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  1. #26
    sub specie aeternitatis Pete Hanlin's Avatar
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    Between the short focal length and the base out prism hyperopes experience when reading through a PAL (which also requires the eyes to converge further), there can be quite a bit of required convergence for a hyperope with a high ADD. In fact, for low vision patients with exceptionally high ADDs (say, +6.00 or so) you can order base out prism in just the segment to reduce the amount of convergence necessary. IIRC, the inset on some of our variable inset progressives can go from 1.1-4.1mm per eye.

    Point being, the higher the ADD the greater the convergence required to see through the ADD- so the inset needs to be greater. Even if the patient chooses to read at a further distance, they'll be reading somewhere along the umbilic of the progression (which takes a path from the fitting cross to the center of the reading area.
    Pete Hanlin, ABOM
    Vice President Professional Services
    Essilor of America

    http://linkedin.com/in/pete-hanlin-72a3a74

  2. #27
    One eye sees, the other feels OptiBoard Silver Supporter
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    Quote Originally Posted by Pete Hanlin View Post
    In fact, for low vision patients with exceptionally high ADDs (say, +6.00 or so) you can order base out prism in just the segment to reduce the amount of convergence necessary.
    I believe you meant to write base in prism.

    The clinical rule is to incorporate base in prism equal to the add power plus 2. For example, a +5.00 add would have 7 prism diopters base in per eye.

    ~~~~~~~~~~~~~~~~~~~~~~~~~~

    The formula for determining the near PD is:

    NPD = DPD - DPD/1 + W(1/s - f/1000)

    W is work distance in mm
    s is the stop distance (average 27mm)
    F is the focal power

    For example, (if stop distance equals 27mm) the near multiplier (x distance PD) for a work distance of 40cm is .937.

    35cm = .928
    30cm = .925
    25cm = .903
    20cm = .881

    Best regards,

    Robert Martellaro
    Science is a way of trying not to fool yourself. - Richard P. Feynman

    Experience is the hardest teacher. She gives the test before the lesson.



  3. #28
    Ghost in the OptiMachine Quince's Avatar
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    Quote Originally Posted by bretk0923 View Post
    From my experience with it, Varilux lenses should have a one-year non-adapt clause in which you can switch to any other lens available at your lab for no charge. Contact your Essilor rep about it if they give you guff.

    Sounds like your patient needs something hard-designed, if she is searching for a wider reading zone. The Physio W3+ is a much softer design, hence why she isn't adapting to a slower power buildup. We have encountered this issue with certain hyperopes as well, they don't actually use their intermediate Rx, and they love short corridor lenses. If you really have to use Essilor, try Comfort W2+ Short. Definity, from my experience has more emphasis on the intermediate zone, which may not necessarily be what you're looking for. Otherwise I'd agree with Auto III.
    +1

    If you can't get her back into Hoya, Auto III should do the trick.
    Have I told you today how much I hate poly?

  4. #29
    Compulsive Truthteller OptiBoard Gold Supporter Uncle Fester's Avatar
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    Quote Originally Posted by Pete Hanlin View Post
    Disclaimer- Essilor employee.

    I really think you've hit on the real issue (i.e., increased vertex distance). Also, a +1 to center pupil placement. I know some PALs work better with a modified fit, but Varilux lenses really perform their best at pupil center. Not saying Varilux Physio W3+ is a perfect solution for every patient- and it may not be the best solution for this particular patient at the end of the day- but there are a lot of hyperopes happily wearing that design (as stated, each person's visual system is unique- which is why it's a good thing we have 100s of PALs to choose from). Hoping you find a good solution for this patient- regardless of which design provides the answer.

    Not to get too far off the topic of the original post, but regarding contour plots I really REALLY wish you could determine how a lens will perform based on it's plot (because it would save me a TON of money in wearer studies). Unfortunately, experience shows that contour plots are virtually useless in telling me how a PAL will perform in real life (probably because they only contain information on cylinder and sphere levels without showing the axis of the cyl or the balance of corresponding points).

