"FREE-FORM" confusion ???

[skirk1975]

It had been my understanding that "freeform" by definition is a "departure from the ceramic to glass molding process". I took that to mean that the progressive design had to be placed directly on the lens in a digital generator in order for it to be freefrom. Otherwise it is just a digitally surfaced lens (molded PAL with power digitally surfaced).

I have now heard that any lens that has the power digitally surfaced can be called freefrom because it just refers to the complex curve ability of the surfacing. It can be freefrom whether or not the PAL is a mold or put directly on the lens.

What is What here once and for all ???

:angry:

[ThatOneGuy]

It had been my understanding that "freeform" by definition is a "departure from the ceramic to glass molding process". I took that to mean that the progressive design had to be placed directly on the lens in a digital generator in order for it to be freefrom. Otherwise it is just a digitally surfaced lens (molded PAL with power digitally surfaced).

I have now heard that any lens that has the power digitally surfaced can be called freefrom because it just refers to the complex curve ability of the surfacing. It can be freefrom whether or not the PAL is a mold or put directly on the lens.

What is What here once and for all ???

:angry:

yes.

That is why you have to know what you are selling. Companies are playing word trickery all over the place, and using pretty pictures, charts, and graphs to suggest that their products are something they are not. Companies love to use the word "patented" like they use free-form and digital. The problem is, they use the words knowing that you'll associate them in your mind with "better," when in fact the product itself may not be.

What I think you are most confused about, though, is what digital and free-form are. Digital and Free-form are NOT products, and frankly aren't even product features. They are processes. A simplistic way of thinking of them is as follows:

Digital:

1's and 0's. Digital means nothing more than the design came from a computer file. What the company does with that file is where you will see a vast array of product differences.

Free-form:

Simply means the lens was generated with a free-form generator. That's it. Anything can be made on a free-form generator, but not everything takes advantage of the benefits of the process. This is where you must scrutinize your products to really know what you are giving someone.

[Barry Santini]

We're *not* selling Free Form. We're selling digitally-enhanced.

FWIW

Barry

[WFruit]

Darryl and I were having a good discussion on the subject in this thread: http://www.optiboard.com/forums/show...ens-blank-size

I'm going to go ahead and quote his last post, as it's nicely relevant:

It is important to remember that the terms "digital surfacing" and "direct surfacing" and "free-form surfacing" actually refer to the very same process: The fabrication of a non-circularly-symmetrical surface using a free-form surfacing process.

At the end of the day, free-form surfacing is just a manufacturing platform. Contrary to popular belief, there is no inherent benefit of this technology to the wearer, without some form of optical customization. Free-form surfacing can be used, for instance, to produce basic progressive lenses from "points files" that are comparable in performance to traditional, semi-finished progressive lenses. In fact, without sufficient process engineering, it is entirely possible to produce progressive lenses that actually perform worse optically than traditional, semi-finished progressive lenses.

On the other hand, wearers can enjoy significant visual benefits if free-form surfacing technology is combined with real-time optical design software that is capable of optically customizing the lens design for parameters specific to the indvidual wearer, immediately prior to fabrication. This kind of software relies upon complex ray-tracing procedures combined with mathematical modeling and optimization algorithms using data such as the wearer's precription requirements, fitting parameters, frame size, and so on.

Since Essilor prefers the term "digital surfacing," and typically utilizes this technology to produce atoric-like surfaces on the back of semi-finished progressive lens blanks, the term "digital surfacing" has become closely associated with this particular product solution. It is still possible to optically customize a lens design in this manner. The ZEISS Gradal OSD (optimized surface design) and Rodenstock Multigressiv lenses are early examples of this technology. As always, there are both advantages and disadvantages associated with this technology.

Some may argue that placing the progressive optics on the back surface or splitting them between both surfaces affords some optical advantages, but in reality the differences are generaly small due to fact that progressive lenses represent relatively thin optical systems. The greatest optical benefits will be derived from optical customization of the lens design for the specific visual requirements of the wearer.

