What Lens are truly Freeform?

[Judy Canty]

Indeed they are, but you can digitally produce any lens design. Digital processing will not make a bad or an old design better. Free form lenses have both the design and the rx digitally produced on the back side of the lens. So in answer to your question, the Varilux DRx lenses are free form, as are products from Zeiss, Seiko, Shamir and Hoya. The point is that you need to understand the technology, not simply depend on the marketing.

[AustinEyewear]

Indeed they are, but you can digitally produce any lens design. Digital processing will not make a bad or an old design better. Free form lenses have both the design and the rx digitally produced on the back side of the lens. So in answer to your question, the Varilux DRx lenses are free form, as are products from Zeiss, Seiko, Shamir and Hoya. The point is that you need to understand the technology, not simply depend on the marketing.

Thanks CuriousCat. I have a pretty good handle on what freeform technology is. I won't claim I have a great understanding of optics/physics, but I TOTALLY get what freeform is about. When I look at the Essilor brochure, I'm confused on if they are actually producing a freeform lense. Many people say no. Essilor does not come out and make it a distinct point either, which further confuses me, why wouldn't they just say it clearly? If designed correctly, freeform WILL be a superior technology. The mathmatics prove it. If the machines are calibrated and all variables are kept under control, it is my opinion freeform is superior. But I'm not here to discuss this thoeology. I'm trying to figure out if Essilor ACTUALLY produces a TRUE freeform lense. Whether it be a good or bad design is irrelevant to me.

From the literature and links I provided, it would seem that they produce several free form lenses, some with a backside CNC surface, and using their latest technology called DUALOPTIX, it appears they are using a CNC machine to surface both sides of the lense. And of course, I am assuming they are using sofisticated software to produce the topograpical maps of the lens surface a.ka. freeform.

What do you think? Is it the DrX only, the literature seems to say otherwise? What is this DUALOPTIX?

[Judy Canty]

You know I wish I could tell you, but I can't. The waters in Dallas are pretty muddy. Perhaps there's a Varilux rep out there who would like to help me out?

[MakeOptics]

I use the seiko surmount for my plus patients which is super flat and have never had issues with the lens. I would counter the smaller sweet spot with a wider apparent field of view by moving the constrained surface to the back and even making it convex as is the case with the surmount.

Also eccentricity can be applied to the front and back surfaces of lenses to counter choices in curves. In the case of plus powers we really can't discus higher plus powers and best form without a discussion of aspherics. A high plus lens can have asphericity applied to one or both surfaces to imporve optics. When applied to the front eccentricity flattens the curve, to the back steepens the curve, the overall effect for all intensive purposes is the same.

[TLG]

I'm trying to figure out if Essilor ACTUALLY produces a TRUE freeform lense. Whether it be a good or bad design is irrelevant to me.
What do you think? Is it the DrX only, the literature seems to say otherwise? What is this DUALOPTIX?

Well, the Ipseo is also full freeform but nobody uses that so that leaves the DRx. ALL of the other Physio flavors have a molded front PAL design and are 'digitally surfaced' on the backside; yes, the front side mold IS cast from a digitally surfaced glass mold and yes, they ARE cut on CNC generators... but few people (outside of Essilor) would agree that that make it 'freeform' - it is not. As far as "dual add" goes, consider that half of the 'duo' is molded onto the front, with the other half - and the rest of the PAL design and Rx - digitally surfaced on the back. I'll let you decide if that is a 'true' freeform.
Essilor is far from alone in being vague about their product technology.

[AustinEyewear]

Well, the Ipseo is also full freeform but nobody uses that so that leaves the DRx. ALL of the other Physio flavors have a molded front PAL design and are 'digitally surfaced' on the backside; yes, the front side mold IS cast from a digitally surfaced glass mold and yes, they ARE cut on CNC generators... but few people (outside of Essilor) would agree that that make it 'freeform' - it is not. As far as "dual add" goes, consider that half of the 'duo' is molded onto the front, with the other half - and the rest of the PAL design and Rx - digitally surfaced on the back. I'll let you decide if that is a 'true' freeform.
Essilor is far from alone in being vague about their product technology.

Thanks for the follow up Tony. I'm furiously studying the subject right now. It appears that

Physio Enhanced FIT, Physio Enhanced Eyecode, and Ipseo Eyecode all take into account monocular PD, Fitting Height, Frame Wrap, Panto, VD and some the (special Eyecode/Head Cape/Posture) which would may place them in the category of a freeform.

The DrX only accounts for PD, Fitting Height, but PAL is cut on backside. For what its worth, I would not consider this in the category of a freeform. To me, its more akin to a traditional lens being digitally surfaced on the backside, part way there, but no cigar. No ability to move the optimal reading zone around as one would normally do with a free form lense.


