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  1. #1
    What's up? drk's Avatar
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    X, Y, and Z

    OK, essilor reps seen today. There has been, I've noted, a foray into "depth of focus" a lot, lately.

    For context, we've had EDOF ("extended depth of focus") technology FOREVER, but we've been calling it aspheric multifocal contacts. Unilens, Conforma and David Volk started it before my time, and B&L bought it (I think that's right). Essentially it's a "low asphericity" conical section multifocal and they use the daylights out of it in RGPs and SCLs, now.

    THEN the big hot thing was to incorporate it into IOLs, and after decades, ophthalmology is touting how great EDOF is. (Yawn. But correct.)

    SO NOW recently it seems that the lens companies are figuring out ways to make such asphericity part of the lens design. I don't understand--because of marketing mumbo-jumbo because apparently the reps are too stupid and we're too stupid to be talked to any other way--but it seems that some/all points within the corridor and near zone have extended depth of focus (due to this asphericity, I think). The benefit touted is that the patient has more play in depth of focus at a given head angle/lens location and won't feel such a need to look up and down the corridor.

    The way I think of it, is that while Varilux has done quite a yeoman's job of smoothing out peripheral astigmatism in the X and Y coordinates (that is, on the lens surface) now they're smoothing in the Z axis, back-and-forth or "in-and-out".

    Question 1: Anyone have insight on this?
    Q2: Am I getting this right?
    Q3: Does this work?
    Q4: What would we give up? I'm thinking "soft focus = low contrast or less clear".

    I'm pretty sure I've heard of this approach from Zeiss or Shamir, too?
    Last edited by drk; 01-19-2023 at 03:52 PM.

  2. #2
    Compulsive Truthteller OptiBoard Gold Supporter Uncle Fester's Avatar
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    Will Pete Hanlin risk the lions den?

    Haven't heard from him in a while.

  3. #3
    What's up? drk's Avatar
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    His name was brought up by the field rep...

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  4. #4
    What's up? drk's Avatar
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  5. #5
    What's up? drk's Avatar
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    Evaluating lens performance using “volume of acuity”


    « Researchers introduced a new concept: the “volume of acuity” needed for comfortable vision. That refers to the volume of space that a wearer can perceive through the lens with the necessary visual acuity to perform typical tasks at each distance. »
    To evaluate the performance of the Varilux® X seriesTM progressive lens, researchers introduced a new concept: the “volume of acuity” needed for comfortable vision. That refers to the volume of space that a wearer can perceive through the lens with the necessary visual acuity to perform typical tasks at each distance: reading with near vision, looking at a computer screen with arm’s-length vision, deciphering text with intermediate vision, etc. That volume, which had only rarely been identified in the past, indicates the wearer’s three-dimensional area of clear vision, with specific attention to the depth of the wearer’s field of vision.Thus, if we compare the volume of acuity obtained with the Varilux® X seriesTM lens with that of an earlier progressive lens, we see (as shown in Figure 6) that the volume of vision is considerably enlarged both in width and depth, especially in the area of so-called arm’s- length vision. The XtendTM technology makes it possible to maintain visual acuity at a higher level than the threshold previously defined (0.15 Log MAR at 70 cm), with the result that wearers enjoy a significantly larger area of clear vision.



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  7. #7
    What's up? drk's Avatar
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    I read that "paper" carefully. It's crap. It's mumbo-jumbo.

    As far as I can tell, they perhaps made the lens a little more "V-shaped" (meaning they widened the intermediate zone) and probably they changed the rate of progression through the corridor to make the intermediate more useable on a desktop (but we know that's quixotic).

    What I was interested in was this "Extend technology" and it barely discusses it.

  8. #8
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    I've heard similar things about Varilux X in particular. Despite my effort, I have also been unable to get any straight answers on how this actually works, not for lack of trying.

    I've dispensed many many Varilux X jobs and although it's hard to say with any certainty, my inclination is that this Extend Technology probably doesn't amount to much. Would love to hear about this from somebody who's in the know though!

  9. #9
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    Quote Originally Posted by drk View Post
    OK, essilor reps seen today.
    You must be the lens rep's worst nightmare LOL. You should just ask to have Pete Hanlin call you at your office ^_^

    Curious to hear the answers to your questions as well.