"Digitally molded," which is another common misnomer exploited by certain lens suppliers, refers to a mold-making process that relies on free-form surfacing or milling the mold, instead of "slumping" the mold over a ceramic former that has been milled using free-form technology. "Digitally surfacing" molds directly has been a very common method of making molds for decades, particularly for the metal molds used with polycarbonate lenses, although certain lens manufacturers have begun capitalizing on the recent interest in free-form surfacing technology by marketing their semi-finished lenses as "digitally molded." There are actually advantages and disadvantages to either approach in terms of manufacturing consistency, ability to replicate certain lens design features, and so on.

Best regards,
Darryl

Continuing the discusison, when I think of "Free Form" I think of the ENTIRE process, including both physical processing of the lens, and the software anaylsis/compensation of input Rx and additional POW data.

One can certainly say that digital generating and free form surfacing are the same thing. It's the software determining what is being surfaced that makes the difference.

In response to the OP, it is my opinion that a "Free Form" lens is one where the software custom creates the entire lens design which is then Digitally surfaced onto the lens. Anything else, even when software optimization is used, is merely "digitally surfaced."

I think Darryl and I are arguing the same thing (agreeing with each other), just from two different view points (and he's more elloquent than I am).

[ThatOneGuy]

Darryl and I were having a good discussion on the subject in this thread: http://www.optiboard.com/forums/show...ens-blank-size

I'm going to go ahead and quote his last post, as it's nicely relevant:



Continuing the discusison, when I think of "Free Form" I think of the ENTIRE process, including both physical processing of the lens, and the software anaylsis/compensation of input Rx and additional POW data.

One can certainly say that digital generating and free form surfacing are the same thing. It's the software determining what is being surfaced that makes the difference.

In response to the OP, it is my opinion that a "Free Form" lens is one where the software custom creates the entire lens design which is then Digitally surfaced onto the lens. Anything else, even when software optimization is used, is merely "digitally surfaced."

I think Darryl and I are arguing the same thing (agreeing with each other), just from two different view points (and he's more elloquent than I am).

Your analysis, I believe, is why the industry is having a field day with us. Thinking of Free Form as the "ENTIRE process" is why you will be had by a lens manufacturer. This analysis you've provided would suggest that a physio 360 is equivalent to a Hoya ID is equivalent to a Zeiss Individual. You would be wrong.

Think of a skate boarder and a person who grinds their teeth. If they do not know anything about one another and they each state how grinding is fascinating, they would never realize that they are talking about different things.

That is what manufacturers are doing. Shamir comes in and says check out our new free form design that is customized with a variable fit height. Then, Zeiss says check out my free form design that is customized with a variable fit height. Then Hoya jumps in the mix and says hey look at me too! They are all making the same statement, and they are all speaking the truth, but based on those statements alone, we can't understand that they are VERY different products, and they are different because of what their software is doing with what information is provided.

[WFruit]

Your analysis, I believe, is why the industry is having a field day with us. Thinking of Free Form as the "ENTIRE process" is why you will be had by a lens manufacturer. This analysis you've provided would suggest that a physio 360 is equivalent to a Hoya ID is equivalent to a Zeiss Individual. You would be wrong. No, because the entire process is what is different for the three lenses you mentioned. For the Physio 360, the process is to pull a Physio blank, enter the Rx, and digitally surface a conventional molded blank (None of the 360 or Enhanced lenses are Free Form). For the Hoya and Zeiss lenses, the process modifies both the front and back surface of the lens to customize that lens blank to that specific Rx with specific POW meansurements for that patient based on the input Rx and POW data. For Shamir and Seiko lenses, the entire progressive design is put onto the back surface with no front surface modifications, with the exact design and powers being modified by Rx and POW information (well, for some of them. Not all of Seiko's and Shamir's designs use POW data). The software for all of them is the first big difference, the second is the manufacturing process of what comes out of the software. Sure, the exact piece of equipment making the lens may be the same. For example, the same generator can run Seiko, Shamir, or any number of other full back surface lens designs. The software here is the key.

That is what manufacturers are doing. Shamir comes in and says check out our new free form design that is customized with a variable fit height. Then, Zeiss says check out my free form design that is customized with a variable fit height. Then Hoya jumps in the mix and says hey look at me too! They are all making the same statement, and they are all speaking the truth, but based on those statements alone, we can't understand that they are VERY different products, and they are different because of what their software is doing with what information is provided. Which is why my first questions about any new lens design are "How is it made? What makes this design different/better than any other design?" And actually, I've found those three to be similar (though certainly NOT the same). The difference is more in HOW they are made (software and physical processing) than in what they do.

