Results 1 to 16 of 16

Thread: Digitally Surfaced?

  1. #1
    ATO Member HarryChiling's Avatar
    Join Date
    Apr 2005
    Location
    Nowhereville
    Occupation
    Other Eyecare-Related Field
    Posts
    7,765

    Digitally Surfaced?

    Ok we had the Valrilux rep in today and she kept saying that now all their lenses are digitally surfaced. After talkign to her for some time she finally confessed to digitally molded and traditionally surfaced.

    I like the fact that the molds are now being digitally created instead of slumped, but come on now "digitally surfaced", thats a little on the ridiculous. So the whole free form processing has opened up a whole new game for the marketing folks at these large lens manufacturers.
    1st* HTML5 Tracer Software
    1st Mac Compatible Tracer Software
    1st Linux Compatible Tracer Software

    *Dave at OptiVision has a web based tracer integration package that's awesome.

  2. #2
    OptiBoard Professional
    Join Date
    May 2004
    Location
    all over
    Occupation
    Other Optical Manufacturer or Vendor
    Posts
    130

    progressives

    My free form progressives are surfaced by exiled trappist monks in Paraguay and a portion of the proceeds helps fund their revolution which is way better than that digital crap.

  3. #3
    Independent Problem Optiholic edKENdance's Avatar
    Join Date
    Dec 2000
    Location
    In the Middle
    Occupation
    Optical Retail
    Posts
    2,630
    I guess this answers my Nikon Digital thread question too. :cheers:

  4. #4
    Master OptiBoarder
    Join Date
    Feb 2007
    Location
    NC
    Occupation
    Dispensing Optician
    Posts
    3,951
    The king on spin, Hell, they shortened the fitting heights without ever changeing anything. Its there game, we just get to play along

  5. #5
    Master OptiBoarder TLG's Avatar
    Join Date
    Feb 2007
    Location
    S. California
    Occupation
    Dispensing Optician
    Posts
    814

    Confusion reigns

    One of the newest lenses boasts "Direct Digital Surfacing" which implies the digital surfacing technique is applied directly to the surface of the lens. It is actually applied to the mold. If you read carefully it does say in the mold, but the name is very deceptive I think.

    I agree, I think digitally surfaced molds are preferable and a great step forward, but this one just adds to the confusion of these new breeds.

  6. #6
    Master OptiBoarder optigrrl's Avatar
    Join Date
    Feb 2005
    Location
    The surface of the sun on a rainy day
    Occupation
    Other Optical Manufacturer or Vendor
    Posts
    1,336

    Imho

    From what I have been able to figure out is that these digital-surfaced pal's use point files to further finite the curvature changes between the power changes in the design when it's ground in a pre-cast base curve.

    So it seems that there is the traditional pal - pre-cast 3 to 4 base front curve, stock add then distance rx power ground into the design, digital point-file to further smooth out the abberation caused by power change and free-form: start-from-a-hockey-puck-slab-of-plastic with no pre-cast anything give the patient their optics technology.

    But we really need Darryl to better explain...

  7. #7
    Master OptiBoarder rbaker's Avatar
    Join Date
    May 2000
    Location
    Gold Hill, OR
    Occupation
    Other Optical Manufacturer or Vendor
    Posts
    4,401
    The reason that this marketing is so successful is that he vast majority of those working in the eye care vineyard are ignorant of ophthalmic optical theory and manufacturing methods. The lens salesman parrots the sales pitch to the optician and the optician parrots it to the customer. And, so it goes - on and on.

  8. #8
    ATO Member HarryChiling's Avatar
    Join Date
    Apr 2005
    Location
    Nowhereville
    Occupation
    Other Eyecare-Related Field
    Posts
    7,765
    Traditional mold making involves:

    • Blank Prep
    • Mould Prep
    • Mould Assembly
    • Slumping or Sagging
    • Inspection
    • Engraving
    • Toughening
    The blank prep is done with a chunk of molten glass called a parison, which is falls into a metal mold and is squeezed into a certain volume and at this stage becomes a pressing, this pressing further gets surfaced on both sides to predetremined spherical curves and polished (this process requires strict quality control of the glass surfaces). The mould is prepared from a ceramic blank, which is then CNC cut (known to us as free form processing) The glass blank then gets put togther with the mould and heated so that the glass reaches a temperature where it starts to sag into the mould, the glass surface sags untill it touches the mould, taking on the topographical properties of the mould and the back surface of the glass as well takes on the properties of the mould. These glass moulds are inspected for accuracy to the original design and then engraved with their markings. The glass mould can now be used to make ophthalmic plastic lens from.

