Zeiss Gradal Top vs. Varilux Panamic

[Robert Martellaro]

This is from my notes when I compared these lenses a couple years ago(along with others) using the same frame and Rx at 22 high -4.50 dist add 2.00.

Top- initial comfort good, clear distance periphery, long corridor requiring chin lift to clear the text at the middle of page.

Panamic- Initial comfort good, blurred distance periphery, short and/or quick corridor requiring little if any chin lift for the middle of page.


Spexvet,

I had a similar experience with the Image. The initial comfort was poor and felt like the least refined of the bunch. Maybe I got a bad lens also. Maybe it works poorly with minus Rxs. Maybe there are better choices.

Robert

[Spexvet]

Virtually all of my "rejects" come from changing PAL brand. As much as I want to give patients the very best, I have anxiety every time I change brands. My "cheap" lens of choice is the Sola XL. I have had most of my "rejects" swithching from XL to Panamic. I suppose the lens is just too different. I have a patient who came to me wearing VIPs. Other "chain" opticians have fit her with Adaptar and Natural, and she came to me to find out why she couldn't see. I put her back in VIPs and voila! she was happy again. I have also had issues switching patients fron Outlook to Ovation. Go figure.

[Pete Hanlin]

Sure... As you indicated, I'm sure everyone in OptiBoardom is faithfully using CRP (Corneal Reflection Pupilometers) to measure monocular PDs when fitting progressive addition lenses. Unfortunately, between 33-40% of opticians still use binocular PDs (e.g., 63/60) when ordering PALs- I know, because I've monitored this at various laboratories.

Even when the pupilometer is used, I've found that between 20-40% of pupilometers out there are off by >=1mm in one or both eyes. This isn't surprising, given the abuse that a CRP is exposed to over the months and years in the busy dispensary. CRPs can be checked and calibrated to make them accurate again- I think I've posted the "how to" before, but I'll be happy to post it again.

Given proper monocular measurements, I'm consistently amazed at how many PALs are fit either "a couple mm high" (or low). Pupil center is truly the proper location for the fitting reference point- with a few notable exceptions... Also, vertex distance (low as possible, but no more than 12-13mm), pantoscopic tilt (8-12 degrees), and face form need to be in proper proportions.

I know these things are basic- but they are performed on a shockingly sparse percentage of PAL fits in the US market. Everyone tells you they are "doing it correctly," but when you ride along with consultants and watch opticians in practice- or evaluate eyewear that has been sent in because the patient "just couldn't get used to them," the lack of proper fitting technique becomes glaringly obvious.

Considering all this, I reaffirm my earlier comments. Namely, nearly ANY PAL design is quite capable of delivering at least somewhat comfortable and adequate vision if fit properly. Having said that, I do believe there are demonstrable differences between individual designs from manufacturer to manufacturer. A lot of the differences evolve due the unique design philosophies and design processes of each manufacturer. I happen (not surprisingly) to beleive that the approach and technique of Varilux has provided some of the "best" PAL designs available. There are- with no doubt- other fine designs out there from companies such as Zeiss, Rodenstock, Sola, etc. There are also some- in my opinion- not very sophisticated designs out there as well (but as we've asserted, nearly all of them are quite capable of producing decent vision in the hands of a skilled optician).

[Fezz]

Thanks Pete!

Fezz :cheers:

[drk]

I second Fezz's request, Pete. Dot the pupil, use a lensometer. Minimize vertex at dispense, make sure panto is correct, watch the fitting reference point. What's missing?

Ok, I'm a liar. I admit I DO CHEAT by ordering the fitting height 1mm below what is measured. Sorry.

Shamir's lenses: very, very, good. Neat, simple, company. Not sexy. Good materials. Outstanding price. Justifiable for a primary family of lenses.

[Pete Hanlin]

I believe the Vision Print System(TM) that has been developed by Essilor after numerous years of R&D is going to eventually have a significant impact on the way we select PAL designs for our patients.

I've described it before, but to recap the device measures the ratio and consistency with which a patient uses head vs. eye movements to view peripheral objects. Turns out each of us has a well-developed, consistent, and individual head/eye ratio, and I believe this affects how we perceive various PAL designs.

You're correct, drk, there really shouldn't be all that much to properly fitting a PAL lens. Unfortunately, I've had the opportunity to observe quite a number of fits in numerous offices and locales, and I'm sad to say good fitting technique is not the norm out there.

Assuming a good fit, however, I believe future advancement in PAL design is going to come more from a better understanding of the visual ergonomics of the individual wearer and less from advances in PAL design itself. The advances in design will come less from advances in polynominals and more from advances in matching design features to the individual's visual physiology.

[karen]

I know these things are basic- but they are performed on a shockingly sparse percentage of PAL fits in the US market. Everyone tells you they are "doing it correctly," but when you ride along with consultants and watch opticians in practice- or evaluate eyewear that has been sent in because the patient "just couldn't get used to them," the lack of proper fitting technique becomes glaringly obvious.

I agree. One of the things I find that makes a difference is getting on "eye level" I am a tall girl and when sitting am taller than most patients. I learned early on my measurements were consistantly off. Once I lowered my chair or even got down on my knees in front of the patient I had much less adaptation issues. I also would dot center pupil and then make them sit back, relax and talk to me for a minute to see if that's where the mark really was. Alot of patients tense up when you do something official like measurements. My Zeiss rep taught me a great trick-after making the dot, you can like the edge of the marker(where the cap stops) up on an edge and draw a line (that is very straight because the marker is stationary) put the frame on the patient-if they are looking above or below the blue line chances are good it is not center pupil.

[Andrew Weiss]

Pete, I'd add a couple of things:

-- Panto and vertex can have a dramatic impact on wearer comfort. And it seems each lens has its own ideal panto tilt. Too little, and the patient doesn't find the reading zone. Too much, and the patient gets distorted distance.

-- While I agree that fitting at the pupil center is what we're supposed to do, I find myself in an office where the vast majority of our multifocal wearers want the fit at the pupil base. This corresponds to another oddity about this office, which is that virtually all of our bifocal wearers want the seg 5mm below the lower lid. We seem to have a preponderance of folks who want that reading/intermediate Rx out of their line of sight. Rarely do I have complaints that the patient has to hike down to far to find the reading area or intermediate. Interesting.

-- A surprising number of people have vertical assymetry with their eyes. When my dots show uneven height, I don't assume I've made a mistake, I try to verify it with the patient's face.

-- I don't trust our pupilometer completely; if I get a reading that doesn't look right to me as I'm looking at the patient's face, I'll redo it with a center-bridge PD ruler to see if it's close.

-- I also agree that the later generations of progressives require more care in fitting than the earlier, hard-design ones.

-- And I move someone out of the progressive they're already wearing with some trepidation and infrequently. When I must (because, for example, the patient wants a slim frame and is wearing an Adaptar), I try to find a lens that is close enough in design so the patient won't experience too much difficulty. Even with that, it's iffy.

[omisliebling]

Varilux are much easier to sell because of the name recognition factor.

I tell my patients about the german engineering of the Zeiss lenses and about 99% are willing to give it a try and most of them end up liking them more than Varilux or about the same. Since I don't wear any glasses I can only go by the patient's input and the satisfaction rate which so far Zeiss beats Varilux.
I'm a proud german and love Zeiss lenses :hammer: but I also have very good luck with Image. I strongly believe patient satisfaction also depends on the optician's attitude and patient relation. I explain in simple terms and have lots of fun and laughs with the patients at the same time, I LOVE what I'm doing (until the boogy man or woman walks through the door, luckily doesn't happen a lot :) )