Favored Free Form

[Andrew Weiss]

I very well may be wrong, but this is my understanding of all 360 series lenses...

They ALL start with the basic, pre-molded, all add on the front blank as their regular series. (i.e. a Physio 360 uses the same exact blank as a regular Physio) hence, no special identifier markings on a 360. The only way to know if you have a 360 is if you made it yourself, you take the lab's word it provided a 360. They are simply digitally surfaced. (back side)

All correct and verified by Essilor employees.

Fezz, which "other" lens I would use would depend on the patient; see my previous post.

And to follow up on Robert's post, which I found to be not only an excellent summary of properties to look for in a free-form lens but also of the various advantages/disadvantages of Shamir and Essilor's lenses: I agree that Shamir's base curves seem to be steeper than comparable Essilor lenses. Much as I love the Autograph, I generally find Shamir's steeper base curves and asphercity to be less comfortable than Definity's or Zeiss'.

[Barry Santini]

(Front & rear progressive surfaces) are two designs (that) are offset and rotated as well. The benefits are a wider intermediate zone, less peripheral distortion and the ground view advantage.
.

With respect to the surface astigmatism generated by *any* progressive lens design, Definity uses 2 surfaces to reduce the overall astigmatsim (through offset or rotation), thereby making the primary lens areas potentially able to deliver wider and sharpers areas of distinct vision.

aka "phase corrective"

Barry

[Pete Hanlin]

I wonder if Essilor is afraid of losing its semi-finished blank business by going to a 100% back-digital design. It would also make licensing their design on a per use basis a quandary, wouldn't it? I mean, how would Essilor know how many are sold if it can't count the blanks?
The usual disclaimer- I am an employee of Essilor.

Its hard to know where to start on this thread- but just a few observations...
1.) As Fezz noted, digital surfacing (freeform, whatever you call it) is a processing technology. In and of itself it adds next to nothing to the quality of a lens. The only benefit inherent to all digitally surfaced products is a very slight gain in precision (traditional processing has an inherent rounding error that averages 0.03-0.05 diopters, digital surfacing is theoretically capable of 0.01 accuracy).
2.) "True" digital surfacing is not equivalent with placing 100% of the progression and ADD on the back surface. For example, Hoyalux iD is digitally surfaced on the front and the back. DEFINITY has a portion of the ADD digitally surfaced on the back. Varilux 360 products have complex back surfaces which interact with and optimize the progression to the distance power of the wearer. Seiko Succeed is surfaced completely on the back of the lens. All of the above products are "digitally surfaced."
3.) The "format" of digital surfacing does not seem to have an effect on the visual performance provided by the lens. I happen to oversee clinical testing for Essilor of America. Independent sites (including several Optometry schools located around the world) have repeatedly found it is the DESIGN- not the process used to manufacture it- that determines the visual performance provided by the lens.

Looking around for other options is great and part of the ongoing process of providing your patients with the best products possible. That said, before making a switch based on digital surfacing, you should be aware that there are traditionally surfaced products available (from several manufacturers) that perform better than some of the "fully digitally surfaced" designs out there. The clinicals simply don't lie. To use a non-Essilor example, I would rather put my patients in a traditionally surfaced SOLAOne than in a Seiko Succeed.

Finally, where are you in the Keystone State? I'm originally from Colonial Park (between Harrisburg and Hershey).

[MarcE]

[COLOR=darkred]Independent sites (including several Optometry schools located around the world) have repeatedly found it is the DESIGN- not the process used to manufacture it- that determines the visual performance provided by the lens.

Thanks Pete, very informative and relevant. Although you don't need my humble endorsement, I tend to agree based on my limited experience.:bbg:

[randletibbs]

While all the lenses you mentioned do use digital surfacing technology, the only one in your poll that is truly a personlized freeform lens is the Autograph II which is a backside design and Rx.

[Fezz]

Randle,

Welcome to Optiboard!

:cheers::cheers::cheers::cheers:

[Andrew Weiss]

First of all, welcome to OptiBoard, Randle. Having another ABOM on this board is a real gift; I appreciate your taking the time to join this community.

Now, to Pete's post. After reading that, and comparing it to my experience, my perspective is that there is truth in both what Pete said and in the continuing interest in free-form processing. In other words, free-form processing may not give you a great lens unless there's a great design. And, similarly, if you have a great design freeform processing will enhance patient vision, comfort and acceptance.

