, _half_ of _all_ light is vibrating through a horizontal plane, while the other half is vibrating through a vertical plane. This means that a perfect Polaroid filter will actually absorb 50% of the light passing through it (i.e., all of the horizontal light). This also means that, while a Polaroid filter can be tinted to absorb _more_ than 50% of the incident light, it cannot absorb _less_ than 50% and still completely eliminate reflected glare.

Best regards,
Darryl

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## Jeff Trail

> *Darryl Meister said:* 
> The problem is really very simple when you think about it... What does a Polaroid filter do? Specifically, it aborbs waves of light vibrating along the desired plane (for instance, the horizontal plane). I'll provide some background, first...
> 
>  This means that a perfect Polaroid filter will actually absorb 50% of the light passing through it (i.e., all of the horizontal light). This also means that, while a Polaroid filter can be tinted to absorb _more_ than 50% of the incident light, it cannot absorb _less_ than 50% and still completely eliminate reflected glare.



  Thanks Darryl,

     BUT I already knew the majority of the stuff you listed, I don't want you to think you wasted your time, and I think I maybe still "missing" something here on my brain has gone south.. but it is the last line up there "while a Polaroid filter can be tinted to absorb "more" than 50% of the incident light, it cannot absorb "less" than 50% and still completely eliminate reflected glare." that is going to tie to my original question.. indoors I would NOT care about the elimination of glare..so having a clear or nearly virtually a clear shield would be acceptable ..BUT if taking my question and finding a way to "flood" the shield with a chemical reactive substance (transitional) so when you went outdoors and it was activated than you would get the "darkness" in the shield and would increase the amount of absorption (?)..depending on the type of chemical reaction, ambient or UV activated even get a varied degree of darkness based on the physical conditions .. i.e. brighter day more darker if it was ambient activated :-) 
  Here is where I think YOU are coming from using iodine a nonmetallic halogen element in a polar sheet it has a dark crystallized matrix and the denser (darker) the matrix the higher the degree of absorption (and blocking) .. right so far? .. WELL what I was getting at was could you actually have a polar sheet with the properties where it could have an "adjustable" degree of color density..ie. clear indoors in a relaxed state and dark outdoors in an activated state and the "transitional" chemical as the catalyst? "Clear" indoors maybe a minomer since it physically would have some absortion by its nature...say a slight hue of 10%...
   I must be missing a "link" somewhere in the process..Like I said I knew basically every thing you mentioned (still don't consider it as a waste of your time others who read this thread may not have known) I knew the darker the iodine matrix the higher the degree of absorption.. but what I was wondering is if you could mix clear and dark by using that other element..I might be missing something, like it is the "actual" crystal that passes the ray (simplified I know) that HAS to be dark to get the effect and NOT the actual "darkness" of the element "beside" the crystal?(in this case my "transition" element).. is that the problem I'm missing?
    Sometimes us "hard headed" lab rats need to have it pounded into our little brains  :Rolleyes: 

    Both threads was appreciated but I think I'm getting there.. Hopefully everyone else is gleaming some information through this "filtered" thread as well  :Rolleyes: 

thanks ...

Jeff "just a thick headed lab rat" Trail

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## Lee Prewitt

Jeff,

What I think you are driving at is a photoreactive iodine crystal that would change its polarization effect according to the light conditions present, right?  That would be very cool indeed.

BTW, I concur with you on the iodine. Its not the sheet's thickness per say but how dense the iodine is within the matrix.  The polyvinyl is simply the substrate used. Learned this when I worked for Hobie Sunglasses and talking with the factories in Japan that produced the film.  They had a really cool NiteVision lens.  It was very light but a weak polarizer.  Marketed for Nite driving and office work.

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## Jeff Trail

> *Lee Prewitt said:* 
> Jeff,
> 
> What I think you are driving at is a photoreactive iodine crystal that would change its polarization effect according to the light conditions present, right?  That would be very cool indeed.