    That's easy to say, but let me give some examples. First, a couple of contour plots Darryl gave me years ago. The lens on the left has an obviously narrower intermediate and a LOT more unwanted astigmatism than the lens on the right. So, according to the plots, the lens on the right should be far superior...
    Attachment 13388
    The lens on the left is SOLA VIP (which- for its age- is still a decent PAL, I have a pair myself). The lens on the right is SOLA XL, which was originally supposed to replace VIP and later was positioned as a complimentary lens to VIP. VIP has always been FAR more popular and quite a few of them are still sold today. The add power is the same? I thought each plot represented a certain amount of astigmatism and any lens with the same add power had the same number of shaded color plots but in different places according to Minkowitz. No?

    Using a more modern example, here are two Plano +2.00 plots I made a few years ago prior to a wearer study (the lens on the right is a non-Varilux Essilor design and the lens on the left is a competitive design). When I made the plots, I thought "We are going to absolutely KILL this lens for distance width!" In real life, however, there was no statistically significant difference in perceived width (in fact, the competitor lens on the left was preferred by one more person in an n=33 study than the lens on the right for distance width, which still left us with a p=1.000, or "no difference"). In fact, there was only ONE statistically significant difference in the perceived performance of these two lenses (the lens on the right was significantly better for transitioning between distance, near, and intermediate).
    Attachment 13389

    Point being, although it seems logical you could predict performance from contour plots, you really can't (at least I can't, and I can create some pretty cool plots :^). I've seen this in study after study. Here's why (at least IMO)... Spherical width and max level of astigmatism are NOT the most crucial aspects of a PALs design- but that's all a contour plot will show you. It makes sense if you think about it, a FT28 has 26mm or so of spherical width and virtually no unwanted astigmatism- yet most studies have shown people prefer the functional vision provided by PALs (even though a PAL has significantly less spherical width). Will Hasbro (or whoever has the patent) let me license my Optiboard famous "MAGIC PROGRESSIVE 8 BALL? Just shake and turn it over it to determine your progressive!

    Progression rate, binocular balance, and prismatic effects all have a profound effect on wearer perception, and none of them are shown by a contour plot. Here's a plot of binocular balance comparing the binocular fields of two generations of Varilux progressive designs (think 14-20 years ago, one of the products isn't even available anymore). The lens on the right provides far superior binocular balance- which is why patients were much more comfortable in this lens (IF it was fit accurately). However, these two designs look very similar on a contour plot (in fact, I remember going back and forth with one educator who plotted the lenses and claimed there was "no difference" between the two). These plots were included in the original education on the new design, but were later abandoned because it was too difficult for most opticians to understand their significance.
    Attachment 13390

    Oh, and yes we still sell DEFINITY (currently DEFINITY 3 :^). Any chance you can provide the plot pictures? Call me a doubting Thomas, and no offense Pete - But you are with the Big E. Who's marketers are the optical world's best if you excuse my backhanded compliment.
    In all seriousness thanks for the post!

    Never the less I still would like the pictures as I was known to show them to patients I was changing and they accepted the new improved lens based on what they saw in the pictures. Like you say- Perception is everything!!!

    Apologies to Kaypaula for the semi hi jack...

  5. #30
    One eye sees, the other feels OptiBoard Silver Supporter
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    Quote Originally Posted by Uncle Fester View Post
    Will Hasbro (or whoever has the patent) let me license my Optiboard famous "MAGIC PROGRESSIVE 8 BALL? Just shake and turn it over it to determine your progressive!
    ● It is certain
    ● It is decidedly so
    ● Without a doubt
    ● Yes definitely
    ● You may rely on it
    ● As I see it, yes
    ● Most likely
    ● Outlook good
    ● Yes
    ● Signs point to yes
    ● Reply hazy try again
    ● Ask again later
    ● Better not tell you now
    ● Cannot predict now
    ● Concentrate and ask again
    ● Don't count on it
    ● My reply is no
    ● My sources say no
    ● Outlook not so good
    ● Very doubtful
    Science is a way of trying not to fool yourself. - Richard P. Feynman

    Experience is the hardest teacher. She gives the test before the lesson.



