Page 2 of 4 FirstFirst 1234 LastLast
Results 26 to 50 of 76

Thread: What Lens are truly Freeform?

  1. #26
    Banned
    Join Date
    Feb 2012
    Location
    Golden State
    Occupation
    Dispensing Optician
    Posts
    340
    True and False.... Lenscrafters and Walmart uses discontinued Shamir lenses which means your patient cannot get the latest technology lens they offer from them
    .
    Quote Originally Posted by EyeMaster View Post
    Ya... but Shamir is also available at Lenscrafters and Walmart and most of the other chains

    If Walmart has it I don't need it....

  2. #27
    Master OptiBoarder OptiBoard Silver Supporter
    Join Date
    Jun 2008
    Location
    Seattle WA
    Occupation
    Optical Wholesale Lab (other positions)
    Posts
    2,841
    Quote Originally Posted by GokhanSF View Post
    Essilor doesn't have a true freeform yet, so consider Shamir AutoII, Hoya ID, Zeiss Individual, and Kodak Unique.
    Physio DRx and Physio Enhanced Fit are both 100% Free-form.
    Beer is proof that God loves us and wants us to be happy ~Benjamin Franklin

  3. #28
    Banned
    Join Date
    Feb 2012
    Location
    Golden State
    Occupation
    Dispensing Optician
    Posts
    340
    I don't think they are 100% freeform. Just because freeform surfacing is used doesn't mean you get a freeform lens. You also need a lens blank and design. :)
    Quote Originally Posted by sharpstick777 View Post
    Physio DRx and Physio Enhanced Fit are both 100% Free-form.

  4. #29
    OptiBoard Professional
    Join Date
    Nov 2007
    Location
    Ft Lauderdale, Florida
    Occupation
    Other Optical Manufacturer or Vendor
    Posts
    147
    Quote Originally Posted by GokhanSF View Post
    Essilor doesn't have a true freeform yet, so consider Shamir AutoII, Hoya ID, Zeiss Individual, and Kodak Unique.
    And dont forget IOT designs (shameless plug)

  5. #30
    Banned
    Join Date
    Feb 2012
    Location
    Golden State
    Occupation
    Dispensing Optician
    Posts
    340
    :) Of course IOT designs are freeform... Kurt can you please clarify what true freefom is? As far as I know Physio DRx and Physio Enhanced are not true freefom.
    Quote Originally Posted by hyperoptic View Post
    And dont forget IOT designs (shameless plug)

  6. #31
    OptiBoard Professional
    Join Date
    Nov 2007
    Location
    Ft Lauderdale, Florida
    Occupation
    Other Optical Manufacturer or Vendor
    Posts
    147
    Quote Originally Posted by sharpstick777 View Post
    Kurt, could you please clarify what you define as "compensated"? There is some word in the market that only Free-form lenses that offer "customized" vertex, face form and panto calculations are truly better. However, I have seen usage studies from both manufacturers and universities where only about 11% of patients benefit from those advanced compensations (Essilors says 9%).

    All true-free form are compenstated with at atoric, base curve, ect, and most use standard averages of tilt and vertex. So when you say "compenstated" are refering to the standard ones, or the fully customized ones?

    And if you mean that only the highly customized compensated lenses are better, do you have any usage studies your company has done (or at least read) to support that? Right now the ones I have seen do not.
    By compensated I am referring to ether using an average value, or individual measurments to compensate for, at least in the case of IOT Digital Ray Path technology the oblique aberration experienced by a wearer, our non compensated designs do not take these values into consideration when calculating the back surface of a lens thus providing a digitally surfaced progressive that supplies prescribed power, not compensated power.

    As far as the effect of compensation by percentage, to my knowledge there have been no published independent studies about the effects of compensation but I will ask our Designers and if they have a link Ill provide it here for your pleasure, however if we as optical people take an objective look at this technology I think we can all see that someone who is a -.25 sph will not see benefits from compensation the same way a person with a -8.00 -2.25 x142 with a +2.25 would in a standard ophthalmic frame. Wrap frames are a different story of course be cause the light incoming to the lens is farther from perpendicular to the eye.