Lee,

   OH someone see's what my rambling was trying to convey
;) NOW onward and upward..Thanks to Jim Shafer (Transitions) helping me a long as well with this tid bit of information  Jim wrote to me:




> The photochromic reaction is how the silver halide chemistry works. The halide salts fall away and the silver pulls together to form a trellis like configuration causing the color that creates "darkness".
> 
> With organic systems, the molecules absorb light and use the energy to swell up larger, pivot on their oxygen bond and open up like one of our communication satellites. As the energy burns off the molecule collapses back and reabsorbs the light to kick off another reaction. This reaction is very fast and is governed by how intense the light is. More energy the faster the reaction. 
> 
> What this causes is the need for a media that allows the reaction to occur, it needs room to breathe so to speak but yet still have constraints. You have runaway reactions that either activate and stay dark or take forever to fade back, or react funny in hot or cold weather.


   So that lead me off to this line of research The silver halide in photographic film is in the form of small (1.0 to 1.5 microns in diameter) crystals which are suspended in the gelatin of the film emulsion. The atoms in the crystal are arranged in a cubic lattice and each crystal contains many point defects, where a silver ion is displaced and is free to move through the crystal. Now since silver halide is "defective" (in terms) crystal why "couldn't" you figure a way to lay in the iodine crystal so it would biuld like a lattice work?
     The three silver halides used in photographic film are silver bromide, silver chloride, and silver iodide. These crystals are differently sensitive to light. To take a photograph, one needs film that is sensitive to the visible part of light, which ranges in wavelength from about 4000 angstroms (blue light, high energy) to 7000 angstroms (red light, lower energy). Silver chloride crystals are white and therefore do not absorb light appreciably in the visible range. Silver bromide crystals are a pale yellow and absorb light up to 4,900 angstroms (blue light). Silver iodide crystals absorb even more visible light, but are not as well suited for photography, because the crystal structure puts the silver ions away from the surface, where they can't be developed. I know it is "basic" photography elements but the "transitions" seem to be working basically on the same principle without certian catalyst in the film emulsion ..so it is more for "back ground" than processing.. but the basic principle and effect applies (I think) 
     Imperfections in a silver halide crystal are extremely important to forming a latent image. An imperfection results in a charged region of the crystal, termed a trap. An absent halide lattice ion (in the crystal structure, not free to move) creates a positive hole trap, a region of positive charge imbalance, and can keep excited electrons from returning to the halide ion before they can reduce a nearby silver ion. An absent silver lattice ion will attract silver interstitial ions, increasing the concentration of silver ions on the surface, where they can be reduced. I will discuss two common types of imperfections: defects and dislocations.
    Frenkel defects occur when a lattice ion is missing. To maintain electric neutrality, it occupies an interstitial position. Because of their larger size, bromine or chlorine ions can not occupy interstitial spaces, but silver ions can. So, a missing silver ion in the lattice produces an interstitial silver ion.
   A dislocation is like a defect except that instead of just one lattice ion missing, a whole plane of the crystal may be offset. This is due to either an edge dislocation, where the displacement of an edge of a growing crystal causes missing crystal cells, or screw dislocations, where a part of the growing crystal face slips by a whole unit cell. These dislocations can be perpetuated throughout the crystal as it grows.
     It is probably not the "exact" mixture in the "transitions" but technically the same physical reaction would take place, with the "defective" lattice and crystaline formation a "bonding" would seem to ba able to be accomplished, and use of a additive would seem to give it that "floating" bed to work in when in activation.. now the problem would be, and I being no chemist, is that when you have the shift in the silver halide (as Jim talks about) would it align the "same" way each time (say x to y) IF it would than it would make producing the iodine crystal matrix also in the correct orientation to block light that has become polarized(?)when the "photochromic" side shifted into position and the iodine crystal either piggy backed or was forced into the lattice..or even possibly using a "metal" base that could work as a "steering" mechanism and have the frame magnitized, even if it was a slot that could be turned on and off to align the polar sides..(-/+) say like a switchor slide.. when flipped it would drag the idodine crystal into alignment.. it's not like we do not have frames with magnetic qualities already (as in the ones for the magnetic "clips")

     Oh well NOT having a "strong" chemistry background (I should have forced myself to stay awake more in class) I'm probably WAY off base here.. anyone with a stronger understanding of chemistry want to jump and and explain to a dumb lat rat why it is not as "simple" as I think it is sounding?

