1.74 Varilux progressives. How good are they?

[Lemon]

The jury is still out on the 1.74 lenses, in my opinion. I haven't fit too many people with The 1.74 Panamic, but due to its aspheric design the power I see when I look at them in the lensometer is different from the patient's distance Rx. I was warned of this by both the rep, and by my grinding facility, who include with every order a printout of what their lab allegedly saw when they neutralized the lenses.
In several instances what I saw was dramatically different from what the lab's printout was. In both cases, I decided to dispense the lenses, adjust them properly, cross my fingers, and evaluate the distance, near, and intermediate acuities. In both cases, there were no complaints, and VA (as reported using a Varilux reading card) was perfectly fine.
Perhaps all's well that ends well, but I still have a problem with this. I can't leave quality control to chance, and hope that someone else has done their job.

Has anyone else had issues with the 1.74 Varilux lenses like I have had?
Or should I just keep on crossing my fingers?

[For-Life]

Just fit up one to a first time presbyope yesterday. Before he bought them he was scared of PALs. He walked out with them with absolutely no trouble.

[TheEyesHaveIt]

Sorry for this silly question....

What is a "PAL"?

I'm guessing...Progressive, ?, Lens. Ten points to the first right answer!!!

Thanks in advance.

Sincerely,
Acronym Challenged

[Lemon]

PAL - (n) someone who will loan you money, go to the game with you, and never let you down. Also, a PAL can be a Progressive Add Lens.

The customer who I spoke about who ordered the 1.74 index Varilux Panamic lenses came back to pick them up last night. She was amazed with how thin they were. She was very happy with the adjustment. But alas, she could not see properly.

This crated for me a difficult situation. Since I was unable to verify the prescription in the lenses, I didn't know if her visual problem was due to a manufacturing error from our grinding facility, or due to her doctor's prescription (which it probably is, at least in part).
She is a fairly high myope (-10 SD) and her prescription called for more minus in one eye, and less in the other. She couldn't recall if her doctor's office had neutralized her glasses during her appointment, which was her first office visit.
As I said in my previous post, The 1.74 Varilux lenses do not give a true reading of the distance prescription in the lensometer. Our grinding facility provides us with a printout of what they read (using an automatic lensometer - I hate those things!) but that was not at all what I saw when I neutralized them. This forces me into the position of accepting their analysis of the lenses, either because they thought the lenses were passable, or they can't really figure them out either. I have brought these issues up to the store owner, who deals with the grinding facility's staff, but I can't resolve them.

Here's another conundrum. If I send this customer back to the doctor for an Rx check, I can almost guarantee they will look at her glasses, and say, "What the. . ."
How should I deal with this?

I don't have a good grasp on why these lenses are designed this way, what this design accomplishes, and how the heck someone can see through the distance portion of the lens, which in this customer's case reads about a diopter and a half weaker than the prescription calls for. I need an optical guru here.

Hello?

[High_Abbe]

I say stick to what works. I dispense Adaptars all day long without a complaint, but then again I know how to take a proper seg hieght!

[sticklert]

My understanding that the reason you can't use a traditional lensometer is because the manual lensometer is calibrated for an index of 1.53 and when you go checking a lens with a refractive index of 1.74 you will not read it correctly. However, the lab has an Auto lensometer which can be adjusted for index of refraction checking the lenses correctly.

[hipoptical]

First of all: High Abbe, you rock- except for the adaptar part. At least use an Image since it is not made by the enemy. Secondly, why would any of you buy into the 1.74 thing, anyway? If you don't care if your patient can see, by all means go on and dispense them. I know that "they" are going to say that tests show there are no problems, but we know problems exist. Higher index lenses always bring about more issues due to the lack of clarity of the materials. When the lens does work, you should know that it is because "prescriptions" are 97% subjective and dependent upon the general health and well-being of the person at any given time. The eye will almost always adjust anyway, given enough time and trial. In my opinion, Trivex is the way to go if not using plastic, and contacts or surgery for the remainder. Anyone who cannot accept the thickness of Trivex should go to 1.0 CT glass, except that we live in America, where everyone is lawsuit-happy.
Here's the deal: use whatever lenses you want. Take proper measurements, make sure the lenses are made properly, adjust them properly, TEACH your wearer how to use the lenses, and don't buy into Essilor's propaganda anymore. A Navigator works when done right, and it's cheap, cheap, cheap!