  10. #10
    What's up? drk's Avatar
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    They're very nice but Essilor is pehaps the worst at marketing-speak that means absolutely nothing. They try to dazzle you and you're supposed to say "OK, I guess. I'm an essilor Expert, now."

    It's sad the industry doesn't respect/encourage/educate their REAL customers: optical people. They seem to have a low opinion of us, like we're consumers. Save the jazz for the consumers.

  11. #11
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    Quote Originally Posted by drk View Post
    They're very nice but Essilor is pehaps the worst at marketing-speak that means absolutely nothing. They try to dazzle you and you're supposed to say "OK, I guess. I'm an essilor Expert, now."

    It's sad the industry doesn't respect/encourage/educate their REAL customers: optical people. They seem to have a low opinion of us, like we're consumers. Save the jazz for the consumers.
    Most of the reps I have seen for lens companies aren't former opticians but sales people. They don't understand the lenses well enough from a technical standpoint to tell us anything more than the marketing mumbo jumbo. This lens has wavefront technology... cool. What is that and how is it different from what Zeiss/Hoya/Shamir offer? This lens has path optimization! Okay, but really any lens with a baby add power will be optimized right? So how is this lens different from an older generation progressive with a small add? They just look at me with a blank face.

  12. #12
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    Quote Originally Posted by naicitpo View Post
    most of the reps i have seen for lens companies aren't former opticians but sales people. They don't understand the lenses well enough from a technical standpoint to tell us anything more than the marketing mumbo jumbo. This lens has wavefront technology... Cool. What is that and how is it different from what zeiss/hoya/shamir offer? This lens has path optimization! Okay, but really any lens with a baby add power will be optimized right? So how is this lens different from an older generation progressive with a small add? They just look at me with a blank face.
    bingo!!!!

  13. #13
    What's up? drk's Avatar
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    I read the Varilux XR white paper, again. It's so full of crap. It's almost a parody. It's like the "Mentos the Freshmaker" commercial.



    However they do it (and I think it's because they are using some point-by-point asphericity if that's even possible) it sounds to me like a super-soft single-vision-like design with "soft focus" (kind of like the old Japanese "fuzzy logic" of days of yore).

    I'm trying it on an outside ophthalmology Rx where the patient has a +2.50 add and never wore PALs before. Should be a good test.

  14. #14
    What's up? drk's Avatar
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    The Europeans don't know how to market worth crap.

  15. #15
    What's up? drk's Avatar
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    I can't find the original thread but we put an outside ophthalmology Rx 59 y.o. patient into her first PAL and we opted for Varilux XR.

    OD +0.25 +1.00 x 060
    OS +0.25 +0.50 x 105
    +2.50 add

    Not too heavy of a lift in the distance zone, but some oblique astigmatism, there.

    My thinking was that this XR should be "uber soft" based on my perception of what their concept is (and all I get is a perception).

    One week after dispense she's happy with them, so there's that.



    I have no idea what the lens does, but I'm under the impression that, you know...the honey comb "pixel" concept whereby they may take a small lens area and make it an aspheric lenslet with an increased depth of focus...could allow them to minimize the steepness of the walls of unwanted astigmatism increase alongside the corridor and near zone, and probably distribute some of it into the distance zone, and make a super low-swim design (at the cost of high contrast) that would be a great way to get a noob into a full add PAL.

    Maybe it's going to work.
    Maybe I just made all that up.

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  17. #17
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    Couldn't they come up a better marketing term than that?? Sounds more like ED product tech

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    Quote Originally Posted by drk View Post
    Evaluating lens performance using “volume of acuity”


    « Researchers introduced a new concept: the “volume of acuity” needed for comfortable vision. That refers to the volume of space that a wearer can perceive through the lens with the necessary visual acuity to perform typical tasks at each distance. »
    To evaluate the performance of the Varilux® X seriesTM progressive lens, researchers introduced a new concept: the “volume of acuity” needed for comfortable vision. That refers to the volume of space that a wearer can perceive through the lens with the necessary visual acuity to perform typical tasks at each distance: reading with near vision, looking at a computer screen with arm’s-length vision, deciphering text with intermediate vision, etc. That volume, which had only rarely been identified in the past, indicates the wearer’s three-dimensional area of clear vision, with specific attention to the depth of the wearer’s field of vision.Thus, if we compare the volume of acuity obtained with the Varilux® X seriesTM lens with that of an earlier progressive lens, we see (as shown in Figure 6) that the volume of vision is considerably enlarged both in width and depth, especially in the area of so-called arm’s- length vision. The XtendTM technology makes it possible to maintain visual acuity at a higher level than the threshold previously defined (0.15 Log MAR at 70 cm), with the result that wearers enjoy a significantly larger area of clear vision.