+1 for the excellent grinding analogy, I'm going to have to remember that one.

[HarryChiling]

You should be asking what the design benefits of the PAL are?

Here are some of the benefits that free-form processing can and should provide:
1 - better aberration control.
2 - customized design.
3 - expanded material availability.

Each category can be expanded further but I think these three benefits are key areas that should be addressed with free form processing of PAL's.

[skirk1975]

So, can a lens with a molded PAL front (whether if be conventional or digitally designed) ever be considered Free-Form ?


I want to also verify and confirm that the Physio Enhanced is, in fact, NOT freefrom.

[WFruit]

So, can a lens with a molded PAL front (whether if be conventional or digitally designed) ever be considered Free-Form ? NO. By definition (mine at least) a Free Form lens is completely customized for the patient. Starting with a molded front blank automatically limits a person to a set of fixed limitations. Are there limits to Free Form designs? Yes of course. But they are customized and minimized based on Rx and POW data.

I want to also verify and confirm that the Physio Enhanced is, in fact, NOT freefrom. It is NOT. No matter what Essilor says. For the same reason as the answer to your above question. It's a standard Physio blank with the Rx data run through their software (I think it's the second version of their W.A.V.E. software) and then Digitally generated. Is it better than a regular Physio? Yes. Is it as good as, say a Shamir or Zeiss Free Form? Oh, zark no.

Continuing with the first question, it could be argued that Free Form designs aren't really "designs" in the traditional sense, but rather levels and ranges of customization of a progressive. For example, in the Shamir line, you have the Element, Spectrum, and Autograph II. Each one allows more customizations of the Rx based on POW and frame information (they are all still all back surface design progessives).

[HarryChiling]

So, can a lens with a molded PAL front (whether if be conventional or digitally designed) ever be considered Free-Form ?


I want to also verify and confirm that the Physio Enhanced is, in fact, NOT freefrom.

They can free form process an atoric surface onto the back and deliver better aberration control, but the lens is limited in it's customizations and material availability. Also consider that if the lens design is molded onto the front then a set of default parameters were choosen to design that particular progressive surface and if the patients actual parameters deviate from the default then the lens design looses it's intended effects.

Any PAL design can be enhanced ont he back surface and I would like to see that be a feature available in the near future. Many labs provide a SV free form option so if they were to run that program on a PAL blank then the lens could be enhanced.

[RT]

HOYA ID Lifestyle has a molded front, but the front only contains the vertical elements of the progression. As such, the back surface is complex, varies by add power, has a customizable inset, and can be altered based on fitting parameters such as wrap angle and pantoscopic tilt. It is "Freeform" in every sense of the word...but has a molded front.

[Darryl Meister]

This analysis you've provided would suggest that a physio 360 is equivalent to a Hoya ID is equivalent to a Zeiss Individual. You would be wrong.

Think of a skate boarder and a person who grinds their teeth. If they do not know anything about one another and they each state how grinding is fascinating, they would never realize that they are talking about different things

Just keep in mind that your analogy is comparing two entirely different forms of grinding in two completely different contexts. "Digital surfacing" and "free-form" surfacing, on the other hand, at least when anything other than a conventional toric surface is involved, both represent the exact same process. A lens manufacturer that produces back-side progressive lenses could use the term "digitally surfaced," just as a lens manufacturer that surfaces an atoric back surface onto a semi-finished progressive blank could use the term "free-form." Either could even use the phrase "digitally surfacing a free-form lens design."

The association between certain product types and specific uses of either "digital surfacing" or "free-form surfacing" is completely artificial. Although it has become convenient to associate certain terms with certain product types in order to differentiate more easily the lens manufacturer's specific approach to lens production or product branding. Again, "digital surfacing" has become associated with Essilor's approach, whereas "free-form surfacing" is more often associated with back-side progressive lenses. But the exact same machines and surfacing processes are used in either case, although the final configuration of the finished product may vary.

But none of this speaks to the additional visual benefits of the final lens to the wearer, if any.

