Does anyone have experience with both of these lens and how they stack up against each other? Is one distinctly "better" than the other for your traditional PAL wearer.
Does anyone have experience with both of these lens and how they stack up against each other? Is one distinctly "better" than the other for your traditional PAL wearer.
One of the reasons I ask this question is we have had some issues with the individual lens in high minus (0ver -5). We use this lens in our "Best" category and proclaim its the Best progressive money can buy. If I'm going to have patients pay a very high amount for this superior lens I can not have them coming back. Therefore, I've started looking into the Hoya ID lens as an alternative. Thoughts?Originally Posted by mpuzio34
I'd suggest discussing this issue with your ZEISS Individual laboratory or representative. Since Individual has one of the widest distance zones available in a progressive lens, high myopes actually represent some of the most satisfied wearers...One of the reasons I ask this question is we have had some issues with the individual lens in high minus
Best regards,
Darryl
Darryl J. Meister, ABOM
I concur with Darryl (how hard is that ever?).
I fit plenty of high myopes in the Individual with fantastic results. The key is to not think in terms of "Good, Better, Best". I've fit patients with all sort of lenses after having a conversation with them about the way they use their eyes. This is regardless of the cost unless otherwise specified by the patient or the ODs. I'm not sure how much leeway you have but I fit everything from Hoya to Shamir to Seiko to Zeiss. I don't necessarily have brand loyalty- everything performs as uniquely as the patient I'm fitting.
"Strictly speaking, there are no enlightened beings; only enlightened activity." -Shunryu Suzuki
The Zeiss Individual is a T shape progressive, which emphasises distance wear across the 180, in those patients that need distance its a very good lens. The Hoya ID is most often a Plus + shaped pattern with very good intermediate and reading. However, in patients with low prismic tolerance, the distance zone is often very narrow. Hoya essentially places prism in the top corners of the lens to reduce geometric distortions. Some people, like me, end up with a very narrow distance zone (a few don't). The Seiko Surmount however, much offers a wider distance and intermediate than the ID, but slightly narrower reading. So it gives you a cross between the two.
These lenses are all great... but only if you fit them well, and on the right patients.
I could spend a $1000 on a Titanium Gold Driver with a moon rock for balance. But if I try to use that club on the putting green, it will suck. I am better off grabbing a putter off the mini-golf course. Same with progressives, we need to know how and when to use them, or it doesn't matter which one is "best".
Bottom line is we have a master optician doing our measurements so that is not the issue. I have talked to our reps and they have no answer for me. Every time my optician inspects these supposed great progressives they have significant edge distortion in High Myopes (over -5), and the patients will also experience this. I know for very high minus the lens are sent to Germany and those have come back with very inferior quality. We end up putting them back in their supposed inferior varilux product and they see fine. Doesn't make my practice look good....
I am just curious here. Are you taking frame wrap, panto, and vertex measurements?
No, we are using the default measurement however we getting the I Terminal this week which will automatically calculate the wrap, panto, and Vertex distance. Don't know if that will help....
As I mentioned above, Zeiss Individual lenses have almost zero optical astigmatism above the 180 line. And every lens is redesigned using the exact prescription parameters to preserve this optical performance for every wearer. I'm not aware of any other progressive lens on the market that can make the same claim, although I'm sure that a few of the better quality designs come close.I have talked to our reps and they have no answer for me. Every time my optician inspects these supposed great progressives they have significant edge distortion in High Myopes (over -5), and the patients will also experience this.
The Clinical Research Center at UC Berkeley conducted a blind, randomized wearer trial comparing Zeiss Individual to traditional progressive lenses. Zeiss Individual was preferred on average to traditional progressive lenses, including Varilux lenses. And Zeiss Individual lenses currently enjoy a progressive non-adapt rate of only 0.5% among our processing laboratories, so the lenses continue to perform consistently well in the marketplace.
Nevertheless, if you are noticing significant "edge distortion" in Zeiss Individual lenses, it could be due to a number of possible factors, ranging from the low Abbe value of high-index materials to improper position of wear measurements. The surfacing and fabrication quality of the lenses should also be verified. Zeiss Individual lenses are all surfaced in the US, with the exception of 1.74 high-index lenses, which are fabricated in Germany.
If you have tried to discuss this issue with your CZV representative, to no avail, please feel free to email me your contact details and location, and I will ensure that someone from your Individual processing laboratory looks into this issue for you. In the meantime, if you are suspicious of the product coming out of Germany for some reason, although their lab operates to even higher standards than our local labs, you can always order your Individual lenses in 1.60 or 1.67 high-index, which are made in the US.
Best regards,
Darryl
Darryl J. Meister, ABOM
Only the high pluses, and 1.74s are done in Germany. The edges will contain variable asphericity so it may appear as distortion looking at the lens in your hand. Darryl can run (or have run) a comparitive lens map to see if the actual lens is made as its supposed to. If there is a problem, its likey with your local Zeiss distributor, not with the lens or design itself.
