Time for some clarity on progressive technology...

[Chris Ryser]

I can not from memory recall what European Countries can be handled with one application but I believe that this is controlled from Spain.

European patents are filed in Munich Germany. Once they have passed the procedure.......about 2 years.................they are granted. Following that you can file for patent protection in each individual country of the European comminuty you wish. That involves an initial fee for each country and a yearly upkeep fee.

Worldwide patents do not exist...........patents have to be filed in each individual country plus yearly upkeep fees, where you want to have protection.

[Samuel Jong]

Varilux Physio uses a semi-finished progressive lens surface. While the molds used to manufacture Physio may have been produced using "free-form" technology, this is true for virtualy all semi-finished progressive lenses.

Is Gradal Individual also using "free-form technology"? Thanks.

[Darryl Meister]

Gradal Individual is a true "free-form" lens in the sense that each lens is custom-designed and manufactured to wearer specifications using a free-form generator.

[Samuel Jong]

Gradal Individual is a true "free-form" lens in the sense that each lens is custom-designed and manufactured to wearer specifications using a free-form generator.

Thanks a lot Darryl.

[lensgeek]

Shamir's Creation along with Varilux' Physio are semi-finished progressive lenses. Both have eliminated the "master mold" or "mechanical mold" when applying the mathematical design directly to the production (glass) molds...bypassing the ceramic mold process will produce a progressive lens with higher resolution due to some degradation which can occur while continually "copying" a design from a ceramic master to a glass production mold....

However, extending a base curve selection gives a wide perscription range a chance to be matched to a more appropriate base curve, resulting in both optical accuracy and a flatter profile.....

Bottom-line...many traditional semi-finished progressive lenses have proven themselves to be "good" products...digitally applying the design via "freeform optics" will produce a "better" product...without a doubt, full customization through freeform technology are the "best"

[Darryl Meister]

Shamir's Creation along with Varilux' Physio are semi-finished progressive lenses. Both have eliminated the "master mold" or "mechanical mold" when applying the mathematical design directly to the production (glass) molds...bypassing the ceramic mold process will produce a progressive lens with higher resolution due to some degradation which can occur while continually "copying" a design from a ceramic master to a glass production mold

Good points, but keep in mind that:

1) Metal molds for many polycarbonate progressive lenses have been cut directly for decades, yet no one ever claimed that this provided a meaningful benefit to the wearer.

2) Zeiss has already been grinding glass molds for plastics directly using free-form generators for years. So neither Creation nor Physio were the first to do this, even in hard resin.

3) You still sacrifice some degree of design resolution using a free-form process since the mold must be polished, which -- depending upon the polishing method and starting smoothness of the surface -- can still result in departures from the desired lens form. Though, admittedly, improvements in the surface quality off free-form generators has improved over the years. Further, the loss in resolution using a former is probably quite small compared to the more "global design" considerations, such as the configuration of the viewing zones, corridor, and design of periphery.

4) To say that the design is "continually copied" from a ceramic former insinuates that copies are being made of copies, which is not the case. Each new mold is produced from the original master, so there is no propogation of error or anything like that.

5) Even if you use a free-form generator to produce glass molds, you are still casting the lenses for semi-finished lens blanks. Consequently, you are still going to see changes in the lens design as a result of shrinkage and other manufacturing variations. This isn't necessarily the case when directly surfacing the design to the lens blank (assuming your process is carefully controlled). Also, following your line of thought, one could then argue that a "free-form" progressive lens surface produced entirely using a free-form process should be better than a comparable "free-form" progressive lens using a semi-finished progressive front with an optimized free-form back surface.

6) I still feel that this language is exploiting to some degree a misconception regarding the term free-form. "Free-form technology" has come to be associated with customized progressive lenses that have been designed and optically optimized for the individual wearer's prescription and fitting parameters. However, this is not always the case for so-called "free-form" lenses (for example, simple "point files," even surfaced directly using a free-form generator, are not customized). And it is certainly never the case with semi-finished lenses.

That said, now that everyone else is using such language, we'll almost certainly be forced to follow suit. Just like we all had to after one particular lens manufacturer started describing their 1.66 high-index lenses as "1.67" lenses in the US a few years back. ;)

However, extending a base curve selection gives a wide perscription range a chance to be matched to a more appropriate base curve, resulting in both optical accuracy and a flatter profile.....