  6. #31
    Compulsive Truthteller OptiBoard Gold Supporter Uncle Fester's Avatar
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    Quote Originally Posted by Robert Martellaro View Post
    ● It is certain Multiple pairs single vision
    ● It is decidedly so Same design
    ● Without a doubt POW compensated
    ● Yes definitely Essilor Definity
    ● You may rely on it Comfort
    ● As I see it, yes Zeiss Individual
    ● Most likely Shamir Autograph 3
    ● Outlook good Seiko Supernal
    ● Yes FT-28
    ● Signs point to yes In Touch
    ● Reply hazy try again Hoya Amplitude mini
    ● Ask again later Younger image
    ● Better not tell you now Cost of POW Compensated
    ● Cannot predict now Shamir Workspace
    ● Concentrate and ask again Essilor VIP
    ● Don't count on it Nalco Progressive
    ● My reply is no Essilor Panamic
    ● My sources say no Creation
    ● Outlook not so good Natural
    ● Very doubtful Unity

  7. #32
    One eye sees, the other feels OptiBoard Silver Supporter
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    Quote Originally Posted by Uncle Fester View Post
    Perfect.

    Check your PM folder.
    Science is a way of trying not to fool yourself. - Richard P. Feynman

    Experience is the hardest teacher. She gives the test before the lesson.



  8. #33
    sub specie aeternitatis Pete Hanlin's Avatar
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    Quote Originally Posted by Robert Martellaro View Post
    I believe you meant to write base in prism.
    Ugh, yes- base IN prism (displaces the image outward to relieve convergence requirement).

    Thanks for the correction!
    Pete Hanlin, ABOM
    Vice President Professional Services
    Essilor of America

    http://linkedin.com/in/pete-hanlin-72a3a74

  9. #34
    Master OptiBoarder LENNY's Avatar
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    Quote Originally Posted by Pete Hanlin View Post
    Actually, any good modern PAL design will be different for various levels of ametropia due to multi-design (actually, numerous traditional PALs are multi-design as well... I think we forget a traditional lens has 144 individual skus, so they are quite capable of being pretty darn "custom"). For example, in a single design the rate of progression should be different for a hyperope vs. a myope due to prismatic effects (a myope is fortunate to be reading through base down prism- which displaces the near image upwards, a hyperope is reading through base up prism, which moves the image downwards). Ditto for near inset- the larger the ADD power and/or the higher the distance plus power, the greater the inset will need to be due to prismatic effects. Likewise, the level of presbyopia should be accounted for by variation of the base design. The near zone of a +3.00 ADD has a focal length of 33cm, which requires more inset than a +1.00 ADD, and higher levels of ADD require a distribution with more power at the top of the progression.
    I hope you are saying this about Free Form progressives... Most of the progressive SF have a limited number of base curves blanks so not many variations...

  10. #35
    sub specie aeternitatis Pete Hanlin's Avatar
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    Quote Originally Posted by LENNY View Post
    I hope you are saying this about Free Form progressives... Most of the progressive SF have a limited number of base curves blanks so not many variations...
    I refer to both modern digital and traditional progressives. A traditional progressive lens can have up to 72 distinct designs (6 base curves x 12 ADD powers), since each base curve / ADD combination is made with a unique mold. This allows for a pretty robust range of insets, progression distributions, and other variations which ensure optimal performance for different levels of ametropia and presbyopia. For example, an 8B +3.00ADD blank can have a design that is quite different from a 2B +1.00ADD blank (i.e., the inset may vary by 3mm across the range, and the progression weighting can also vary greatly).