The others mentioned, all appear to be true freeforms, but then they have to throw a wrench into the equation by having this so called DUALOPTIX. As you mention, its hard to know what this would do. I perceive it as a "set" PAL on the frontside, with a "freeform" PAL on the back and it somehow compensates the front design. My gut feel concerning the molded PAL on the front, is that it would ruin the whole reason for going freeform in the first place, but what do I know about this subject, next to nothing, at least compared to the gurus :) To me, a big part of using a PAL freeform design is to provide the ability to adjust the corridor length and move the reading zone to the most optimal position in the frame, and it feels like a molded PAL on the front side would hamper the ability to do this?

[dash1]

I would counter that there is no one BEST lens. Different lifestyles have different needs, so the Best Lens is the lens that compliments a patients lifestyle the most. In general Wider Fields of view are good, but it depends where that wideness falls. Although the Auto II is immensely better than the Comfort, the reading can actually be narrower in the Auto II. If my patient reads a lot, she would be disappointed with her new lenses. There are Free-form lenses with wider reading than the Comfort though, but you get my drift.

It should be noted too, that those lenses requiring advanced measurements such as Panto, Wrap and Face Form will only benefit about 10% of our patient based on RX. I see myself better in the Spectrum than the Auto II in my low RX.

You say there are freeform lenses with wider channels than the comfort? which ones? I've tried moving a couple people from the comfort to the Auto II, unique, etc... and most I've had to switch back? One pt brought in a display visually showing me what he was seeing with both ( he was a wierdo, oops i mean an engineer..) Also, what are some of you using if a pt wants or needs a really wide intermediate but still have a low seg ht, other than restyling to a larger one? I feel most people would benefit from a wider intermediate than reading due to all the electronic gadgets we use.

[sharpstick777]

If you are interested in better computer area than the Auto II, the widest I have seen is the Seiko Surmount, the second widest the Definity, the third the Hoya ID. The last two are Plus shaped in the effective area so the distance narrows significantly. In both the Definity and the Hoya ID I only turn my head a hair in the distance and it gets blurry. With the Surmount I get an effective distance zone that is about 5 or 6 times wider than the Plus shaped lenses mentioned, the Surmount is more Barrell shaped for the effective areas. Any of these will give you about 5-8 times the intermediate zone of the Auto II or Comfort, and about 1.5x more reading. The Definity does have more reading than the Surmount by about 25% but it will depend on RX.

[shanbaum]

Essilor doesn't have a true freeform yet, so consider Shamir AutoII, Hoya ID, Zeiss Individual, and Kodak Unique.

That is incorrect, see, e.g., the Ideal.

[RKJ]

I tier Free Form lenses this way: Lowest tier is first generation Free Form, the optics are better but are not compensated for vertex, panto, and wrap. Regardless of sphere power and cylinder power, the lensometer measured Rx will match the written Rx. Next tier is Free form designed with published default values for vertex, panto, and wrap. There is a compensated Rx which will be different than the written Rx for high spheres, high cylinders, and high adds. The next tier is topography unique to each prescription with some default values and some customizable values. For example Seiko has a Wrap Tech where the wrap measure is required with the order. Again, there is a compensated Rx. The top tier is fully customizeable for vertex, tilt, and wrap - though if the optician does not provide the numbers, the program will use default values. With these criterea in mind, I study the lenses, quiz the reps, and tier lenses within any given brand. For Hoya, look at Lifestyle, In Style, and My Style. For the Physio look at Enhanced, Enhanced Fit, Enhanced Fit with Eye Code. Using this method you can tier the Reveal and also private label Free Form lenses independent labs are bringing to market.

I should add that you can tier Free Form lenses into good better best, however the 'best' lenses will have the same optics as the 'better' lens if the optician measures that vertex, panto, and tilt are very close to default values. Additional customization will yield the same optical result. Also, in low sphere powers with little cylinder and low adds, the good better and best are likely to be clinically equivalent in terms of optics. Use optics equations to calculate the compensated Rx to verify this is true. (I trust the optiBoard gurus to set me straight if I have any of this wrong. I love this group!)

One additional comment. I am of the opinion that the power profile from the fitting cross to the full add is a huge determinant of patient satisfaction. Some patients enjoy short corridor lenses, and some prefer longer corridors. Top tier lenses give the optician the freedom to order both a fitting height and a fixed segment height, and the optician can tailor the fixed segment height based upon the previous progressive min fit height and changes in prescription and the patient's report about what they wish they could improve over their previous progressive. From what I have seen, all of the great software programs for top tier progressives are taking a history including questions about the previous lens worn and patient satisfaction.

I hope this helps. I'd like to see a whole discussion around the concept of tailoring Free Form progressives....and it is possible I missed it. I haven't been on OptiBoard for a while.

