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Soldering eyeglass Frames

Discussion in 'Electronic Repair' started by [email protected], Jan 20, 2008.

  1. Okay. How am I supposed to get it, if not from a local optician?

    I assume you're kidding. Can you imagine how many millions of pre-ground
    "stock" lenses would be needed to every possible combination of lens size &
    shape, PD, prescription, etc? There probably aren't that many atoms in the
    universe! <grin>
     
  2. Guest

    He's not kidding. That's how all those "eyeglasses in a hour" places
    do it. They stock an assortment of ready made lenses. The "blank"
    lenses are large circles. They simply cut them to fit the frames you
    picked out. The size, shape, and PD are irrelevent, as they cut from
    the large blank which has it's optical center in the center.
     
  3. I assume you're kidding. Can you imagine how many millions of
    I could see this if all you were correcting for were single refractive
    errors. But lenses also require astigmatism correction. Not to mention the
    different types of lens materials, coatings, etc -- and bifocals, trifocals,
    progressives, etc.

    Furthermore, it would make no sense to stock all these variations, simply
    because of the capital investment involved. A store can't afford to keep
    rarely needed prescriptions in stock.

    Finally... The lens has to be "ground" at some point, regardless of whether
    it's in China or the US. Are you suggesting that it would take an automatic
    machine more than a few minutes to do this -- while the technician was doing
    something else?

    Nope. I still don't buy it.
     
  4. Ron(UK)

    Ron(UK) Guest

    The pre-ground stock lens fits in a machine with the correct profile
    follower for the frame. This guides a grinding wheel to remove excess
    material from around the edges of the lens until it will fit the chosen
    frame. a profiled wheel shapes the newly ground edges to give the lens a
    'lip' which holds it in the frame. I`ve seen it done, it doesn't take
    long. The hard coating takes longer than the grinding.


    Ron(UK)
     
  5. John Smith

    John Smith Guest

    Two pair cost me about $70.00 USD to order (shipping stays the the same,
    $4.95 USD, no matter how many pairs you order!)

    Even if he is fibbing, maybe it will work out. At least at that price,
    I won't be disappointed longer than a couple of hours. <LOL>

    Regards,
    JS
     
  6. Goedjn

    Goedjn Guest

    On Tue, 22 Jan 2008 01:04:16 +0000 (UTC),
    Fence wire, and modeling paint.
     
  7. Guest

    You can argue all you like, but the fact remains, there are stores in
    just about every town of any consequence and most large malls that do
    exactly what I said. One example is Lenscrafters, which has over 800
    locations. I am simply astounded to find someone who isn't aware of
    them, as they advertise this like mad on radio, TV and in print.
     
  8. Of course I'm aware of LensCrafters -- I've bought glasses from them. I
    simply don't believe that they have tens of thousands of lenses that have
    been pre-ground to every conceivable prescription. It's not an economically
    efficient way to run a business.

    I just remembered something... You can request these companies to grind the
    frontal radius of the lens to match the radius of your previous lens. This
    wouldn't be practical if the lenses were pre-ground.

    I'll back off on this issue for the time being. The next time I'm near
    LensCrafters or a similar company, I'll ask.
     
  9. Guest

    Apparently, it IS an economically efficient way to run a business.
    They have been hugely succesful. For openers, do you have any idea
    what mass produced molded plastic lenses cost a place like
    Lenscrafters? A dollar each? Less? The markups in the optometry biz
    are astronomical. Stocking enough lenses to cover 90% of the people
    who walk through the door isn't nearly the expense you think it is.
    Especialyy when they can stock shallow and the inventory system
    automatically reorders as they are drawn from stock. The inventory
    even knows which ones move faster, and adjusts accordingly.

    Yeah, so for the small minority iof cases where a customer needs
    something special, they make a phone call to the main warehouse and
    tell the customer that they have to come back tomorrow. Overnighting a
    pair of lenses is no problem when you are making $300-500 profit on a
    pair of glasses.
     
  10. John Smith

    John Smith Guest

    I can understand how plastic lens are quick and no big problem.

    What amazes me is that it seems no longer to get the glass lens--but,
    these are being offered less and less often ...

    Regards,
    JS
     

  11. You might be right about all this. Who provided you with this information
    about stocking all or most of the the blanks?
     

  12. "offered"? You mean, you ask for them and you're told they no longer sell
    them? Or, you don't ask and they don't mention glass as an option?
     
  13. John Smith

    John Smith Guest

    True, I just don't see them offered. At the price I have been paying
    for plastic--I am scared to!

    Regards,
    JS
     
  14. R -2.50-0.50x174
    L -3.00-1.25x175

    PD=71

    temple=140mm-
    57/16 or 52/16
     

  15. Looks like an easier prescription to fill than mine. I actually walked into
    3 eyeglass places where they could measure everything themselves. All 3 of
    them screwed it up BIG time. This offshore thing is obviously not for
    everybody.
     
  16. You don't understand. It takes a small number of stock lenses to cover
    almost all the population for single-vision lenses. All you need are small
    set of increments of spherical powers crossed with a few astigmatic
    cylinder increments. These are stocked as big circular blanks.

    Size and shape to fit the frame, PD centering, astigmatism angle, etc., are
    all fitted with a jig that cuts the big round blank to a final shape,
    center, and cylinder angle. The "optician" doesn't grind the optical
    surfaces.

    Now, bifocal adds, progressives, extreme Rx powers, are another matter.
    But even those tend to be jobbed out to factories, not done by local
    craftsmen any more. And those factories are increasingly found overseas in
    an age of air transport.
     

  17. Twice in 25 years, my optician has gotten lenses back from the "lab",
    installed them in the frames I already owned, put them on me, and said
    "These are not quite right." He was correct. They were weird. He gave me
    the option of putting the old ones back in and coming back when the
    replacements were done, or living with the "rejects".

    It's worth a few hundred bucks to some people to know that what they're
    getting is perfect the first time.
     
  18. I agree. Dull minds have to pay more for the same results. You cannot
    shop price when you don't understand what you're buying. Guild-mentality
    opticians have an incentive to keep us ignorant. Intelligent, critical
    thinkers, with the Web at hand, can bust that racket.
     

  19. How is an offshore supplier supposed to measure the distance between pupils,
    and determine frame size?
     
  20. Please share your prescription with us.
    http://en.wikipedia.org/wiki/Eyeglass_prescription

    Both eyes are nearsighted. The first requires a cylindrical (astigmatic)
    correction of -0.5 diopters at an angle of 174 degrees.

    Note that the angles are in one-degree increments. Is the store supposed to
    stock 180 different versions of a lens with -2.5 diopters refraction and -.5
    diopters cylindrical? You'd need at least 10,000 different lenses to cover
    the common combinations. Even if the cylindrical were limited to 5-degree
    increments, you'd still need a huge number of lenses.

    No, no, no, no, no. I don't believe it.
     
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