regular plastic in drill mounts?

Discussion in 'Optometry Archives' started by AJ, Aug 25, 2005.

  1. AJ

    AJ Guest

    I've been having a bit of trouble adjusting to the trivex lenses in my
    drill mount frames and the office said they can have the lab put
    regular plastic lenes in these. Some labs won't do it and others will
    do it but with a shorter warranty period. I've always heard you HAD to
    use high index, stronger lenses with drill mounts due to splitting or
    splintering. Any thoughts? So far I'm a bit hesitant but I do notice
    the difference in optics vs. my normal lenses.
     
    AJ, Aug 25, 2005
    #1
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  2. Most labs won't do it because the plastic WILL break at the drill points
    unless you are fanatically careful with them.

    I'm concerned about your problems with Trivex, which I dearly love. Was
    there an Rx change? I'd suspect a difference in Rx before I'd suspect
    Trivex being at fault, unless you just got a bad lens. What kind are
    they (single vision, bifocal or progressive)? If progressive, what
    brands old and new?

    w.stacy, o.d.
     
    William Stacy, Aug 25, 2005
    #2
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  3. AJ

    AJ Guest

    The prescription is the same between the plastic and trivex lenses. I
    have astigmatism so that enters into the equation. They checked the
    glasses with my current ones and there was no difference but stated
    that some patients are sensitive to the higher index lenses. I did
    notice that things seemed shorter...or that the ground came up a bit
    vs. my plastic lenses.

    This is the third set of lenses in these frames as with the first ones
    the OC was wrong. The second had basically no base curve and these seem
    to have more of a bc than my plastic lenses. They're much better and I
    think I can get used to them...but my vision is not as accurate with
    these lenses.
     
    AJ, Aug 25, 2005
    #3
  4. You still didn't say if they are SV, Bi or Prog. Also, do the lenses
    have a very faint greenish tinge when you hold them over a piece of
    white paper?

    w.stacy, o.d.
     
    William Stacy, Aug 25, 2005
    #4
  5. AJ

    AJ Guest

    They are SV. They have AR which gives a faint green reflection when you
    hold them just right.
     
    AJ, Aug 26, 2005
    #5
  6. OK my reason for asking that was that Trivex lenses actually have a very
    slight greenish tint to them, in addition to or rather separate from the
    greenish reflection from the coating. Try the test again, but tilt them
    so that all reflections are directed away from your eyes. If they are
    really Trivex, you will see a slight green color of the lens itself (you
    might be able to more readily see this tint by looking straight at the
    edge. If they are not so tinted, and are "dead white" you didn't get
    Trivex, you probably got polycarb...

    w.stacy, o.d.
     
    William Stacy, Aug 26, 2005
    #6
  7. AJ

    AJ Guest

    Hmmm, there is a slight tint but I don't think I would call it green.
    Maybe more of a very, very slight gray or brown...very slight. The
    edges are polished and I can't pick up any hint of green when looking
    at them. Is there any other way to distinguish trivex from poly? Since
    I clearly paid for trivex from my fee slip, I'd be very disappointed if
    it was instead poly, especially since I've lamented to the opticians
    that I don't care for poly due to the reduced optics. The other thing
    I've found odd (again, maybe not a big deal but...) is that these
    lenses don't seem much thinner than my regular plastic lenses. Thanks
    for you help.
     
    AJ, Aug 29, 2005
    #7
  8. AJ

    Mark A Guest

    Trivex (1.53 index) is not much thinner than regular plastic (1.50).
    Polycarb is 1.59.

    However Trivex is significantly lighter than regular plastic or polycarb:

    Regular Plastic (CR-39) 1.32 g/cm3
    Polycarb 1.20 g/cm3
    Trivex 1.11 g/cm3

    What brand of Trivex did you get? Hoya Phoenix or Younger Trilogy? If they
    are progressives then they will have etchings that identify the lens design
    and material.
     
    Mark A, Aug 29, 2005
    #8
  9. I'm not sure why you say that. I use a fair amount of Trivex and have
    not het ordere an aspheric one. I have a bias against aspheric lenses,
    maybe because of your comment above...
    I also detest the "flatter is better" mantra that seems to be so popular
    these days. I hate the mirror effect that flat lenses give, and I
    really don't agree that they "look better". I agree that there is a
    theoretical "best" base curve for every Rx, but this can be and is often
    changed for a variety of reasons (maybe not with aspherics (??), but
    then, as I said, I never use aspherics unless there is no other choice).

    w.stacy, o.d.
     
    William Stacy, Aug 29, 2005
    #9
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