     BTW thanks Jim for the quick response and informative one as well :) ..Oh well it is fun to tinker I guess, though I'm probably to "dumb" to know that something is impossible to do  :Rolleyes: 


 Jeff "still think Tesla was under appreciated" Trail ;)

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## Darryl Meister

> *Jeff Trail said:* 
> indoors I would NOT care about the elimination of glare..so having a clear or nearly virtually a clear shield would be acceptable ..BUT if taking my question and finding a way to "flood" the shield with a chemical reactive substance (transitional) so when you went outdoors and it was activated than you would get the "darkness" in the shield and would increase the amount of absorption (?)..


Interesting proposition... Sort of a photochromic Polaroid filter. I certainly think it could be possible, perhaps via a mechanism similar to photo-isomerization. While I've never heard of one, that's not to say that someone hasn't already been working on it -- or at least considered the idea.

Best regards,
Darryl

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## Lee Prewitt

Jeff,

You definitely paid more attention in Chem than I but what would be the "trigger" for the process?  Transition uses UV but doesn't polarized light cross all the spectrum?  Your super crystal would need to be activated by planed light in all the spectrum, right?  Very interesting...

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## Jeff Trail

Lee,

  Would depend on the"type" of lens, since we know that the vast majority of cr39 is UV cured, the reason the transition (as in New Generation) the chemical is imbibed while take Rodenstock Colormatics which is ambient activated it is through out the whole lens :-)
   So it would depend on how you wanted to have the activator work (ambient or UV) or how you produced the lens..you could always have an injected (molded shield) and being on the base side of the lens it would not really matter.. but if you did go with an ambient activated chromatic material than you could as well go about it in the ocular surface or base.. via a molded lens..
    You can also "decrease" and "increase" the amount of curing time by manipulating the UV as the curing agent.. one of the reasons older lens turn "yellow" :-)
    Since this would be a fairly expensive lens (I would think) you do not "have" to make use of the UV treatment as a cure agent ..I would think that the UV in say the Nu-polar is an "additive" not a by product to get the degree of blockage that it does get.. and since it would "technically" be behind the shield it wouldn't matter one way or the other :-)
   Oh well it's fun to tinker.. just wish Edmond Scientific sold "transition" kits :-) ..I got a laser from them I still tinker with now and than..

Jeff "I think the best job would be to just sit and "think" this stuff up" Trail ..

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## shanbaum

Unless things have changed since I was in that business (which is possible), the "vast majority" of CR-39 lenses are thermally cured, not UV-cured.

I think Lee's question was, what would trigger whatever sort of chemical action would produce your putative polarmatic effect, which wouldn't necessarily have anything to do with how the lens is cured.  To that, I think the answer is, why couldn't the (putative) polarizing effect be triggered by UV?  Just as (actual) neutral density photochromics are triggered by UV? 

Especially since we're making all this up?

The point being, the wavelengths of the triggering energy needn't have anything to do with the wavelengths (or orientations) of light absorbed by the filter once activated.

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## Lee Prewitt

> *shanbaum said:* 
> The point being, the wavelengths of the triggering energy needn't have anything to do with the wavelengths (or orientations) of light absorbed by the filter once activated.


Is this really true?  Doesn't Transition need to be continuously exposed to UV (It's trigger) to remain dark?  Thus our new lens would need to have the trigger present to remain active otherwise it would revert to its pre-exposed state.

Second question:  Is there another compund besides Iodine that would polarize?  Would it have a photoreactive property?  Perhaps the silver Iodide Jeff mentioned in his photographic paper? I agree with Jeff...lets get paid big bucks to be a think tank.

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## shanbaum

Ideally, you might want the triggering wavelengths to be similar to those filtered.  But UV is inherently more chemically active than visible light and we're talking about outdoors, where both are present in abundance.