I wouldn't put all my eggs in that one basket. We had a demonstration of the iTerminal in our office about a year ago and the whole thing was a comedy of errors. I love the Individual but I (read, my ODs) don't feel the need for the equipment. I've had many satisfied patients of whom I've measured manually. I have to admit, I'm a little surprised that your master Optician would feel comfortable just winging it with default measurements given all the components of customization for the lens.
"Strictly speaking, there are no enlightened beings; only enlightened activity." -Shunryu Suzuki
Yeah, it's not hard at all to manually measure panto and wrap. Our Zeiss rep gave us an inexpensive tool to measure panto and a very simply guide to measure wrap. Very easy to do but it improves results.
The iTerminal is mainly for theatre I suppose. I would always double check all of its measurements. For me the new Hoya ID Lifestyle is an amazing lens. The most successful I've fitted (we've done 40 pairs @0% non-tol). Zeiss have excellent products as well, but we rarely use the Individual.
I have been test driving the individual myself so that I know what to explain to my customers on it's best features.... but I don't seem to be as impressed as I
expected. I see just as well out of my Varilux Physio Enhanced, and I guess I had expected more out of this lens. I also have been doing the default because
we don't have the iterminal. They made a mistake and sent me the Ind for midrange... and noted that that was a wonderful lens though I need more near. I
am currently in the regular Individual and also found out that it is a 6 drop and being use to wearing a 4 drop progressive I am continuously pushing up my frames
to get in my near. My seg ht is 18.... So though I am still selling both I wish I had a better experience with this lens.
Please keep in mind that the "drop" is simply the location of the prism reference point for verifying the specified prism in the lens. It is not really associated with the actual design of the lens or the corridor length at all. ZEISS free-form lenses, including Individual and GT2 3D, utilize the standard ZEISS "drop" of 6 mm, which among other things achieves certain surfacing outcomes.
Further, while the "drop" of ZEISS Individual is 6 mm, the prism reference point is located 2 mm below the geometric center of the lens blank. Most progressive lenses with a 4 mm drop, on the other hand, typically have the prism reference point at the geometric center. Consequently, there is really no physical difference between the locations of the progressive optics on either type of lens, just a difference between the locations at which we instruct the eyecare professional to verify prism.
The corridor length for ZEISS Progressive Individual 2 is determined by the fitting height and whether you select the Balanced, Intermediate, or Near lens design option. If you prefer a shorter corridor length, in general, you may prefer the Near lens design option, which has a higher near zone.
Prior to the clinical wearer trial conducted with ZEISS Individual lenses by the Clinical Research Center at UC Berkeley's School of Optometry, the CRC researchers performed a repeatability and reproducibility study that compared i.Terminal measurements to traditional fitting techniques. The i.Terminal performed well in this study.
Similar studies using have been conducted in Europe over the years, several with Video Infral (the predecessor of i.Terminal), with equally impressive results. If you are experiencing what you suspect may be reduced accuracy with your particular i.Terminal, I would recommend contacting your Carl Zeiss Vision representative for some troubleshooting support.
Best regards,
Darryl
Darryl J. Meister, ABOM
Darryl, that was not meant as a criticism. The iTerminal looks great. We don't have one but are at the moment deciding between that and the Hoya measuring device (by the way, could you explain the significant differences between the two?). The main reason we 're getting one is not to improve our accuracy (although I'm sure it will, but we will still double-check it!) but to generate theatre and to impress patients, and thus to set us apart from our competitors.
I didn't take it as one. But if you do indeed feel the need to double check the measurements, I was just assuming that you have had some sort of issue with the accuracy of the instrument, which I'm sure could be resolved.Darryl, that was not meant as a criticism.
I haven't actually seen the HOYA instrument yet; I'm assuming that it is relatively new to the US. If I run across any information on it, I'll try to remember to post my observations in this thread.Hoya measuring device (by the way, could you explain the significant differences between the two
I'm sure that HOYA makes a good product.. For me the new Hoya ID Lifestyle is an amazing lens.
Best regards,
Darryl
Darryl J. Meister, ABOM
Darryl,
I actually had the near one as well, but lens was off. Actually had to have these lenses made 3 times, one because they sent me the wrong one, (mid) though it was a mistake
I appreciated trying it for my customers. Wanted the near one, and had issues with one lens... So they talkd me to tryinging the Balanced one. The near I had to keep pushing it
up even with an 18 seg ht. Same thing with the Balanced.
Donna
Just Curious Donna, were any of the three lenses fit to center pupil? I have a tendency to fit the Varilux products just a smidge low, but not with the Zeiss products. I'm sure your have your own method preferences for fitting, what ever makes you comfortable. Also curious as to whether you had pow measurements done for any of the 3 lenses you had done? That may have a factor in your impressions of the lenses.
