What Lens are truly Freeform?

[RKJ]

I've tried moving a couple people from the comfort to the Auto II, unique, etc... and most I've had to switch back?

This representative was incredibly knowledgeable when I was looking at similar challenges.

Jerry Thornhill Technical Services

Shamir Insight, Inc. | 9938 Via Pasar, San Diego, CA 92126 T: (858) 444-3863| C: (858) 740-6518 | F: (877) 285-4863 jthornhill@shamirlens.com Jerry said successfully moving patients from Comfort to Autograph II is a challenge, and that the Spectrum design is especially good for these patients and also for patients with higher plus prescriptions. You might want to talk with him. I had a lengthy conversation with a Kodak Unique rep at Vision Expo East. My contention is that the software does not allow the optician to tailor the lens. All big frames get long corridors by default, even if the patient has successfully and happily worn a short corridor prior to the Unique. In my opinion, that is the reason so many offices experienced failure with Free Form when they tried to move patients wearing traditional Essilor lenses to Kodak Unique lenses. The rep essentially explained that the optician should always put the patient into the longest corridor possible, for Every Day progressives AND sell second pair computer progressives. I was not persuaded. Personally, I greatly prefer to wear short corridor lenses. AND, I believe ECPs should have a well defined comprehensive product mix with Free Form lenses a skilled optician can tailor to the patient rather than letting the software tailor progressives to the frame selected. Because so many offices have had non-adapt problems with Kodak Unique, it is not high on my list of favorite lenses.

[spekladie]

I am also a huge fan of the the Zeiss Individual lens. I have had great success with fitting this lens.

[RKJ]

I am also a huge fan of the the Zeiss Individual lens. I have had great success with fitting this lens.

Thank you SpekLadie.

I did not mean to sound like I am promoting Shamir, though I did mean to sound less than enamored with the Kodak Unique. I prefer lenses that allow the optician to tailor the Free Form power progression.

There are many Free Form progressives that can be customized. Zeiss, Seiko, Shamir, Hoya, and independent labs with private label Free Form lenses - All have Free Form lenses that allow the optician to specify the fixed fitting height.

[Mark Mattison-Shup]

Just saw this post and thought I'd add 2 cents.

Freeform and digital surfacing are manufacturing methods that can accomplish a designers targets for their lenses. The levels of "freeform" that was the original request of the post for good, better and best for me are defined by the level of optimization i.e., combined progressive and Rx, atoric, optimized (compensated for peripheral errors using default fitting values), fully optimized using position of wear values, personalized adding either wavefront, lifestyle or head turn, eye mover, eye center rotation distance. However, the success of the designs are still based on the original designer's (companies) design philosophy.

I added a variety of posts on this on the Opticians Handbook (opticianshandbook.com) Freeform pages. You might find the information helpful in addition to these posts.

Mark
Mark Mattison-Shupnick
Dir., Education and Training, Jobson Medical Information LLC

[Robert Martellaro]

My contention is that the software does not allow the optician to tailor the lens. All big frames get long corridors by default...

Not only that, but for narrow frames, the software will decrease the corridor length for those who rarely read with their eyeglasses (distance -2.50 DS Add +2.50). Many PALs do this now, including those from Zeiss, Essilor, Shamir, and others. At least Shamir offers a fixed lens for those dispensing opticians that are giving some thought to what this all means, from the wearer's perspective.

The rep essentially explained that the optician should always put the patient into the longest corridor possible, for Every Day progressives AND sell second pair computer progressives.

That's what I do with my eyeglasses, and for most of my clients (Adds over +2.00) who have significant intermediate tasks. I wouldn't necessarily use the longest corridor, but I would choose a PAL design that had above average distance vision, something you won't find with any of the more aggressive short corridor PALs.

[Peter J Shaw OD]

Kurt, could you please clarify what you define as "compensated"? There is some word in the market that only Free-form lenses that offer "customized" vertex, face form and panto calculations are truly better. However, I have seen usage studies from both manufacturers and universities where only about 11% of patients benefit from those advanced compensations (Essilors says 9%).

All true-free form are compenstated with at atoric, base curve, ect, and most use standard averages of tilt and vertex. So when you say "compenstated" are refering to the standard ones, or the fully customized ones?

And if you mean that only the highly customized compensated lenses are better, do you have any usage studies your company has done (or at least read) to support that? Right now the ones I have seen do not.