    I generally use a rule of 3's. If the sum distance power is greater that a +3.00 or -3.00 then patients will begin to see benefit from compensation and this sum power value decreases as the angles of the frame become more extreme.

    Its also important to note that certain Rx's are not the best choice for digital lenses over conventional. example Rx:+4.00 with a +2.00 add, in a conventional lens we would choose a 6 base with a 2.00 add. That conventional blank front would be ~6.00 at the top and ~8.00 BC at the near portion with a ~2.00 curve on the back, now being done on a SV blank and surfaced digitally we have ~6.00 on the whole front surface meaning we have a ~2.00 rear curve at the top, and ~ 0.00 at the near. This has a negative effect on the visual acuity of the near area unless a steeper base curve is used (like an 8 base).

    Sharpstick I hope this answered your question.

  7. #32
    Master OptiBoarder OptiBoard Silver Supporter
    Join Date
    Jun 2008
    Location
    Seattle WA
    Occupation
    Optical Wholesale Lab (other positions)
    Posts
    2,841
    Yes... There is some rhetoric out now that for a lens to be "truly" free-form it must include wearer measured and customized face-form, panto, and tilt. I am just trying to crush that rhetoric.

    As well, your points on plus power I have noted in other forums but is seldom discussed, there are limits to FF advantage on higher plus powers.

    Quote Originally Posted by hyperoptic View Post
    By compensated I am referring to ether using an average value, or individual measurments to compensate for, at least in the case of IOT Digital Ray Path technology the oblique aberration experienced by a wearer, our non compensated designs do not take these values into consideration when calculating the back surface of a lens thus providing a digitally surfaced progressive that supplies prescribed power, not compensated power.

    As far as the effect of compensation by percentage, to my knowledge there have been no published independent studies about the effects of compensation but I will ask our Designers and if they have a link Ill provide it here for your pleasure, however if we as optical people take an objective look at this technology I think we can all see that someone who is a -.25 sph will not see benefits from compensation the same way a person with a -8.00 -2.25 x142 with a +2.25 would in a standard ophthalmic frame. Wrap frames are a different story of course be cause the light incoming to the lens is farther from perpendicular to the eye.

    I generally use a rule of 3's. If the sum distance power is greater that a +3.00 or -3.00 then patients will begin to see benefit from compensation and this sum power value decreases as the angles of the frame become more extreme.

    Its also important to note that certain Rx's are not the best choice for digital lenses over conventional. example Rx:+4.00 with a +2.00 add, in a conventional lens we would choose a 6 base with a 2.00 add. That conventional blank front would be ~6.00 at the top and ~8.00 BC at the near portion with a ~2.00 curve on the back, now being done on a SV blank and surfaced digitally we have ~6.00 on the whole front surface meaning we have a ~2.00 rear curve at the top, and ~ 0.00 at the near. This has a negative effect on the visual acuity of the near area unless a steeper base curve is used (like an 8 base).

    Sharpstick I hope this answered your question.
    Beer is proof that God loves us and wants us to be happy ~Benjamin Franklin

  8. #33
    Master OptiBoarder OptiBoard Silver Supporter
    Join Date
    Jun 2008
    Location
    Seattle WA
    Occupation
    Optical Wholesale Lab (other positions)
    Posts
    2,841
    Quote Originally Posted by GokhanSF View Post
    I don't think they are 100% freeform. Just because freeform surfacing is used doesn't mean you get a freeform lens. You also need a lens blank and design. :)
    Free-form is any progressive where any lens has curves modified in any area to improve VA over standard curve powers. Although Shamir trademarked the name, Zeiss first used it 1997 to explain the Zeiss Individual (which later became the "i", and back to the individual). At that time the only Free-form curve was customized atoric compensation for cyl power. Digital CNC lathe surfacing is now the standard way of producing FF but it has been made with thermo micro casting (2C Optics 1996, Warelite Currently) or a "router" type surfacing machine.