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## Jeff Trail

> *shanbaum said:* 
> Unless things have changed since I was in that business (which is possible), the "vast majority" of CR-39 lenses are thermally cured, not UV-cured.


     Well, you are technically correct, as in the "big" picture. But I was going into the additive of uv curing which is added to speed up or slow down the cure rate and how it applies to our little discussion..The CR39 plastic is made by polymerization of the dietilenglycol bis allylcarbonate (ADC). The monomer is an allyl resin containing the following functional group
 [1]: [ CH2 = CH - CH2 - ].
     The monomer is polymerized by adding a few percent of the catalyst diisopropyl peroxydicarbonate (IPP) to the monomer, and then heating. CR39 is a transparent, thermosetting resin but you do have people tinkering with a UV catalyst which I was placing in association with ou thread..is that better? ..boy what a stickler Robert ;)

*BTW you should have to be made to VOTE for me 10 times over for making me pull out my books AND double check my spelling with (ADC)  ..and yes, I did not spell it correctly first go around :-)





> I think Lee's question was, what would trigger whatever sort of chemical action would produce your putative polarmatic effect, which wouldn't necessarily have anything to do with how the lens is cured.  To that, I think the answer is, why couldn't the (putative) polarizing effect be triggered by UV?  Just as (actual) neutral density photochromics are triggered by UV?


    It would have a LOT to do with how the lens was cured, if you had a lens that had a high absorption rate as in "blocking" uv than you would have to go with some type of imbibed process.. where the actual photochromic material would have to be on the outer surface downwards.. while in an ambient activated system this would NOT be a problem..
     The last part is WHAT I was saying to begin with, the polarized (iodine crystals) would be "activated" in a sense.. so now the problem would be two fold.. what would be the activator (UV or ambient) and how would you apply the two seperate  and different crystaline matrix to work in a combined lattice and get the correct effect.. considering the orentation of the polarized crystals would be VERY crucial in the way it filtered polarized light.. so when one (photochromic) activated the other (iodine) would have to be in a certian pattern to get the desired result and effect.. simple enough;) 
      If you did NOT go with an imbibed process and did want it to be UV activated, I am afraid than you would have to revert to the old "lamenated" system of application of the sheet ..which with the newer and more complex adhesives may not be as bad as wel all went through in the older version of "polarized" lens years ago..

     Gee I thought it might be a fun question I didn't know I had to go into the chemistry lab and pull out some stuff a lab rat should stay away from.. we just grind'em remember :Rolleyes: 


Jeff "oh how I hate to be corrected for not going into detail" Trail

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## shanbaum

> *Jeff Trail said:* 
> The CR39 plastic is made by polymerization of the dietilenglycol bis allylcarbonate (ADC).


I'm not familiar with that moniker.   I know it as _allyl diglycol carbonate_ - hence the acronym ADC.

You may have been trying to write oxydiethylenediglycol carbonate, which is longhand for the same thing, I think.

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## Lee Prewitt

> *Jeff Trail said:* 
>       If you did NOT go with an imbibed process and did want it to be UV activated, I am afraid than you would have to revert to the old "lamenated" system of application of the sheet ..which with the newer and more complex adhesives may not be as bad as wel all went through in the older version of "polarized" lens years ago..


Professor Trail:  Would this not be simpler to keep the current lamination technology, which from the dispenser's viewpoint (mine) works very well, and change the iodine matrix within the poly vinyl to a UV activated iodine compound?

Lee "Never made it past Organic Chem" Prewitt :)

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## Jeff Trail

> *Lee Prewitt said:* 
> Professor Trail:  Would this not be simpler to keep the current lamination technology, which from the dispenser's viewpoint (mine) works very well, and change the iodine matrix within the poly vinyl to a UV activated iodine compound?