The actual wearer does not care how the lenses were made, either way. It makes no difference to him or her, whether the lenses were molded, surfaced, or both. On the other hand, the customization enhancements made to the lens design will matter, since these enhancements can improve optical performance and vision quality. The production quality of the product will matter, since a poorly manufactured lens can degrade vision quality. The global performance or geometry of the basic lens design will matter, since the basic lens design determines the maximum possible vision quality.

There are certain optical differences that result from the configuration of the lens surfaces and the distribution of the optics between the front and back surfaces. And, to the extent that differences in skew distortion and the distance of the viewing zones from the eye actually influence vision, the configuration of the free-form lens may be important to the wearer. These differences are often small though. Further, there are also various manufacturing implications involved when free-form surfacing lens designs of increasing complexity or when combining factory-molded and digitally-surfaced optics.

Also consider that if the lens design is molded onto the front then a set of default parameters were choosen to design that particular progressive surface and if the patients actual parameters deviate from the default then the lens design looses it's intended effects

In Essilor's case with their "Fit" lenses, they are claiming to apply optical optimization to the back based upon the position of wear. So, although the initial semi-finished progressive lens design would be optimized for a default position of wear, the final lens could be optimized for a specific position of wear by fine-tuning the optics of the back accordingly. The back surface, however, is more complex than a symmetrical atoric surface in this case.

Then, Zeiss says check out my free form design that is customized with a variable fit height

Actually, the order was SOLA then ZEISS then Shamir. ;)

You should be asking what the design benefits of the PAL are? Here are some of the benefits that free-form processing can and should provide:
1 - better aberration control.
2 - customized design.
3 - expanded material availability

Exactly.

Best regards,
Darryl

[ThatOneGuy]

Actually, the order was SOLA then ZEISS then Shamir. ;)

My post was intended to offer insight in to the word games of manufacturers, not to be a historically/factually accurate representation of the specifics. When I was growing up and asked my brother for help with my homework, he would never give me the answers. He would only offer to show me how to understand the answers.

[Darryl Meister]

My post was intended to offer insight in to the word games of manufacturers

No worries. But as an employee one of those manufacturers, I can assure you that we have no interest in words games. In fact, this is why my post sought to clarify the fact that the only distinctions of significant visual consequence between these technologies are only based upon the lens design and how it has been enhanced for the wearer, not necessarily upon the specific manufacturing method or what it is called. This is also why I am very sensitive to the confusion created by those manufacturers who do rely on word games to exploit the misconceptions in the marketplace regarding these technologies.

Best regards,
Darryl

[Judy Canty]

No worries. But as an employee one of those manufacturers, I can assure you that we have no interest in words games. In fact, this is why my post sought to clarify the fact that the only distinctions of significant visual consequence between these technologies are only based upon the lens design and how it has been enhanced for the wearer, not necessarily upon the specific manufacturing method or what it is called. This is also why I am very sensitive to the confusion created by those manufacturers who do rely on word games to exploit the misconceptions in the marketplace regarding these technologies.

Best regards,
Darryl

+1

[eyemanflying]

No worries. But as an employee one of those manufacturers, I can assure you that we have no interest in words games. In fact, this is why my post sought to clarify the fact that the only distinctions of significant visual consequence between these technologies are only based upon the lens design and how it has been enhanced for the wearer, not necessarily upon the specific manufacturing method or what it is called. This is also why I am very sensitive to the confusion created by those manufacturers who do rely on word games to exploit the misconceptions in the marketplace regarding these technologies.

Best regards,
Darryl

Great accurate description but...

All companies play the name game including the one that signs your paycheck (just different degrees/versions of confusion and self made claims). 3D PALS anyone? Or morphing technology? Hmmm, perhaps the Z marketing guru was a Mork and Mindy fan? Or was it Tim Conway? Good thing we don't manufacture and market in 2D technology - that would really suck for pilots and people that drive.

The one that takes the cake is Nikon's '3D Abberation Filter'? I laugh every time I hear that one becuase it's so ridiculous. I could be wrong but I swear since I have fortunately had binocular natural vision since birth I was always seeing in 3 dimensions??? Oh nooo, I'm so confused! I can't imagine how the consumers are feeling.

I can't wait until the 4D version becomes available - heck, I may have to wear a cape since it will give my eyes super powers.

[racethe1320]

So, can a lens with a molded PAL front (whether if be conventional or digitally designed) ever be considered Free-Form ? I want to also verify and confirm that the Physio Enhanced is, in fact, NOT freefrom.