    Zeiss GT2 progressive lenses (traditional) are an excellent example (as are traditional Varilux Physio progressive lenses). These designs both feature a robust multi-design approach that provides different design profiles for hyperopes vs. myopes, and for those with high ADD vs. low ADDs.

    When you convert these designs to FBS (full back surface- digital- aka "freeform"), the multi-design will be more finely tuned, but the effects on the final performance perceived by the wearer isn't going to be dramatic. Both of these products are available as FBS designs, BTW. Consider a sport jacket with 72 variations of size (chest size, arm length, trunk length, etc.). The VAST majority of people would be able to find a jacket that fits VERY well with that level of variation (sport jackets don't have that many available variations, btw). Yes, it's possible a tailor might be able to further fit the jacket, but the overall style and quality of the jacket is going to be FAR more important than the incremental improvements made by the tailor.

    Without question, digital surfacing does provide the designer with the potential to customize the design beyond the capabilities permitted by the traditional surfacing process, but the level of final performance is going to FAR more influenced by the quality of the design itself vs. the manner in which it was processed. Both Zeiss GT2 traditional (or Varilux Physio traditional) progressive lenses are going to provide far superior performance than many of the FBS designs available on the market (there are wearer studies that prove this).

    Sorry for the ramble, but- during market research with Optometrists and Opticians- I often hear "Well, if it's digital it must be good" (which is completely, utterly incorrect). As an employee (and stock holder) of a manufacturer who produces a LOT of digital progressive lenses, I very much appreciate the capabilities digital provides. I'm wearing Varilux X Series lenses as I type, and there's absolutely no way a traditional lens could provide the visual benefits of this lens (then again, neither could an FBS lens). I would much prefer practitioners to recommend and dispense our digital products, but it is important to maintain perspective on the realities of digital vs. traditional surfacing. The idea that digital lenses are always better is similar to saying all Blu-Ray movies are better than those on standard DVDs (or even, gasp VHS). I'd much rather watch Goldfinger on VHS than Waterworld on Blu-Ray!
    Pete Hanlin, ABOM
    Vice President Professional Services
    Essilor of America

    http://linkedin.com/in/pete-hanlin-72a3a74

  11. #36
    Eyes eastward... Uilleann's Avatar
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    Yeah Pete, but what about Gigli in 4K & 3D???? THAT has got to be a spectacle to behold! Probably even better than the new V X series lenses!

  12. #37
    Master OptiBoarder OptiBoard Gold Supporter
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    Quote Originally Posted by Pete Hanlin View Post
    The idea that digital lenses are always better is similar to saying all Blu-Ray movies are better than those on standard DVDs (or even, gasp VHS). I'd much rather watch Goldfinger on VHS than Waterworld on Blu-Ray!
    This distills so much nonsense that is out there into such a simple concept I'm going to use it.

  13. #38
    Master OptiBoarder OptiBoard Silver Supporter lensmanmd's Avatar
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    Quote Originally Posted by Tallboy View Post
    This distills so much nonsense that is out there into such a simple concept I'm going to use it.
    The variables available with digital worries me. Like any tool in the wrong hands renders it useless. A screwdriver to hammer nails as an example. When POW is not properly measured, it will make the best of Freeform designs perform worse than molded. I wish that more opticians trust average fit for freeforms, rather than forcing POW. All of today's calc engines work wonders.

  14. #39
    Master OptiBoarder OptiBoard Gold Supporter
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    Quote Originally Posted by lensmanmd View Post
    The variables available with digital worries me. Like any tool in the wrong hands renders it useless. A screwdriver to hammer nails as an example. When POW is not properly measured, it will make the best of Freeform designs perform worse than molded. I wish that more opticians trust average fit for freeforms, rather than forcing POW. All of today's calc engines work wonders.
    Absolutely. Not to mention what good are POW measurements if they are going to be a FAR cry from the POW of the frame after it is finished? Also from a dispenser/finishing lab's perspective - the variables involved in surfacing involve a TON of trust in your surfacing lab. I can trouble shoot a DVO RX being off, but tolerances of progressive optics? I can't raytrace lenses here. Its one thing when they were being tracked by a lens manufacturer during a molding process, but if bobby joe wants to push his yield out when things are teetering to the edge of acceptable because machines need to be calibrated etc, there is absolutely no way for me to trouble shoot that.