Cheers,

[AustinEyewear]

I should add that you can tier Free Form lenses into good better best, however the 'best' lenses will have the same optics as the 'better' lens if the optician measures that vertex, panto, and tilt are very close to default values. Additional customization will yield the same optical result. Cheers,

That is an excellent point that I hadn't considered. Although you probably can not make a blanket statement like that, because the design may not be as good to begin with, although you would think it would be. I say this because even a non free form PAL might work better than this tier you refer to. So you could probably extrapolate that over to FF as well.

[Stephenpratt1990]

The Zeiss Individual and the Zeiss Gradal Top 3D are two freeform lenses that I deal with most often

[Tito]

Thanks for the follow up Tony. I'm furiously studying the subject right now. It appears that

Physio Enhanced FIT, Physio Enhanced Eyecode, and Ipseo Eyecode all take into account monocular PD, Fitting Height, Frame Wrap, Panto, VD and some the (special Eyecode/Head Cape/Posture) which would may place them in the category of a freeform.

Your gut feeling is correct.What will the big E do with millions of $$$ worth of front molded progressive lens inventory and equipment,they can't discard them over night,so they might as well ask their marketing gurus to keep on marketing their molded front side progressives ' Enhancing' them with back side digital surfacing.It's all about money


The DrX only accounts for PD, Fitting Height, but PAL is cut on backside. For what its worth, I would not consider this in the category of a freeform. To me, its more akin to a traditional lens being digitally surfaced on the backside, part way there, but no cigar. No ability to move the optimal reading zone around as one would normally do with a free form lense.


The others mentioned, all appear to be true freeforms, but then they have to throw a wrench into the equation by having this so called DUALOPTIX. As you mention, its hard to know what this would do. I perceive it as a "set" PAL on the frontside, with a "freeform" PAL on the back and it somehow compensates the front design. My gut feel concerning the molded PAL on the front, is that it would ruin the whole reason for going freeform in the first place, but what do I know about this subject, next to nothing, at least compared to the gurus :) To me, a big part of using a PAL freeform design is to provide the ability to adjust the corridor length and move the reading zone to the most optimal position in the frame, and it feels like a molded PAL on the front side would hamper the ability to do this?

Your gut feeling is correct.What will the big E do with millions of $$$$ worth on molded front side lens inventory and the equipment to manufacture it.They might as well ask their marketing gurus to keep 'marketing' their molded semifinished blanks,and so they came up with their 'enhanced' marketing theory,front side mold progressive with digitally surfaced,aspheric,atoric back side.You can do this with any other front side digital mold progressive brand.

[Tito]

Thanks for the follow up Tony. I'm furiously studying the subject right now. It appears that

Physio Enhanced FIT, Physio Enhanced Eyecode, and Ipseo Eyecode all take into account monocular PD, Fitting Height, Frame Wrap, Panto, VD and some the (special Eyecode/Head Cape/Posture) which would may place them in the category of a freeform.

Your gut feeling is correct.What will the big E do with millions of $$$ worth of front molded progressive lens inventory and equipment,they can't discard them over night,so they might as well ask their marketing gurus to keep on marketing their molded front side progressives ' Enhancing' them with back side digital surfacing.It's all about money


The DrX only accounts for PD, Fitting Height, but PAL is cut on backside. For what its worth, I would not consider this in the category of a freeform. To me, its more akin to a traditional lens being digitally surfaced on the backside, part way there, but no cigar. No ability to move the optimal reading zone around as one would normally do with a free form lense.


The others mentioned, all appear to be true freeforms, but then they have to throw a wrench into the equation by having this so called DUALOPTIX. As you mention, its hard to know what this would do. I perceive it as a "set" PAL on the frontside, with a "freeform" PAL on the back and it somehow compensates the front design. My gut feel concerning the molded PAL on the front, is that it would ruin the whole reason for going freeform in the first place, but what do I know about this subject, next to nothing, at least compared to the gurus :) To me, a big part of using a PAL freeform design is to provide the ability to adjust the corridor length and move the reading zone to the most optimal position in the frame, and it feels like a molded PAL on the front side would hamper the ability to do this?

Your gut feeling is correct.What will the big E do with millions of $$$$ worth on molded front side lens inventory and the equipment to manufacture it.They might as well ask their marketing gurus to keep 'marketing' their molded semifinished blanks,and so they came up with their 'enhanced' marketing theory,front side mold progressive with digitally surfaced,aspheric,atoric back side.You can do this with any other front side digital mold progressive brand.

[n711]

True and False.... Lenscrafters and Walmart uses discontinued Shamir lenses which means your patient cannot get the latest technology lens they offer from them
.

Thank you so much Gok!!! That makes much more sence than them getting the same product as us "independents" .... I wonder if the Wally-World or LC employees even know what they are using?????