   Yikes..been called a lot of things..hard headed,stubborn lab rat, even a few SOB's scattered into the mix BUT never that  :Rolleyes: 
   Jim is taking care of some "personal time" and I don't expect him to jump in here (if and or when he might read this I'm hoping for the best and even had my wife light a candle for ya brother) .. but the problem Lee is that all the resin have some UV mixed into the batch and I don't know how the natural ability of the resin to absorb ultra violet is going to effect our little "project".. that is one of the reasons I think that Transitions America went with the imbibing method over the full fusion like Rodenstock..here I'm not to sure about.
    Maybe CEO (where are you?) from Younger might jump in with and tell us how far off base we are :-)

Jeff "I'm happy with just being a lab rat" trail

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## Pete Hanlin

Just have to say this takes me back...  My very FIRST post on OptiBoard (back in 1996) was an inquiry into the feasibility of a clear polarizing lens.  I'm guessing that was about 4,000 posts ago.

Anyway, I believe the key to this imaginary product is going to be a lens that becomes polarized via _electricity_- not UV.  It should be fairly easy to create a lens that darkens when exposed to a small electric charge (its how watches, radio displays, etc. already work).  The challenge would be creating the delivery system and making the lens edgeable.  

Actually, I think I might have seen a patent application for just such a product not too long ago.  It wasn't one of our products, it was just passed along as an "interesting" development.  I don't believe the concept included polarization, but that shouldn't be too difficult to add in- since, as has already been mentioned- LCDs and other electronic displays already exhibit polarization.

Professor Jeff?  Why is that such a scary thought??? :D

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## Jeff Trail

> *Pete Hanlin said:* 
> Anyway, I believe the key to this imaginary product is going to be a lens that becomes polarized via _electricity_- not UV.  It should be fairly easy to create a lens that darkens when exposed to a small electric charge (its how watches, radio displays, etc. already work).  The challenge would be creating the delivery system and making the lens edgeable.


   That is what I was trying to stay AWAY from Pete..it would be easier to use a kinetic energy source than an electrical charge that would have to be made some how.. we have no shortage of UV when out doors but you would have to have something to make the electrical charge.. either UV or a magnetic pole would be far easier and cheaper to produce (as in free in the UV's case) .. and more generic, it would be able to be placed in any frame as any other lens blank :-)




> Actually, I think I might have seen a patent application for just such a product not too long ago.  It wasn't one of our products, it was just passed along as an "interesting" development.  I don't believe the concept included polarization, but that shouldn't be too difficult to add in- since, as has already been mentioned- LCDs and other electronic displays already exhibit polarization.
> 
> Professor Jeff?  Why is that such a scary thought??? :D


   The bulk size and limitations of use would make it hard to adapt to an industry wide choice..while if you had it all encased in just a  generic lens "blank" it would be no different than any other lens to produce :-) Got to think ahead ..all us other Mr. Wizard wanna be's are looking for volume and ease of use and production  :Rolleyes: 

   BTW I find it scary because I would have to go back to College a THIRD time, and degree.. twice is enough for me right now :-) I could always go online and get some "sweat shop" crank'em out degree and become a "Dr." .. but two degree's was enough work for me.. PLUS by not knowing what I am talking about, I am not limited in what I "think" can be done.. :Rolleyes: 
   Wondered when you might jump into this thread.. we did with your "tape" idea :-) .. I did get to do a little theoretical brain flexing, which isn't called for as much in just cranking out uncut blanks..

Jeff "when I die, just toss me in a reclaim tank" Trail

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## Lee Prewitt

> *Pete Hanlin said:* 
> Anyway, I believe the key to this imaginary product is going to be a lens that becomes polarized via _electricity_- not UV.  It should be fairly easy to create a lens that darkens when exposed to a small electric charge (its how watches, radio displays, etc. already work).  The challenge would be creating the delivery system and making the lens edgeable.


I see already that Jeff has jumped on this but wanted to add my penny to the pile.  UV or an electrical charge is still just energy.  Either one will excite the atoms to jump around but which one is readily available or cheap to generate?  Light of course is all around us and need not be generated, don't need to worry if my battery is charged or find some way to engineer a power distribution grid into my product.