    Both the Varilux Physio DRx and Enhanced Fit are back side only lenses with the entire RX processed digitally including distance and add. Essilor uses standard measurments for the DRx for axial length, pupil size, listings law, vertex, and face form, but those are calculated based on human averages. The Enhanced Fit included POW measurements including Face-form, vertex and panto that are specifically measured for each patient.

    Whether they are good or not is another question, but they are without a doubt Free-form.
    Beer is proof that God loves us and wants us to be happy ~Benjamin Franklin

  9. #34
    Banned
    Join Date
    Feb 2012
    Location
    Golden State
    Occupation
    Dispensing Optician
    Posts
    340
    Ok, I got your point. I think we have a different understanding of the term freeform.

    Quote Originally Posted by sharpstick777 View Post
    Free-form is any progressive where any lens has curves modified in any area to improve VA over standard curve powers. Although Shamir trademarked the name, Zeiss first used it 1997 to explain the Zeiss Individual (which later became the "i", and back to the individual). At that time the only Free-form curve was customized atoric compensation for cyl power. Digital CNC lathe surfacing is now the standard way of producing FF but it has been made with thermo micro casting (2C Optics 1996, Warelite Currently) or a "router" type surfacing machine.

    Both the Varilux Physio DRx and Enhanced Fit are back side only lenses with the entire RX processed digitally including distance and add. Essilor uses standard measurments for the DRx for axial length, pupil size, listings law, vertex, and face form, but those are calculated based on human averages. The Enhanced Fit included POW measurements including Face-form, vertex and panto that are specifically measured for each patient.

    Whether they are good or not is another question, but they are without a doubt Free-form.

  10. #35
    The Man, The Myth, The Legend OptiBoard Gold Supporter Fezz's Avatar
    Join Date
    Oct 2004
    Location
    In a van, down by the river
    Occupation
    Dispensing Optician
    Posts
    12,932
    Blog Entries
    9
    Quote Originally Posted by sharpstick777 View Post

    As well, your points on plus power I have noted in other forums but is seldom discussed, there are limits to FF advantage on higher plus powers.
    Why?

  11. #36
    OptiBoard Professional
    Join Date
    Nov 2007
    Location
    Ft Lauderdale, Florida
    Occupation
    Other Optical Manufacturer or Vendor
    Posts
    147
    Quote Originally Posted by Fezz View Post
    Why?
    Hi Fezz,

    Basically its because to use digital designs on plus patients the base curve selection must be made using the highest plus power, cosmetically there would be a mutiny if some one who is a +4.00 +200 add was given an 8 or even 10 base lens to cope with the negative effects of the flatter near vision (this will cause a smaller "sweet spot" and reduce the magnification factor of the NV area of the progressive if a flatter curve is used)

  12. #37
    The Man, The Myth, The Legend OptiBoard Gold Supporter Fezz's Avatar
    Join Date
    Oct 2004
    Location
    In a van, down by the river
    Occupation
    Dispensing Optician
    Posts
    12,932
    Blog Entries
    9
    Thanks.

  13. #38
    OptiBoard Professional
    Join Date
    Nov 2007
    Location
    Ft Lauderdale, Florida
    Occupation
    Other Optical Manufacturer or Vendor
    Posts
    147
    Quote Originally Posted by sharpstick777 View Post
    Yes... There is some rhetoric out now that for a lens to be "truly" free-form it must include wearer measured and customized face-form, panto, and tilt. I am just trying to crush that rhetoric.

    As well, your points on plus power I have noted in other forums but is seldom discussed, there are limits to FF advantage on higher plus powers.
    Honestly I think the word Freeform is used by many lens designers and it is used without consistency, the best thing to do is ignore the buzz words and find out which lenses do what you want for your patients, we all have our own idea of what is best. I want to also say that if the designs are properly used in plus patients the results are stupendous (I am a plus 7.25 and my VA is vastly superior to my conventional lenses, the difference is I made them on a 8.50 base not a 7.)