Darryl,
Mabye it's just a bit off topic, but the prism reference point on Zeiss product being lower than the geometric center is something I wasn't aware of. Is it to improve wearer comfort as they move through the corridor or is it related to prism thinning and cosmetics? Should prism thinning be avoided with Zeiss progressives? Thanks in advance.
-jh
From a product marketing perspective, there was probably some desire to differentiate early ZEISS progressive lenses from competitors. But locating the prism reference point at 6 mm below the fitting cross, instead of 4 mm, also provides certain optical and mechanical advantages in some cases.Mabye it's just a bit off topic, but the prism reference point on Zeiss product being lower than the geometric center is something I wasn't aware of. Is it to improve wearer comfort as they move through the corridor or is it related to prism thinning and cosmetics?
First, lowering the prism reference point better balances the prismatic effects between the distance and near zones of the lens by positioning the optical center of the lens closer to the midpoint between the two zones. This reduces vertical prism imbalance at near in anisometropic prescriptions and also minimizes lateral chromatic aberration at near.
Second, lowering the prism reference point reduces the center thickness and the thickness difference between the upper and lower edges of the lens blank in the absence of prism thinning, particularly in higher add and plus powers. It also moves the edge of the surfacing block farther from the near zone, reducing the likelihood of blocking waves encroaching the near zone.
That said, the "drop" distance to the prism reference point has nothing to do with the corridor length or the distance to the near zone, which seems to be a common misconception.
Carl Zeiss Vision still recommends prism thinning for ZEISS progressive lenses in order to maximize cosmetics and comfort.Should prism thinning be avoided with Zeiss progressives?
Best regards,
Darryl
Darryl J. Meister, ABOM
Sharpstick 777,
I did the same. I fit Minus (-) lenses with Zeiss individual 2, Plus (+) lenses with ID mystyle and SO FAR SO GOOD. I did try to fit Zeiss Individual 2 with Plus lenses and NO SUCCESS and so many redo which frustrated us and the patients.
Daryl,
I got training from Zeiss rep to use I-terminal for MANY TIMES and the redo is EVEN higher than when I do manual measurements to order Zeiss Individual 2. I am about to give up on using I-terminal, instead i do manual measurements more often now. I don't know what did I do wrong? Is there any I-terminal handbooks out there for me to read and learn how to use the machine better? Thanks.
P.S: I know the i-terminal is very easy to use but why my redo rate is higher than when I did manual measurements? I am sure I did not use the machine correctly. Thanks.
If we use prism thinning, we are essentially creating yoked prism at the distance OC, BD or BU depending on power. In low powers this won't be a problem. But in Sheedy's study of yoked prism (for vision therapy) he found loss of visual accuiity in yoked prism as low as 2D, but its subjective, some patients didn't experience loss later, but it became universal at 4D, almost everyone had a loss of VA.
We have assumed for years that prism is only a problem if its unbalanced, but Sheedys work would seem to repudiate that.
So at some point, using prism thinnning, in some powers, won't some patients experience a loss of DVA? I know in my own experience I have seen this happen. Some manufacturers are using varying degrees, or even zero prism thinning in their free-form lenses. Does Ziess vary their prism thinning based on power? Or is it the same for every lens?
I assume that you're referring to the following study: Sheedy, J. and S. Parsons. "Vertical yoked prism—Patient acceptance and postural adjustment." Journal of Ophthal. Physiol. Opt. Vol. 7 (1987), pp: 255-257. Sheedy and Parsons actually found that subjects experienced no issues with 2.0 prism diopters of base down prism:
"Twenty-three subjects wore spectacles with no vertical prism and also with bilateral vertical yoked prism. The subject population could not significantly differentiate between 2 PD base down and 0 PD. There was a nearly unanimous rejection of 4 PD base down. Postural changes were significant during 4 PD wear but not during 2 delta wear. The results suggest that 2 PD may be accepted by most patients, but 4 PD will not."
Consequently, it is very unusual for laboratory software systems to apply more than 2.0 to 3.0 prism diopters of prism-thinning. You can read more on the subject in my old article on OptiCampus, Understanding Prism-Thinning.
The prism-thinning used by larger laboratories with expensive software packages generally calculates the precise amount of prism required to balance the upper and lower edge thickness of the lens by considering factors such as the distance prescription, add power, fitting height, decentration, frame shape, et cetera.
When the instrument is used correctly, you should achieve more accurate and reliable measurements. This has been confirmed in independent clinical studies. It is possible that something in the instrument is out of calibration, which can and should be addressed. And you'll want to make sure that it has been installed and leveled properly.
Otherwise, if you can elaborate on the type of i.Terminal measurements in which you generally notice the greatest deviations from your manual measurements, I can certainly provide you with some specific recommendations to improve your results.
That said, if you feel that you have not been trained enough on i.Terminal, I can speak to the local CZV trainer or representative for you to try to arrange for some follow-up training, if you can provide your contact details to me via email or messaging.
Best regards,
Darryl
Darryl J. Meister, ABOM
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