    Also don't forget you are using IOT stuff, which is cutting edge tech - even in their "basic" designs. There are a TON of digital lenses dispensed here in my town that can't sniff IOT's jock.

  15. #40
    sub specie aeternitatis Pete Hanlin's Avatar
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    Quote Originally Posted by Uilleann View Post
    Yeah Pete, but what about Gigli in 4K & 3D???? THAT has got to be a spectacle to behold! Probably even better than the new V X series lenses!
    Oh, I am soooooooo mad at you! I actually looked up Gigli on IMDb to read the plot... Once you read something like that, you can't just unread it! I sentence you to watch Spice World (1997, featuring the Spice Girls)! Hmmm, could you imagine the "director's cut" version of that movie "At one point, Victoria Beckham accidentally locked herself inside her car... it took 3 hours to rescue her."
    Pete Hanlin, ABOM
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  16. #41
    Master OptiBoarder OptiBoard Silver Supporter lensmanmd's Avatar
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    Gigli or Snakes on a Plane....your call.

  17. #42
    Master OptiBoarder OptiBoard Silver Supporter lensmanmd's Avatar
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    Quote Originally Posted by Tallboy View Post
    Also don't forget you are using IOT stuff, which is cutting edge tech - even in their "basic" designs. There are a TON of digital lenses dispensed here in my town that can't sniff IOT's jock.
    LOL...your town is basically my town!

    IOT and Zeiss FF are our bread and butter. IOT is like BASF. We don't make the products that you use, we make them better! Too bad that more opticians don't appreciate IOT, but again, every lab that produces IOT rebrands them, unlike other branded FF. Even our Zeiss OEM is branded as ours.

    That said, I just received a trial pair of the Zeiss Energize Me. I am thoroughly impressed with it. I'm thinking of adding it to our line.

  18. #43
    OptiBoard Apprentice Miss Peepers's Avatar
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    error error-- sorry can't figure out how to delete this
    Last edited by Miss Peepers; 08-01-2017 at 11:53 AM.
    Have a great day!

  19. #44
    What's up? drk's Avatar
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    I like contour plots.

    Sure, ray tracing diagrams would be better, but that's not happening.

    AT LEAST the companies could DESCRIBE the shape of the design (a la Sharpstick) and/or the INTENTION of the design.

    The reason, IMHO, that the predictive value of such information is not 1.0 is because of the plenitude of variables.

    But it's information, and we need information.

  20. #45
    One eye sees, the other feels OptiBoard Silver Supporter
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    Quote Originally Posted by drk View Post
    I like contour plots.

    Sure, ray tracing diagrams would be better, but that's not happening.

    AT LEAST the companies could DESCRIBE the shape of the design (a la Sharpstick) and/or the INTENTION of the design.
    Zeiss and IOT offer lens design biases, that is, distance, intermediate, near, and corridor length, although the latter is not always defined in a way that is particularly useful.

    From what I've read, and experienced after many personal blind trials, differences in intermediate and near zone width are difficult to discern from the wearers viewpoint, but corridor length can make or break a design, especially for absolute presbyopes.

    The reason, IMHO, that the predictive value of such information is not 1.0 is because of the plenitude of variables.

    But it's information, and we need information.
    Wearing/auditioning the lens design works for me, with a few surprises.

    Best regards,

    Robert Martellaro
    Science is a way of trying not to fool yourself. - Richard P. Feynman

    Experience is the hardest teacher. She gives the test before the lesson.



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