[For-Life]

First of all: High Abbe, you rock- except for the adaptar part. At least use an Image since it is not made by the enemy. Secondly, why would any of you buy into the 1.74 thing, anyway? If you don't care if your patient can see, by all means go on and dispense them. I know that "they" are going to say that tests show there are no problems, but we know problems exist. Higher index lenses always bring about more issues due to the lack of clarity of the materials. When the lens does work, you should know that it is because "prescriptions" are 97% subjective and dependent upon the general health and well-being of the person at any given time. The eye will almost always adjust anyway, given enough time and trial. In my opinion, Trivex is the way to go if not using plastic, and contacts or surgery for the remainder. Anyone who cannot accept the thickness of Trivex should go to 1.0 CT glass, except that we live in America, where everyone is lawsuit-happy.
Here's the deal: use whatever lenses you want. Take proper measurements, make sure the lenses are made properly, adjust them properly, TEACH your wearer how to use the lenses, and don't buy into Essilor's propaganda anymore. A Navigator works when done right, and it's cheap, cheap, cheap!

I have worn cr-39, trivex, 1.56, poly, 1.6, 1.67 and cannot tell any difference in the optics. Same with my customers.

[hipoptical]

I have worn them all as well. Uncoated poly is awful (especially Gentex), 1.67 is OK, but not good, the others are fine. With A/R coat, all are suitable for the average Rx. For those like me (fairly high myope) there is still a difference, with Trivex and CR-39 being preferable. Different things affect people in different ways, I know. We just all need to be careful when buying the hype associated with things that are not truly better. For example: Hoya claims a 1.71 index, Seiko has a 1.67. One would assume that the Hoya lens is thinner but it is not. Why would I assume that 1.74 is better? Because Essilor says so? They claim that Gentex is a good product- I think it is THE worst. Hey, use whatever you want. Just remember that we are supposed to be in a service industry; the field of OPTICS, not fashion only.

[TheEyesHaveIt]

I'm loving this thread! I'm learning so much! Thank you to all of you for your input!

[jrctx]

This is getting good! Hipoptical is right on the money about Essilor's propaganda. I spent years working directly with essilor and know how that machine works - well oiled and deceitful. Anyone can print test and study results skewed in their way. Well, I guess it is the French way!

[spartus]

I have worn them all as well. Uncoated poly is awful (especially Gentex), 1.67 is OK, but not good, the others are fine. With A/R coat, all are suitable for the average Rx. For those like me (fairly high myope) there is still a difference, with Trivex and CR-39 being preferable. Different things affect people in different ways, I know. We just all need to be careful when buying the hype associated with things that are not truly better. For example: Hoya claims a 1.71 index, Seiko has a 1.67. One would assume that the Hoya lens is thinner but it is not. Why would I assume that 1.74 is better? Because Essilor says so? They claim that Gentex is a good product- I think it is THE worst. Hey, use whatever you want. Just remember that we are supposed to be in a service industry; the field of OPTICS, not fashion only.

About 1.74, I have dispensed exactly one pair to a patient. It was, in fact, a redo--same frame, same rx, everything was precisely the same. I asked the patient if he could tell any difference between the two, and he said it was, "Crisper." He switched back and forth a few times, and definitely felt the 1.74 was--his word--crisper.

Did I mention he was an engineer? Anyway.

Considering that I had a perfect set of lenses to compare, I took CT and ET measurements on both, and the 1.74 was just about exactly 10% thinner on the edge--CT was roughly equal, within .1 mm. I don't recall the exact measurements, but it was something like 7.4mm to 6.7 mm ET (Rx -11.50 -2.50) and 5.8mm to 5.3mm (Rx -9.00 -1.50). I'd share with you the axis, but I don't remember, I'm going off memory, and my calipers aren't digital anyway. I do remember it was 10% thinner, and an engineer was satisfied with the clarity.