Free form/digital are just marketing terms from the various manufacturers. The process is essentially the same. I use the term digital but that's just me. The process allows for a lot more customization and accuracy. 1/100th of a diopter vs 1/10th. Some lenses are cut on the back, some on front and back.

[Darryl Meister]

All companies play the name game including the one that signs your paycheck...

You're confusing "word games" with normal product branding. GT2 3D is just a product brand name. It represents no more of a word game than "Kleenex" tissue or "NyQuil" nighttime cold medicine or "Armor All" surface protectant. I think this point is obvious to most consumers, who have been buying products with brand names their entire lives

As is often the case with product branding, the name is meant to convey an association with the primary benefit or positioning of the product. Product branding is also important in order to differentiate similar products from each other, like "Pepsi-Cola" kola-flavored soda versus "Coca-Cola" kola-flavored soda.

As the described in the white paper, which also details the optical principles involved, GT2 3D is a "new progressive lens that has been designed with particular emphasis on binocular vision in order to deliver a more natural viewing experience." Yes, I guess the Marketing people could've skipped the clever brand name and relied on a more technically accurate description, but GT2 Progressive Lens Design with Minimized Binocular Power Gradients for Improved Binocular Fusion and Stereopsis wouldn't have tested well in focus group research.

SOLA's morphing technology is indeed just that: the same type of computer "moprhing" technology that is utilized for certain movie special effects. For instance, using this technology the zones of a progressive lens design can be expanded, contracted, or rotated over a continuous range between two completely different lens designs. The specific details can be found in US Patent 7,344,245. You will notice that the term "morphing" is also utilized as in the patent as a scientific term.

In any case, I prefer speaking in generalities and discussing general optical principles, not the specifics of any one particular product or brand. You will notice in my posts above, for instance, that I never actually refer to any products by name, including any products by Carl Zeiss Vision, with the exception of Essilor's "Fit" lenses in response to a previous reference to this specific product by another OptiBoarder.

Best regards,
Darryl

[Darryl Meister]

The process allows for a lot more customization and accuracy. 1/100th of a diopter vs 1/10th.

Just keep in mind the following two points:

1. The "accuracy" of a free-form surfacing process due to the use of soft lap tools means that free-form surfacing can produce a surface to the same dioptric value as your prescription. Traditional surfacing can produce a surface to within +/-0.05 D of your prescription using modern hard lap tooling. But, since even under ideal circumstances the depth of focus of the wearer is at least +/-0.12 D, an improvement of +/-0.05 D is less than half of what the eye would ever notice, anyway. Most patients would be unwilling to pay an extra premium for a difference in performance that they could likely not even detect.

2. Optical "customization" of the lens design based upon parameters specific to the visual requirements of the wearer, on the other hand, can result in significant differences in optical performance, particularly in lenses with cylinder power, higher sphere powers, unusual positions of wear, unusual frame sizes, etcetera. But the extent of optical customization varies significantly among lens manufacturers. Optical customization is in no way inherent to free-form surfacing, this technology simply makes some level of customization possible. In fact, some free-form lenses are comparable in performance to traditional, semi-finished progressive lenses.

Again, not all "free-form" or "digitally surfaced" lenses offer the same level of visual improvement for the wearer. At the end of the day, "free-form" is not a feature of the lens, it is a manufacturing method that allows certain manufacturers to impart certain features, should they actually have the desire and, more importantly, engineering wherewithal to do so.

Best regards,
Darryl

[eyemanflying]

To really capture the essence of technology acuracy, all we need now is for every OD or OPT to purchase a lensometer capable of measuring in units of 1/100th of a dioptre.

[Darryl Meister]

To really capture the essence of technology acuracy, all we need now is for every OD or OPT to purchase a lensometer capable of measuring in units of 1/100th of a dioptre

Given that it only translates to a potential improvement of +/-0.05 D, I don't feel that the additional "accuracy" (in reality, we're discussing "prescision") of free-form surfacing is really all that meaningful. Of course, since most of these lenses arrive with a compensated prescription written out to 0.01 D, anyway, a focimeter with a precision setting of 0.01 D would be useful either way. In the US, automatic focimeters with this capability are relatively common though.

Best regards,
Darryl