    We used to call that 20/Happy. Barry Santini, you out there?

  19. #19
    Master OptiBoarder OptiBoard Silver Supporter Barry Santini's Avatar
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    Quote Originally Posted by wmcdonald View Post
    We used to call that 20/Happy. Barry Santini, you out there?
    Yup!

  20. #20
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    Late to the game as always but as an optometrist who has happily dispensed many pairs of Varilux S (2015 - 2018) and X (2018 - present), with mostly good results, here's my observations on these two designs... just my personal opinion and understanding of the designs, not necessarily the gospel truth.

    TLDR: not the easiest designs to dispense, very reliant on 1) fitting, 2) managing wearer expectations.

    Explanations as follows, I've tried to keep it brief :)

    Disclaimer: I do not work for Essilor, I'm lucky enough to have worked for employers who don't limit what I dispense, and I believe I've had solid lens reps over the decade or so I've been dispensing.

    ---

    Varilux S

    Worthwhile to revisit the logic of the S-series, since as I understand it, the X-series mainly adds Xtend function to the basic S design.

    S design, as I know it, focuses on reducing swim effect via a design feature named Nanoptix. Works by placing all the progressive optics on the back surface of the lens, while the front is steeper convex at the distance portion, becoming slightly less convex moving downwards (think the reverse of a Camber blank as best I could figure out). The logic being that flattening the lens towards the bottom reduces magnification moving down the corridor, thereby reducing swim.

    While this 'reversed geometry' design might reduce swim as such, this may also cause a 'softening' of the near vision somewhat, especially in hyperopes who might notice the difference in clarity through a flatter near zone.

    Once I'd wrapped my (significantly alcohol-pickled and hyperactive) mind around these points gleaned from various reps, I decided to only dispense Varilux S to:
    - Patients whose concern was more to comfort of a progressive than crystal clarity
    - Following from that, hyperopes (who I reasoned, would notice more benefits from a flatter lens than myopes)
    - Since it's a dual-surface design in some way, I deduced that it would be extra sensitive to position of wear, and so used the S Fit for cases where the fitting deviated from the POW values provided by my Essilor rep

    And for the most part, it was good years with the S-series using those personal rules of thumb.

    ---

    Varilux X

    So along came this souped up design with Xtend technology.

    As I understand it, Xtend makes only a portion of the corridor behave similar to a multifocal contact lens. Can't recall the exact figures, but I was told by my then rep that the Xtend function is restricted to just between the midpoint of the corridor and just above the near circle. So, basically the lower half of what we'd consider intermediate distance.

    It was further explained to me that unlike traditional progressive optics, where as you move down the corridor, the add increases, this Xtend zone (for lack of a better term) was designed and surfaced such that the upper half of the zone could provide functional vision at intermediate range normally only viewable through the bottom half of the Xtend zone. And vice-versa for the bottom half of the zone, which could provide functional vision corresponding to an intermediate range normally only viewable through the upper half. Therefore providing a wider depth of focus for intermediate viewing tasks, only when using this Xtend zone.

    With regards to the term Volume of Acuity, this then made sense to me, since traditionally we consider progressive lens designs in terms of how wide the clear zones are (a 2-dimensional measure), but the X-series allegedly intended to enhance front/back range of clear vision (expanding range of clear vision along a third axis closer and further from the wearer, making it 3-dimensional measure of volume of space which can be perceived clearly). So far, so good for me.

    My thoughts on this, from 2018 - present:
    - If true, Xtend function only needs to cover a portion of the addition, instead of the full addition as per a multifocal CL, so the surfacing might be less complex than expected.
    - While multifocal CL often have softening of vision clarity, the Nanoptix base design already has that anyway, so perhaps it masks the potential drawbacks of Xtend.