They were still a mile thick, of course. I've never really been a Panamic fan, plus we don't get a great deal of high hyperope/myope patients that would see any improvement using 1.74, so I don't worry about it much. Use the best lens for the patient's needs and budget, and stop sweating who made it.

[AWTECH]

Spartus Said:

Considering that I had a perfect set of lenses to compare, I took CT and ET measurements on both, and the 1.74 was just about exactly 10% thinner on the edge--CT was roughly equal, within .1 mm.

I know you think this is an exact comparison but the thickness material comparison could be off by 10%, based on your own statement that the variation in center thickness was within 0.1mm, which is 10% of a 1mm center thickness lens. I don't know what the US limits are for the 1.74 material. With MR-10 if properly processed with the correct hard coating process you can keep the center thickness to 1.0mm. What was the lens design used on the 1.67 comparision lens. If these are different non spherical single vision lens designs the edge thickness could vary at the same refernce point on a lens.

[spartus]

Base curve was--and I'm going off memory here--about 2.00 OU, both pair. I don't remember measuring both, but they didn't look substantially different. And I know that means squat in the real world, but it's the best I've got.

CT was on the order of 1.5/1.6, and (oddly) 2.2/2.3 for the two pair of lenses. I did write all this down, and I think I posted more accurate numbers a few months back, but I haven't got any idea where it is today.

As far as CT limitations, knowing that 1.74's tensile strength isn't nearly that of 1.67, 1.5 or so is probably the limit, but that's purely a guess on my part.

[Robert Martellaro]

My understanding that the reason you can't use a traditional lensometer is because the manual lensometer is calibrated for an index of 1.53 and when you go checking a lens with a refractive index of 1.74 you will not read it correctly. However, the lab has an Auto lensometer which can be adjusted for index of refraction checking the lenses correctly.

Todd,

Lensometers will provide accurate readings for all ophthalmic lenses. They are calibrated with reference lenses (gauge master).

The lens clock is calibrated to read the curves on crown glass (index 1.52) and will be inaccurate on lenses with a higher or lower index of refraction.

A 1.74 index PAL can be read accurately with a lensometer if the target is centered. If it is not centered (with higher powers it may not even be visible!) use prisms or "prism rings" to get the target lined up with the reticle.

Regards,

[Lemon]

This is not a problem concerning use of the lensometer, and I don't really know how lens clocks entered into this, but if you look at my first two posts about this, it sums up my problem.
I am not putting this customer in CR39 Adaptors, by the way.
I have followed up since those posts by trying to contact my rep (on vaca) and trying to get someone from Essilor who can answer my questions. Still no progress.

[Lemon]

By the way, I am not a fan of the Panamics either, and a little bird told me that they will be pulled off the market, when the Varilux Physio takes hold. This isn't the problem here, though.

[hipoptical]

Use the best lens for the patient's needs and budget, and stop sweating who made it.

I agree that one should use the best lens for each patient, according to his/her needs. My point is that it is all too common for people to sell-out to using Varilux, when there are better (yes, better) alternatives in many cases. People should not buy into propanganda, but in my non-regulated state, there are far too many "Opticians" out there who do not understand optics. (Some of us say we have opticians because they couldn't remember if the cheese or lettuce goes on the taco first, so they had to become an "optician")
My experience has been that we caanot get 1.67 to catch on, or Trivex either. Both are better alternatives to 1.74, and the progressives available are great in these materials. Why 1.74? Because Exxon, I mean, Microsoft, I mean Essilor "says so"...??? No thanks.

[spartus]

The negative reaction in general to 1.74 has been, to me, very strange. It's a great choice for super high RXs, and pointless for virtually everyone else.

When you factor cost, PAL availability, abbe, and general suitability for most patients, 1.67 is the better material most of the time. Even in my -13.50 patient I mentioned above, the lens was all of .7mm thinner, which is to say not very much. I had a -11.00 patient a few months back who I talked out of 1.74 and into 1.67, and pointed her to a frame that would minimize edge thickness (41/24, she had a 65 PD, you get the idea) and got the glasses her taken care of that much quicker.