  14. #39
    Master OptiBoarder OptiBoard Silver Supporter
    Join Date
    Jun 2008
    Location
    Seattle WA
    Occupation
    Optical Wholesale Lab (other positions)
    Posts
    2,841
    Quote Originally Posted by Fezz View Post
    Why?
    Another way, If we use Vogels Rule to determine optimal base curve, the base curve rate in Plus Powers rises fairly quickly. Free-form gives us tremendous ability to fix that (Free-form is still great for plus powers, but not to an infinite point) only to the point where the backside curve starts getting flat. With the add on the back, it gets flat faster than on the add on the front. We can't have a convex lens on the back-side even with Free-form. Free-form works great up to a +4.00 total power (spherical plus add), but after that the advantages decrease with each increase in plus power. Good, but just not as good.

    We see the same thing in minus, the front can only get so flat but its usually so high of an RX that its rarer, and then we could go bi-concave if we wanted to.
    Beer is proof that God loves us and wants us to be happy ~Benjamin Franklin

  15. #40
    Master OptiBoarder OptiBoard Silver Supporter
    Join Date
    Jun 2008
    Location
    Seattle WA
    Occupation
    Optical Wholesale Lab (other positions)
    Posts
    2,841
    Quote Originally Posted by hyperoptic View Post
    Honestly I think the word Freeform is used by many lens designers and it is used without consistency, the best thing to do is ignore the buzz words and find out which lenses do what you want for your patients, we all have our own idea of what is best. I want to also say that if the designs are properly used in plus patients the results are stupendous (I am a plus 7.25 and my VA is vastly superior to my conventional lenses, the difference is I made them on a 8.50 base not a 7.)
    You will gain a lot of advantages with plus powers and FF, but if we could ideally move some of the add to the front, and steepen your backside curve a little, we would gain a little more VA in theory. The only lens that does this now is the Zeiss Individual (German version only) I believe.

    The definition of Free-form has morphed since 1997 when Zeiss first used it to describe a modified and customized atoric cyl curve. Now with more lens choices we have the option of great to mediocre free-form. Its nice problem to have though.
    Beer is proof that God loves us and wants us to be happy ~Benjamin Franklin

  16. #41
    The Man, The Myth, The Legend OptiBoard Gold Supporter Fezz's Avatar
    Join Date
    Oct 2004
    Location
    In a van, down by the river
    Occupation
    Dispensing Optician
    Posts
    12,932
    Blog Entries
    9
    Thanks!

  17. #42
    OptiBoard Professional
    Join Date
    Nov 2007
    Location
    Ft Lauderdale, Florida
    Occupation
    Other Optical Manufacturer or Vendor
    Posts
    147
    Quote Originally Posted by sharpstick777 View Post
    Another way, If we use Vogels Rule to determine optimal base curve, the base curve rate in Plus Powers rises fairly quickly. Free-form gives us tremendous ability to fix that (Free-form is still great for plus powers, but not to an infinite point) only to the point where the backside curve starts getting flat. With the add on the back, it gets flat faster than on the add on the front. We can't have a convex lens on the back-side even with Free-form. Free-form works great up to a +4.00 total power (spherical plus add), but after that the advantages decrease with each increase in plus power. Good, but just not as good.

    We see the same thing in minus, the front can only get so flat but its usually so high of an RX that its rarer, and then we could go bi-concave if we wanted to.
    Speaking from personal experience I will stick with digital compensated lenses because if the proper Base curve is chosen it is certainly better than a conventional alternative, but the key is proper base curve selection which often times makes to much cosmetic compramise.