Perhaps I can help you, IOT supplies true freeform software to manufacture lenses so that the lens performs like the Rx that the OD prescribed no matter what the position of wear plus they have many design options to meet the lifestyle and ergonomic needs of the patient. IOT are one of the true free form companies, Rodenstock also comes to mind with their new offerings. Another point IOT is 50% owned by Younger so I guess that they are at least half American (if that's important)

[sharpstick777]

Mark Mattison-Shupnick
Dir., Education and Training, Jobson Medical Information LLC

Welcome to Optiboard Mark... how were you never here before?

[Peter J Shaw OD]

Our lens design considers the position of wear and tailors the full reading zone of our standard lens to start at 23 degrees downward gaze, it is independent of the depth of the frame but requires the fitter to establish the face form, vertex and pantoscopic angle.

[Mark Mattison-Shup]

Thank you Robert M. and yes you are correct. Many of the lenses that are optimized use the fitting height and B of the frame to deliver a corridor length that is manufacturer determined, not dispenser chosen. As a result, as you and others have found out that a patient moving from a short corridor molded lens may in a freeform replacement, in a larger B frame get a longer corridor. The result is a chin up, tilt to get to the reading.

As you and Peter S. point out, the higher the add, the more important that the corridor not be lengthened since the need of the over +2.25 Add wearer is a shorter (me being one of them) rather than longer path to reading. With no reserve reading needs to be where it is comfortable. So, the onus is on the dispenser to really understand the lenses that they are using. If the frame is larger, the corridor will usually be longer so record the design used in the habitual eyewear, then understand if the patient was happy. You might be doing them a favor lengthening the corridor for available intermediate, but they will notice the difference.

The design options are large and as most on this forum know, just being a freeformed lens does not mean that the lens is any better. Digitally enhancing lenses is an opportunity for opticians to differentiate themselves from the online sellers. In fact, as I usually teach in classes I'm fortunate ot present, optimized single vision is the better opportunity. In progressives, there's still unwanted error that we must manage.

Sharpstick - been lurking at times in the background. As you know, there's limited time to participate everywhere. Thanks, Mark

[Diopterman]

Our lens design considers the position of wear and tailors the full reading zone of our standard lens to start at 23 degrees downward gaze, it is independent of the depth of the frame but requires the fitter to establish the face form, vertex and pantoscopic angle.

What should the "fitter" use to accurately measure those values?

Do you provide a high quality measuring tool to do these measurements?

[sharpstick777]

As you and Peter S. point out, the higher the add, the more important that the corridor not be lengthened since the need of the over +2.25 Add wearer is a shorter (me being one of them) rather than longer path to reading.
Sharpstick - been lurking at times in the background. As you know, there's limited time to participate everywhere. Thanks, Mark

Mark, If you shorten the corridor, in a higher add, you can reach a point where you effectively destroy the intermediate. Although its easier to get the reading in a short corridor lens (and the reading effectively larger) its at the cost of mid-range and intermediate. Each step just gets too small to be useful, like a set of stairs where each step is only an inch.

Many of us use the intermediate far more than our reading, cel phone use and all.

[Mark Mattison-Shup]

Mark, If you shorten the corridor, in a higher add, you can reach a point where you effectively destroy the intermediate. Yes, wearing a 2.50 add now demonstrates the variety of manufacturer's designs that work better or worse than others for intermediate. No argument that too short is ineffective for intermediate but its the "Goldilocks" design that works for me, not too short, certainly not long, just right. Regardless, they are all general purpose and I wear computer progressives at the laptop.

Since the thread started about freeform and the variability of the received corridor length, having a maximum length, regardless of B unless otherwise stated is a reasonable attribute (Thanks Peter).
Mark

[RKJ]

What should the "fitter" use to accurately measure those values?

Do you provide a high quality measuring tool to do these measurements?

This is a two part response:

1. I am very interested to know what tools offices are using to take vertex, panto, and wrap measures. I know of the Shamir panorameter kit. Does anyone here have top of the mind knowledge of all of the hand held and automated options for taking these measures?

2. Peter, like Diopterman, I am interested to know how you are teaching methods for taking measures accurate enough to ensure the most natural visual experience through the lenses.

It has been my experience that the expense of automated tools is one of the hurdles to widespread acceptance of Free Form lenses. I anticipate that this challenge is a problem for independent designers like you, especially with the growing success of automated tools, and growing belief that they are necessary for providing best possible measures.

Having said that, Free Form lenses have wider sweet spots and should be more forgiving of small measurement errors than conventional progressives. Peter, what is working best for you, and if possible, any tips on what to avoid?

[opticallens]

[Diopterman]

[ATTACH=CONFIG]8600[/ATTACH]

Do you have a picture of a left lens to confirm that these are truly free form?