I agree. But this has nothing to do with the manufacturing process, nor the quality or implementation of the lens design. It really boils down to a sales and marketing choice: Do you want a more manageable inventory or more precise optics? Nowadays, most manufacturers try to strike a compromise between the two.

[Michael Walach]

Free Form Surfacing Does Not Reffer To A "free Tool", Which I Do Not Undestand What Exactly You Would Be Reffering To, But Rather To Surfacing Process Where The Surface Of The Lens Can Not Be Defined By One Single Algorithm, But Rather Extrapolation Of Various Algorithms Tangenialy Compiled Into One Surface. Quite Common Process The In Machining Industry, Accurately Definable, And Effective. The Way To Go In The Ophthalmic Lens Processing Profession!

Michael Walach
Quest Optical Specialty Lab

[lensgeek]

Darryl...Thanks for responding to my recent post. In all due respect to your optical expertise, please allow me to clarify any misconceptions or misunderstandings.
It would certainly be difficult to compare a semi-finished design processed from a polycarbonate vs hard resin monomer...I should have specified hard resin/higher index monomers when comparing degradation due to continual casting....
I did not claim that Essilor or Shamir were the first to digitally apply a progressive design to glass production molds, although I do not agree that this process is the "norm"..these two manufacturers were compared in a thread to which I responded...
When referring to the original "master mold" I did not state that copies were made from copies...simply, the original master mold will degradate over time as well as the glass molds produced from it after repeated "casting"...I agree that a "freeform" generated glass mold will undoubedly lose resolution over time....
I will still stand firm on my belief that a "freeform surface" produced entirely using a "freeform process" is better than a comparable "freeform progressive" lens using a semi-finished progressive front with an optimized "freeform" back-surface for 2 reasons...
1.) Full customization - allowing frame and personal measurements into the design equasion.
2.) No margin for "human error" in re-aligning/blocking a semi-finished digital design prior to surfacing a "freeform back surface....
Thanks for your comments....you keep me on my toes!! Respectfully, Lensgeek

[Darryl Meister]

Lensgeek, I want to preface my response by saying that I certainly appreciate the fact that you understand these issues well enough to pose some interesting points for discussion. The forum certainly benefits from this kind of information and debate.

I should have specified hard resin/higher index monomers when comparing degradation due to continual casting....When referring to the original "master mold" I did not state that copies were made from copies...simply, the original master mold will degradate over time as well as the glass molds produced from it after repeated "casting"...

Then perhaps I misunderstood the point you meant to convey when you stated that "...bypassing the ceramic mold process will produce a progressive lens with higher resolution due to some degradation which can occur while continually 'copying' a design from a ceramic master to a glass production mold...." After all, any changes that occur as a result of continued casting will affect molds cut directly from a free-form generator just as quickly as molds cut from a ceramic former. Further, both of these lenses are still cast traditionally, so neither represents an actual free-form surfaced lens blank (even in the free-form" version, Varilux Physio 360 still uses a semi-finished progressive lens surface -- though, in my opinon, this approach is not without its advantages).

I did not claim that Essilor or Shamir were the first to digitally apply a progressive design to glass production molds, although I do not agree that this process is the "norm"..these two manufacturers were compared in a thread to which I responded...

Now, I am certainly not trying to pick on Essilor or anyone else. I happen to think very highly of Essilor, their products, and their people, and I generally don't like to involve myself in product-specific conversations like this. My point was only that several manufacturers are now attempting to differentiate their products using this terminology, though it actually describes a technology that has been in place for many years. (Free-form cutting, for instance, is the "norm" for the second most popular lens material in use today, polycarbonate, and is used at some stage for every progressive lens sold.)

You used these two particular products as examples, and suggested that they achieve better design "resolution" than other semi-finished progressive lenses. While I would be quick to point out as a Zeiss employee that Zeiss has been directly cutting glass molds for progressive lenses for many years now and that the progressive surface of our free-form lenses are directly surfaced if I simply wanted to "play those cards," I think it is considerably more important to talk about what free-form can accomplish for the wearer in terms of customization. I don't even agree that the free-form manufacturing process is inherently far superior to traditional casting, but -- even if it were -- the differences to the wearer would be negligible compared to a free-form lens that starts with a high quality progressive lens design and then improves its performance using a good optimization program.