  18. #43
    Master OptiBoarder
    Join Date
    Aug 2010
    Location
    Austin
    Occupation
    Optical Retail
    Posts
    540
    Quote Originally Posted by TLG View Post
    Check out this chart of digitally surfaced lenses. It describes the front and back surface of each to help give you an idea of what is truly freeform.

    thelensguru.com/digitalChart.php
    I was just looking at your chart yesterday, which is exactly what brought me to the Optiboard (and all over the net) in an attempt to get clarification and lo-and-behold, this thread, and your post! Is Essilor really producing a Free Form, Digitally Surfaced Backside Progressive?


    Quote Originally Posted by GokhanSF View Post
    Essilor doesn't have a true freeform yet, so consider Shamir AutoII, Hoya ID, Zeiss Individual, and Kodak Unique.
    What is Essilor up to here? I'm unclear, are they true free forms?

    http://dualoptix.com/varilux.html

    http://www.luzerneoptical.com/pdf/va...-portfolio.pdf (good for seeing where Dualoptix is applied)

    http://www.luzerneoptical.com/top-wh...e-2.html?sl=EN (video says digitally surfaced)

    http://www.totallyoptical.com/Media/...rt_May2011.pdf
    Last edited by AustinEyewear; 03-17-2012 at 12:35 PM.

  19. #44
    Master OptiBoarder OptiBoard Gold Supporter Judy Canty's Avatar
    Join Date
    May 2000
    Location
    Home Base--Virginia Beach, VA
    Occupation
    Optical Wholesale Lab (other positions)
    Posts
    7,121
    Blog Entries
    4
    Digitally surfaced and free form are NOT the same thing.
    "Jargon is the last refuge of the scoundrel." --Roger Ebert

  20. #45
    Master OptiBoarder
    Join Date
    Aug 2010
    Location
    Austin
    Occupation
    Optical Retail
    Posts
    540
    Quote Originally Posted by CuriousCat View Post
    Digitally surfaced and free form are NOT the same thing.
    Ah, but true free form lenses are digitally surfaced on a CNC machine! Do you happen know the answer to my question above?

  21. #46
    Master OptiBoarder OptiBoard Gold Supporter Judy Canty's Avatar
    Join Date
    May 2000
    Location
    Home Base--Virginia Beach, VA
    Occupation
    Optical Wholesale Lab (other positions)
    Posts
    7,121
    Blog Entries
    4
    Indeed they are, but you can digitally produce any lens design. Digital processing will not make a bad or an old design better. Free form lenses have both the design and the rx digitally produced on the back side of the lens. So in answer to your question, the Varilux DRx lenses are free form, as are products from Zeiss, Seiko, Shamir and Hoya. The point is that you need to understand the technology, not simply depend on the marketing.
    "Jargon is the last refuge of the scoundrel." --Roger Ebert

  22. #47
    Master OptiBoarder
    Join Date
    Aug 2010
    Location
    Austin
    Occupation
    Optical Retail
    Posts
    540
    Quote Originally Posted by CuriousCat View Post
    Indeed they are, but you can digitally produce any lens design. Digital processing will not make a bad or an old design better. Free form lenses have both the design and the rx digitally produced on the back side of the lens. So in answer to your question, the Varilux DRx lenses are free form, as are products from Zeiss, Seiko, Shamir and Hoya. The point is that you need to understand the technology, not simply depend on the marketing.
    Thanks CuriousCat. I have a pretty good handle on what freeform technology is. I won't claim I have a great understanding of optics/physics, but I TOTALLY get what freeform is about. When I look at the Essilor brochure, I'm confused on if they are actually producing a freeform lense. Many people say no. Essilor does not come out and make it a distinct point either, which further confuses me, why wouldn't they just say it clearly? If designed correctly, freeform WILL be a superior technology. The mathmatics prove it. If the machines are calibrated and all variables are kept under control, it is my opinion freeform is superior. But I'm not here to discuss this thoeology. I'm trying to figure out if Essilor ACTUALLY produces a TRUE freeform lense. Whether it be a good or bad design is irrelevant to me.