    The difference between the process of slumping or sagging and the digitally surfaced is in how the glass mould is made. In digitally surfaced moulds the glass mould is surfaced in the CNC lathe rather than the ceramic mould and the process of slumping is eliminated. Yes it gives more accuracy to the glass moulds that the lenses are cast from, but the lenses themselves are not digitally surfaced, which the manufaturer is hoping you are not smart enough to figure out.

    Quote Originally Posted by optigirl
    So it seems that there is the traditional pal - pre-cast 3 to 4 base front curve, stock add then distance rx power ground into the design, digital point-file to further smooth out the abberation caused by power change and free-form: start-from-a-hockey-puck-slab-of-plastic with no pre-cast anything give the patient their optics technology.

    But we really need Darryl to better explain...
    So what is happening is there are now:
    1. Slumped pre-cast progressives
    2. Digitally surfaced pre-cast progressives
    3. Digitally surfaced pre-cats progressives with one side free form processed
    Not only does that muddy up the waters, but you have the backside freeform progressives which even further muddy the waters, because the can be using slumped SV lenses to process, Digitally surfaced SV lenses to process, or Aspheric in also both flavors.

    The manufacturers are going to muddy up the waters with all these terms is the point I am getting at and since free form is still in it's infancy, the waters are not as convaluted as they could be. I would appreciate if they would just call a spade a spade.
    1st* HTML5 Tracer Software
    1st Mac Compatible Tracer Software
    1st Linux Compatible Tracer Software

    *Dave at OptiVision has a web based tracer integration package that's awesome.

  9. #9
    Master OptiBoarder
    Join Date
    Feb 2007
    Location
    NC
    Occupation
    Dispensing Optician
    Posts
    3,951
    Harry, very enlightening , but I think you have too much free time on your hands, Come down to the beach and work with me. ( you know what they say, surround yourself with people smarter than you.)

  10. #10
    Master OptiBoarder optigrrl's Avatar
    Join Date
    Feb 2005
    Location
    The surface of the sun on a rainy day
    Occupation
    Other Optical Manufacturer or Vendor
    Posts
    1,336
    Harry - Thank you for the clear explaination.

  11. #11
    Optical Educator
    Join Date
    May 2000
    Location
    Tampa, Florida
    Occupation
    Dispensing Optician
    Posts
    1,044

    digital processing

    Hello,

    As advancements of PAL manufacturer continue, it is all the more important that we keep up.

    Freeform can mean:

    Freeform Optics: digitally created mold, bypassing the ceramic-to-glass mold process, and combining a ray-tracing program like Eyepoint Technlogy (R) to simulate human vision, and incorporate into the design. Once the design is set, it is digitally created in the mold, Vs. creating a ceramic model, and then a glass mold.

    Personalized Freeform: Applying freeform manufacture to the back surface, starting with a spherical BC on the front. Patient/Frame data can be incorporated, creating a personalized PAL through freeform technology. All of this is done on the back surface, which yields better vision, with better fields of view. Bringing the optics to the back surface is a huge advancement in PAL manufacture.

    When you hear about "point file system", it likely refers to an "X,Y,Z" file. Where X and Y are in the same plane (horizontal, and vertical, like Toric Base Curve and Cross Curve), the Z file can go in and out. Because the Z file can create depth and curvature, this can be applied to the front or the back. Super computers enable the designers to bring a model to market much faster than in the past.

    Hope this helps,

    : )

    Laurie



    If it is applied to the back,incorporating patient/frame data, it is personalized freeform.

    Hope this helps,

    : )

    Laurie

    If it is applied to the front (as in digital molds),

  12. #12
    Allen Weatherby
    Join Date
    Jun 2004
    Location
    Florida
    Occupation
    Other Optical Manufacturer or Vendor
    Posts
    1,286

    What Does It All Mean???

    Quote Originally Posted by HarryChiling View Post
    Ok we had the Valrilux rep in today and she kept saying that now all their lenses are digitally surfaced. After talkign to her for some time she finally confessed to digitally molded and traditionally surfaced.

    I like the fact that the molds are now being digitally created instead of slumped, but come on now "digitally surfaced", thats a little on the ridiculous. So the whole free form processing has opened up a whole new game for the marketing folks at these large lens manufacturers.
    Harry:

    This gives me a whole new marketing approach for ICE-TECH Advanced Lens Technologies. "Truth in digitally surfaced lenses"

    I read some of the companies literature and I don't know what they mean by digitally surfaced.

    PS: Many molds have been made for years and years using digital surfacing. They just now figured it was of some benefit to tell their customers. (With a little confussing spin)

  13. #13
    Optical Educator
    Join Date
    May 2000
    Location
    Tampa, Florida
    Occupation
    Dispensing Optician
    Posts
    1,044

    digital molds

    Hi AWTECH,

    You are correct, in that digitally-created molds have been known for a while now.