[lensgeek]

O.K, Darryl....can we agree that...manufacturers are moving in a forward direction when directly applying their highest quality progressive design (to a production mold) via freeform equipment and/or optimizing full customization through a true freeform generated lens beginning from scratch (SV semi-finished blank) resulting in a better final product, again, derived from its highest quality design...I would be the first to agree that the quality of design will dictate ease in adaptation no matter which process is chosen...a poor design will just be a better poor design given advanced production methods....
For some reason, your company (and others) chose to move forward in developing advanced designs combined with advanced production methods. I would like to believe it is more than just the "marketing hype" shared by many viewers posting in these progressive discussions.....

[Darryl Meister]

Those are all very good points to make. I'll add that even free-form manufacturing has improved quite a bit over the last few years, as newer machines are able to achieve smoother surfaces that require less polishing (an operation that can potentially alter and distort the surface).

[AustinEyewear]

Wow - Great thread from the way-back machine. Reading thru this thread now has me wondering if there is (still) a patent on back-side free-form progressives? Its seems there are many manufactures using this technique now, so it would seem they have all come to terms or the patents have expired or something? Anyone have clarity on this?

[Judy Canty]

For lack of a better word, the designs are "leased" on a per use ("click fee") basis from the lens manufacturers/designers.

[AustinEyewear]

For lack of a better word, the designs are "leased" on a per use ("click fee") basis from the lens manufacturers/designers.

Are they paying royalties to someone? Who is that entity?

I thought about this a little more, and realized my question may not have been specific enough. What I am asking is not about the freeform software itself, I'm asking about the ability to utilize a backside progressive surface. From reading thru some of these posts, it appears that this what would seem simple enough issue, is patented, forcing others to ether place the progressive surface on the front, or pay royalties for the privledge of placing it on the back (even though they develped their own free form software that will creat the point files to generate the surface using a CNC machine). Is this the situation? Does my question make sense?

[Judy Canty]

There are a very small handful of lens designers in this industry, and it's not all that easy to develop, test and then market new lens designs. So this handful works for whomever signs their checks. The designs are available, as I said via a "click fee" or a "royalty". Anyone with the capabilities can put a design on any surface, but they've got to get the design from someone. Some manufacturers who seem to introduce new designs at an alarmimg and often confusing rate may actually be "tweaking" an existing design and re-introducing it. It's that "new and improved" designator we see so often in the grocery aisles. If your rep can't explain the differences in understandable terms, not marketing jargon, then perhaps it's not really new or improved.

[AustinEyewear]

There are a very small handful of lens designers in this industry, and it's not all that easy to develop, test and then market new lens designs. So this handful works for whomever signs their checks. The designs are available, as I said via a "click fee" or a "royalty". Anyone with the capabilities can put a design on any surface, but they've got to get the design from someone. Some manufacturers who seem to introduce new designs at an alarmimg and often confusing rate may actually be "tweaking" an existing design and re-introducing it. It's that "new and improved" designator we see so often in the grocery aisles. If your rep can't explain the differences in understandable terms, not marketing jargon, then perhaps it's not really new or improved.

Sorry, not sure if I was clear. I was referring to the comments below. I'm wondering if the big boys who do have the ability and financial resources to design the software have to pay royalties to put their designs on the backside because someone holds a patent to put the PAL surface on backside? (yes, I do understand the designs evolve and are licensed)

The first US Patent issued covering this issue is US Patent 6,019,470.

This Patent issue is real and I would not recommend selling lenses produced with a backside PAL unless these are manufactured outside of the US.

This Patent is not licensed to Shamir for the Autograph as I understand.

I would like to thank Laurie for the confirmation of my belief. I do not understand why Shamir is currently attempting to have their partner labs produce these backside PAL lenses without the assignment of the rights to do so. It is my understanding that Shamir does not have such rights.
This is a new area for optical lens production and is quite different from other PAL designs in the ability to produce very customized lenses.

Laurie;


In the above you state that Shamir may very well hold the patent. Which they certainly do not hold the original patent for backside progressive maintaining a spherical front surface.



I await your findings. In another thread someone else reports this patent issue has been resolved. I have not been able to confirm this resolution. I would think if Shamir does have a clearly defined resolution that the information would be available.

It is my understanding that there are overlapping patents issued covering the technique of spherical front/PAL back. One is owned by Seiko-Epson, the other is owned by Carl Zeiss Vision. Seiko-Epson has given lens companies such as Shamir the right to use this technique, for a small fee, <wholesale pricing removed>. Unfortunately, CZV has not. This issue remains unresolved and is currently the biggest obstacle to this technology coming to market.