    From the literature and links I provided, it would seem that they produce several free form lenses, some with a backside CNC surface, and using their latest technology called DUALOPTIX, it appears they are using a CNC machine to surface both sides of the lense. And of course, I am assuming they are using sofisticated software to produce the topograpical maps of the lens surface a.ka. freeform.

    What do you think? Is it the DrX only, the literature seems to say otherwise? What is this DUALOPTIX?
    Last edited by AustinEyewear; 03-18-2012 at 03:14 PM.

  23. #48
    Master OptiBoarder OptiBoard Gold Supporter Judy Canty's Avatar
    Join Date
    May 2000
    Location
    Home Base--Virginia Beach, VA
    Occupation
    Optical Wholesale Lab (other positions)
    Posts
    7,121
    Blog Entries
    4
    You know I wish I could tell you, but I can't. The waters in Dallas are pretty muddy. Perhaps there's a Varilux rep out there who would like to help me out?
    "Jargon is the last refuge of the scoundrel." --Roger Ebert

  24. #49
    Master OptiBoarder MakeOptics's Avatar
    Join Date
    Aug 2011
    Location
    none
    Occupation
    Other Eyecare-Related Field
    Posts
    960
    I use the seiko surmount for my plus patients which is super flat and have never had issues with the lens. I would counter the smaller sweet spot with a wider apparent field of view by moving the constrained surface to the back and even making it convex as is the case with the surmount.

    Also eccentricity can be applied to the front and back surfaces of lenses to counter choices in curves. In the case of plus powers we really can't discus higher plus powers and best form without a discussion of aspherics. A high plus lens can have asphericity applied to one or both surfaces to imporve optics. When applied to the front eccentricity flattens the curve, to the back steepens the curve, the overall effect for all intensive purposes is the same.

  25. #50
    Master OptiBoarder TLG's Avatar
    Join Date
    Feb 2007
    Location
    S. California
    Occupation
    Dispensing Optician
    Posts
    795
    Quote Originally Posted by AustinEyewear View Post
    I'm trying to figure out if Essilor ACTUALLY produces a TRUE freeform lense. Whether it be a good or bad design is irrelevant to me.
    What do you think? Is it the DrX only, the literature seems to say otherwise? What is this DUALOPTIX?
    Well, the Ipseo is also full freeform but nobody uses that so that leaves the DRx. ALL of the other Physio flavors have a molded front PAL design and are 'digitally surfaced' on the backside; yes, the front side mold IS cast from a digitally surfaced glass mold and yes, they ARE cut on CNC generators... but few people (outside of Essilor) would agree that that make it 'freeform' - it is not. As far as "dual add" goes, consider that half of the 'duo' is molded onto the front, with the other half - and the rest of the PAL design and Rx - digitally surfaced on the back. I'll let you decide if that is a 'true' freeform.
    Essilor is far from alone in being vague about their product technology.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. freeform progressive lens
    By au in forum Progressive Lens Discussion Forum
    Replies: 18
    Last Post: 08-19-2010, 04:47 PM
  2. Freeform Lens Production...?
    By DMdrummer13 in forum General Optics and Eyecare Discussion Forum
    Replies: 9
    Last Post: 05-15-2010, 10:08 AM
  3. FreeForm Lens- Whats the best?
    By mm92103 in forum Progressive Lens Discussion Forum
    Replies: 12
    Last Post: 04-30-2010, 07:34 AM
  4. Freeform lens Mapper
    By mahmoud.hamza in forum Progressive Lens Discussion Forum
    Replies: 3
    Last Post: 01-19-2010, 01:01 PM
  5. Ordering 1 freeform lens
    By TLG in forum General Optics and Eyecare Discussion Forum
    Replies: 6
    Last Post: 01-16-2010, 03:31 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
OptiBoard is proudly sponsored by:
FEA Industries, Younger Optics, Carl Zeiss Vision, Vision Systems, Inc. and Chemistrie Eyewear