Example: we're a Vision Source office and use Essilor's VSP progressives, the TruClear and TruClear HD (You can read "Accolade" and "Accolade Freedom" for those two without much trouble. ;)). TruClear is a digitally designed, traditionally molded front surface with a traditionally ground backside; the HD has the exact same front surface and has a free-form digitally-surfaced backside optimized for position of wear and frame dimensions. Acceptance of the TruClear HD is greater than of the TruClear; we get more "Wow" with the HD, more "This feels natural and right", than with the TruClear. You could take the same Rx and make up a TruClear and a TruClear HD and the patient will almost always prefer the HD. That's the benefit of the digital-free-form backside.

Fezz mentioned Darryl Meister's article in the October 20/20, and I second his recommendation to read it. It's a great primer on how free-form surfacing allows us to optimize progressive lenses for a variety of factors, from unusual Rxs to position of wear to unusual facial features or musculature. I'd only add Pete's point: you have to have a great progressive lens design to start with.

I don't wear the Seiko Succeed (the last Seiko I wore was the P6 and it gave me a headache), so I can't comment on the quality of the lens design. I can say, from my experience and those of our patients, that the Autograph II has a fine design, as does the Zeiss Individual.

[Robert Martellaro]

Looking around for other options is great and part of the ongoing process of providing your patients with the best products possible. That said, before making a switch based on digital surfacing, you should be aware that there are traditionally surfaced products available (from several manufacturers) that perform better than some of the "fully digitally surfaced" designs out there.

Right. Garbage in, garbage out. Also known as polishing the turd.

[HarryChiling]

Right. Garbage in, garbage out. Also known as polishing the turd.

GIGO Turd. It's not the first or second but the turd version of the FezzJohns, Inc. digital progressive, right? :D Hey Pete I'm from Shrewsbury in the York area next time your in town let someone know so we can get you sloshy drunk and get all you essilor secrets on how to rule the world. :cheers:

[HarryChiling]

Pete,

The 360 lenses, are they conics on the back side or is it a deformed conicoid? I have yet to get an answer as to what gets factored into the backside correction of the 360 designs, is it just clean up on the difference in base curve or do they factor more. Also how come the F-360 factors in dihedral and panto but the US version don't require this information from the optician placing the order? Does the US version use a global default for dihedral and panto?

[Fezz]

Hey Pete I'm from Shrewsbury in the York area next time your in town let someone know so we can get you sloshy drunk and get all you essilor secrets on how to rule the world. :cheers:

I am always in for a little road trip. I may know a place or two to splash our gullets!

;):cheers::cheers::cheers::cheers::D

[Jacqui]

I am always in for a little road trip. I may know a place or two to splash our gullets!

;):cheers::cheers::cheers::cheers::D

You would !! :D :D

:cheers:

[ayoco]

you want to try www.profitoptix.com

[Jacqui]

you want to try www.profitoptix.com

Prices seem high to me.

[icare]

Does the US version use a global default for dihedral and panto?

Could someone please enlighten me to the meaning of dihedral in lens fit? Is that another term for face-form? Thank you for your clarification.

[HarryChiling]

Could someone please enlighten me to the meaning of dihedral in lens fit? Is that another term for face-form? Thank you for your clarification.

you ot it doc, they use dihedral in the UK in the F-360 so I used that terminology it's actually the most accurate since in geometry the reference to the angle between two planes is the dihedral angle.

[ayoco]

if you register on my web site www.profitoptix.com (there is no charge or obligation) you can see the costs of a lot of different free-form and availabilities to help you choose. say hello to me under comments.

[Ginster]

Just got my Hoya ID today, I love this lens, I wear 3 diopters base in with combining o.d. base down and o.s. base up, I have no distortion, really, It's great, I had the WOW Factor for the first time ever in a progressive.:)

[gravyharp7]

Would you call Autograph II an aspheric lens? It is listed as having a spherical front surface...
If not, does it then lack the advantages of an aspheric lens, or is this overcome in their technology?

[Jacqui]

Would you call Autograph II an aspheric lens? It is listed as having a spherical front surface...
If not, does it then lack the advantages of an aspheric lens, or is this overcome in their technology?

Minus curves are atoric, works the same as aspheric.

[allanon]

Kodak Unique.