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## Pete Hanlin

I see already that Jeff has jumped on this but wanted to add my penny to the pile. UV or an electrical charge is still just energy. Either one will excite the atoms to jump around but which one is readily available or cheap to generate? Light of course is all around us and need not be generated, don't need to worry if my battery is charged or find some way to engineer a power distribution grid into my product.
Well yes, whether you're talking about visible light, x rays, or radio waves, its all electromagnetic energy.  This raises an interesting thought... perhaps we could have lenses which turn into occluders in the presence of wavelengths used for cell phones.  That way, if you were driving and tried to make a cell call...

I think electricity is going to be easier to use because you can control it better than UV (it is hard to store UV).  Why not create a lens/frame package with a solar collector (therefore getting the energy from the sun) and an electrically controlled tint (therefore gaining the ability to have tint in the absence of UV)?

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## Lee Prewitt

> *Pete Hanlin said:* 
> I think electricity is going to be easier to use because you can control it better than UV (it is hard to store UV).  Why not create a lens/frame package with a solar collector (therefore getting the energy from the sun) and an electrically controlled tint (therefore gaining the ability to have tint in the absence of UV)?


Remember that the original intent is to have a lens that will be a photoreactive polarizer.  With a UV activated lens, this lens will adjust its polarization level according to the available light.  Bright days, cloudy days and days in between would all be covered.  Not saying that there aren't any applications but what situations would warrant polarization in the absence of UV?

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## Oha

This was a great thread - Im glad I got to read all the replies.

But it seems that no one could answer the problem of the clear camera polarizing filter.

I remember (way back) in high school, where I took pictures for the paper and yearbook, and some local newspapers too, that there WAS a polarizing lens which was clear, or virtually clear.  And I remember that it worked very well for an assignment I had which involved shooting a picture of something inside a window.

I know it worked well.  But HOW ?????

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## Jeff Trail

Gee, people go back and read some of our ranting and wondering posts? Yikes this might scare some people :) I never did really figure out how if my original posted questions that started this thread had any basic provable theoretical answer..(oh well) I came at it from a few angles but never got any one in a strong chemistry background to jump on the thread to tell me if I was on or way off base.. BUT to possibly explain your question we might have to consider that a polarized filter for a cam is and looks like fresnal, but the difference in image transmission and "end" perception might be the key to your answer, in photography we are dealing with an "instant" image that is captured so loss of transmission due to contrast or density or even clarity can be technically altered by use of focal length, F-stop, film speed, flash etc., etc. (photography was one thing I never really got into) ..while in our visual system we are dealing with constantly moving images multiple focal lengthes and corrected accuity, we are a walking constant three D imaging process using two visual pathways that are combining visual images but even though we may see something in focus (say corrected accuity "BVA") does not always mean we have good vision, take for instance our corrective lens we wear, the lens is correcting a focal problem (hyperopia, myopia etc., etc.) but that same lens is also reducing light transmission which can have a direct effect on our "perception" of what we see.. take for instance 1.60 material, you actually lose 10% light transmission due to the actual material its-self due to internal/external reflection and deviation (which is one of the reasons we should push AR BTW :)) Most people notice when removing thier glasses even though things become blurred it seems or appears "brighter" :) ..
    BTW since someone has brought this thread back to life how about any new idea's on how crazy we were? Any new posters feel like tossing out idea's (if you stay awake through our rambling that is) I still am looking for an "answer"

Jeff"still tinkering, guess it's in my blood" Trail

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## chip anderson

Lee:

Glare under surgical lights,  wanting more light without glare for color recognition (like when I paint prosthetic eyes) to name a couple.

Chip

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## Lee Prewitt

Chip,

Have you tried some of the A polarized lenses?  Or how about taking a camera polarized filter and cutting the glass down?  Would that work?

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## chip anderson

No, Lee I haven't but thanks for the tought.

Chip

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## edKENdance

Apparently the people on the general board think this  is crazy.  I just think it's a really cool example of polarization that I had never thought of before.
I recently saw an ad for light pastel coloured gradient polarised lenses.  How do you have a gradient polarized lens?
Someones' been tinkerin'

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