I think of 1.74 as similar to when Maui Jim introduced those glass drill-mount Flexons. It's a "look what we can do" product, not one with a great deal of real-world usability.

[hipoptical]

The negative reaction in general to 1.74 has been, to me, very strange. It's a great choice for super high RXs, and pointless for virtually everyone else.

When you factor cost, PAL availability, abbe, and general suitability for most patients, 1.67 is the better material most of the time. Even in my -13.50 patient I mentioned above, the lens was all of .7mm thinner, which is to say not very much. I had a -11.00 patient a few months back who I talked out of 1.74 and into 1.67...

Your comments here are confusing to me, unless you think that a -13.50 is not a "super high RX". I think your better point is that this is a "look at what we can do" item. I also think that just because a person CAN afford something, it doesn't mean they should. (I'll put a Trivex Image up against any other lens out there, and my patient WILL be HAPPY, and still have money left for a weekend vacation.
Anyway... what happened to the original inquiry? Are you still out there? If you are, my insignificant little piece of advice is to stop buying into the propaganda, and purchase good lenses for better prices. Your patient will thank you. AMD is better than Intel, Firefox is better than Explorer, and a host of lenses are better than Varilux. (BTW... Crizal isn't best, either. Just ask Colts Laboratories.)

[spartus]

Your comments here are confusing to me, unless you think that a -13.50 is not a "super high RX". I think your better point is that this is a "look at what we can do" item. I also think that just because a person CAN afford something, it doesn't mean they should. (I'll put a Trivex Image up against any other lens out there, and my patient WILL be HAPPY, and still have money left for a weekend vacation.
Anyway... what happened to the original inquiry? Are you still out there? If you are, my insignificant little piece of advice is to stop buying into the propaganda, and purchase good lenses for better prices. Your patient will thank you. AMD is better than Intel, Firefox is better than Explorer, and a host of lenses are better than Varilux. (BTW... Crizal isn't best, either. Just ask Colts Laboratories.)

My point about the -13.50 was that it was certainly a super high RX, but the benefit he got out of it was probably .1 gram lighter weight and negligibly thinner edges, which is to say very little. I initially brought the situation up because someone was complaining up the thread about the lower abbe, and my (very) incremental, non-scientific study shows that it's probably about equal to 1.67 in clarity. I stress "probably" and "about".

The way I feel about 1.74 is that I probably wouldn't consider it at all in an RX lower than a -12.00, unless there are some extenuating circumstances--like if the patient's an engineer. ;) Hyperopes... maybe a little sooner--+9.00 or +10.00, but I have, I think two patients with that much correction, and they both wear FTs. So hardly at all. It's a showpiece--and I can say that from the experience of owning those Maui Jims I mentioned, and I'm forever terrified of breaking them.

And I also have to say that Opera is a significantly better browser than Firefox.

[hipoptical]

Sounds like we probably agree, even if the communication isn't perfect. I'm not a showpiece-guy. (Except for the VW Bug lenses I made for a drill mount just to show what can be done...:o) I still wonder what happened to the person who started this thread. WHERE ARE YOU? Did we bore you with this discussion?

[spartus]

Sounds like we probably agree, even if the communication isn't perfect. I'm not a showpiece-guy. (Except for the VW Bug lenses I made for a drill mount just to show what can be done...:o) I still wonder what happened to the person who started this thread. WHERE ARE YOU? Did we bore you with this discussion?

I tend to take the long way around to make a point. It's there, it's just mixed in with whatever else I thought of getting there.

[Bobie]

Panamic is good for plus power and will be not good like Varilux Comfort in minus power.

In case that you have to going for 1.74 , please going for Nikon i-13 / 1.74 for value price or Rodenstock Multigressiv ILT 1.74 for the second best or Rodenstock Impression ILT 1.74 if you would like to have the best.

Nikon Presio i-13



More information about Nikon Presio i-13 : http://www.essilor.com.sg/Profession...kon/presio.htm

More information about Rodenstock Impression ILT : http://www.perret-optic.ch