Distance vision area on a progressive lens

Discussion in 'Eye-Care' started by Mark A, Jan 27, 2007.

  1. Mark A

    Mark A Guest

    Does the distance vision on a typical progressive lens (+4.75 -1.75 x90 with
    +2.25 add in my example) maintain the same power all the way up to the top
    of the lens? Assume a frame that is 40mm high with a fitting height of
    about 24mm. Lens is Zeiss Individual.

    On my new lenses, the distance vision appears a bit less sharp at the top of
    the frame. I am not sure if that is because my Rx is too weak in the
    distance area, or if that is normal. I am also not sure if it is because my
    best distance vision is actually using part of the intermediate corridor and
    picking up a bit more strength to achieve my best distance vision.
     
    Mark A, Jan 27, 2007
    #1
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  2. Mark A

    Mark A Guest

    What I mean is that when I raise the frame up about 3 mm (keeping my head
    straight), the distance is clear. I did this to see if the fitting height
    was too low. But I cannot tell if the reason for sharper distance vision
    when the frame is raised 3 mm is because of the fitting height is measured
    wrong, or because the Rx is wrong (and I am picking up some extra needed
    power in the intermediate area).

    I am getting a recheck of the Rx, but I was wondering if I should be able
    see clearly out of the distance portion, even if the fitting height is 3 mm
    too low.
     
    Mark A, Jan 29, 2007
    #2
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  3. Mark A

    Mark A Guest

    The reading area did seem quite short on the new lenses, but otherwise the
    sharpness was OK. Only the sharpness of the distance area was a problem. The
    above taken together (along with my own FH measurements) led me to believe
    that the fitting height was too low.

    I had the refraction checked by another OD, and it is OK. The "designated
    expert" in the optical shop re-measured my fitting height and determined
    that it was 4mm too low (which was obvious to me according to my own
    measurements). The original measurement was 22mm on a 39mm high lens
    (Autoflex 41 56-19). It was re-measured to 26mm. I will let you know the
    results when the new lens (Zeiss Individual) comes back from Germany in
    about 2 weeks.

    BTW, the guy who originally fitted me was about 50 years old, and he claimed
    that he had personally fitted about 150 pair of Zeiss Individuals (I asked
    him).

    Because I am fairly tall and taller than most opticians when we are both
    sitting down or both standing up, it is often a problem getting a good
    fitting height measurement.

    Most people do not complain when they get bad glasses. When I was 16 years
    old I went to an ophthalmologist and he did the eye drops before the
    refraction, and my glasses were so strong I never wore them. I complained to
    my parents, but no complaint was ever lodged with the MD.
     
    Mark A, Jan 31, 2007
    #3
  4. Mark A

    Mark A Guest

     
    Mark A, Feb 1, 2007
    #4
  5. Mark A

    Mark A Guest

    You are correct. My new frame is the Autoflex 47 56-19. The height is 39mm
    (40.4 according to manufacturer). My old frames are Autoflex 41.
    My first pair of Zeiss Individual came back in 11 days (about a week ago).
    The technician who measured my remake said that he also changed the
    pantoscopic angle, so that may also be somewhat of a factor. I don't know
    what the original PA was, nor do I recall what he changed it to.
     
    Mark A, Feb 1, 2007
    #5
  6. Mark A

    Mark A Guest

    The optical shop said it goes to Germany. Either they don't really know, or
    it is just the right time of year for quicker turnaround. Or maybe the don't
    ship everyday, and I just hit the right time of week. I checked the
    etchings, and it was a Zeiss Individual 1.6.
     
    Mark A, Feb 2, 2007
    #6
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