    In fact, if a company has been in the mold-making business for years, they are well equipped to go forward with this exciting new process of manufacture, and will be ahead of the curve in bringing it to market.

    : )

    Laurie

  14. #14
    Bad address email on file
    Join Date
    Oct 2006
    Location
    San Diego Ca.
    Occupation
    Dispensing Optician
    Posts
    73

    20/20

    http://www.2020mag.com/Supplements/V...1/Default.aspx




    Quote Originally Posted by HarryChiling View Post
    Ok we had the Valrilux rep in today and she kept saying that now all their lenses are digitally surfaced. After talkign to her for some time she finally confessed to digitally molded and traditionally surfaced.

    I like the fact that the molds are now being digitally created instead of slumped, but come on now "digitally surfaced", thats a little on the ridiculous. So the whole free form processing has opened up a whole new game for the marketing folks at these large lens manufacturers.

  15. #15
    Master OptiBoarder Darryl Meister's Avatar
    Join Date
    May 2000
    Location
    Kansas City, Kansas, United States
    Occupation
    Lens Manufacturer
    Posts
    3,700
    Regardless of the mold-making process involved, all progressive lens molds require a computer-controlled milling machine or "free-form" type generator at some stage. For that matter, many polycarbonate progressive lenses have always relied on directly surfacing the molds.

    Further, regardless of whether the mold has been directly surfaced or slumped, the final lens will not replicate exactly the mold design because of shrinkage (around 14% for hard resin) and other factors. The mold may still need to be "iterated" by measuring actual production samples and applying optical compensations to the original mold design.

    Some lens manufacturers, such as ZEISS, have been directly surfacing glass molds for many years. Other lens manufacturers, such as SOLA, have been using slumping, instead. Each approach has its advantages and disadvantages. While directly surfacing the lens mold may result in a closer replication of the optical design in many cases, it is also subject to more variance. Slumping, on the other hand, is a highly repeatable process that produces consistent results from lens to lens with less variation between runs.

    The real confusion here lies in the difference between mold making and lens making. A "free-form" or "digitally surfaced" lens is a lens surfaced using a free-form generator and polisher. It is not simply a lens that has been cast from a "digitally surfaced mold." If this were the case, a majority of the lenses on the market could be called "free-form" lenses.

    It is equally important to note that a "free-form" lens doesn't really imply any greater level of optical performance or sophistication. Unless the lens has actually been customized for the wearer in "real time" by lens design software, prior to free-form surfacing, the performance of a free-form progressive lens is really no different than a comparable semi-finished lens. I think some manufacturers, with limited lens design tools, sometimes exploit this misunderstanding of the term "free-form" by implying that, because their progressive lens came off a free-form generator, it is similar in technology to some of those premium, customized free-form lenses out there -- like Gradal Individual, Varilux Ipseo, etcetera.

    ps,
    I also think the term "digital surfacing" is a bit of a misnomer; all modern generators use computer-numerically-controlled cutting.
    Last edited by Darryl Meister; 03-13-2008 at 11:02 PM.
    Darryl J. Meister, ABOM

  16. #16
    ATO Member HarryChiling's Avatar
    Join Date
    Apr 2005
    Location
    Nowhereville
    Occupation
    Other Eyecare-Related Field
    Posts
    7,765
    Quote Originally Posted by Darryl Meister View Post
    The real confusion here lies in the difference between mold making and lens making. A "free-form" or "digitally surfaced" lens is a lens surfaced using a free-form generator and polisher. It is not simply a lens that has been cast from a "digitally surfaced mold." If this were the case, a majority of the lenses on the market could be called "free-form" lenses........ps,
    I also think the term "digital surfacing" is a bit of a misnomer; all modern generators use computer-numerically-controlled cutting.
    Thank you, the terms are being created and used to exploit what little opticians may know about the process and the creation of lenses. I think that's funny that you mentioned poly lenses being "digitally surfaced". It's just ridiculous and does nothing more than create confusion. I think to use the term "free-form" the lens should include optimizations for the individual, otherwise I don't care how you created your lenses, it could be the keebler elves making it for all I care.

    Why not call them "Digitally Cast"?
    1st* HTML5 Tracer Software
    1st Mac Compatible Tracer Software
    1st Linux Compatible Tracer Software

    *Dave at OptiVision has a web based tracer integration package that's awesome.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Frustrated about digitally surfaced PALs
    By Bobbi in forum Progressive Lens Discussion Forum
    Replies: 39
    Last Post: 04-30-2010, 09:07 AM
  2. stock vs lab surfaced lenses
    By kenjmeister in forum General Optics and Eyecare Discussion Forum
    Replies: 6
    Last Post: 04-11-2006, 07:51 AM

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
  •