    From there, I kept dispensing only to patients I'd normally use the S-series for, and frankly, I did not sell it for the Xtend function at all. The price difference from the S-series wasn't a huge jump then anyway.

    Anecdotal feedback from patients indicates that switching out from X-series into other designs felt like they had to exert more downgaze and/or neck movements to achieve certain intermediate tasks (viewing GPS when driving, or the upper half of a page of text being in focus with what felt like less eye movements with the X lens, and most notably reading in bed), which aligns with the claims made of the Xtend technology to me.

    Also, I have had more of the above feedback from those wearing the lenses such that the Xtend zone was more readily accesible (short corridors, or frame fittings that kept the lower half of the lens nicely within reach). Which to me verifies the rep's claim that the Xtend zone is limited to the lower portion of the lens.

    And lastly, mirroring my earlier experience with S Fit, the X Fit performs noticeably more consistent for position of wear deviating from the standard X design.

    ---

    So... that's just my experience using the Varilux X family of lenses. It's been mostly positive and profitable over the last 5 years or so, and frankly I've not had adequately bad experience with these lenses to stop using them. Maybe my reps successfully sold me snake oil, maybe my patients are easy to please, and maybe I'm just a lucky guy the optical gods chose not to give many non-adapts. But I've had a good time with the S and X series so far, and Essilor/Nikon products in general.

    Your mileage may vary, though :)

  21. #21
    What's up? drk's Avatar
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    Great feedback!

  22. #22
    What's up? drk's Avatar
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    OK, a year later I saw (a new) essilor rep. Very nice, straightforward and pretty knowledgeable.

    To re-hash:
    The WAVE technology is old stuff (wavefront-inspired I think, from LASIK) where essentially the digital surfacing and the mathematics reduce higher-order aberrations. Whatever. Can't hurt.

    The Nanoptix technology (represented by the beehive thingy) is more along the lines of flattening the inferior-temporal curvature of the PAL in order to reduce swim/extend the focal point (reminds me of the Definity design goal).

    The X stuff has the "extend technology" which is fascinating to me, and Andy thinks it's in the lower corridor to improve depth of focus and eliminate excessive head tilting as you search for the clear zone on an intermediate task.

    Also, and it's improved in the XR, is the design goal of reducing left lens/right lens disparities in power, which doesn't always apply but is nice in cases of unequal powers. (We used to have that "design by pair" technology before, but I think it applied to something limited like near zone width. I think this is a more global lens approach.)

    Bottom line for me, to dumb it WAY down, is that essilor continues to value single-vision-like design goals, so that their lens is comfortable to wear. If I'm not mistaken, the converse design goal of particularly "crisp/high contrast" vision would be lacking.
    Last edited by drk; 01-03-2024 at 02:27 PM.

  23. #23
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    So, with a pleasant year end (belated Merry Christmas and a Happy New Year to all) behind me, and the dust settling from the usual colourful state of affairs called annual close of business... :)

    I went digging for the old Varilux X white paper, as I thought I'd find the relevant information there. And find it I did :D

    White paper available here:
    https://info.icarelabs.com/hubfs/Var...te%20Paper.pdf

    And to help those who maybe are slower readers or who lack the time and/or inclination to go through the entire document, attached are clippings from the white paper showing how Essilor emphasises what they define as vision within arm's reach, the specific portion of the addition range attributed to that arm's reach vision, and also a progressive lens map showing where it is (which I believe is somewhere about the lower half of the corridor due to the addition range specified, regardless of actual corridor length).

    TLDR: Xtend focuses on the part of the corridor corresponding to 60-85% of the wearer's prescribed addition (expected to improve depth of field and reduce necessary eye movements for working distances ranging from 16-28 inches).

    Click image for larger version. 

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    Last edited by AndyOptom; 01-04-2024 at 07:22 PM.

  24. #24
    What's up? drk's Avatar
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    Nice.

  25. #25
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    Make an offer...I can be bought!!!

    Quote Originally Posted by drk View Post
    OK, essilor reps seen today. There has been, I've noted, a foray into "depth of focus" a lot, lately.
    I'm going to trade mark "Conceptual Perception" Monday!

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