RGP contact lens prescription question

Discussion in 'Contact Lenses' started by tenplay, Aug 6, 2005.

  1. tenplay

    tenplay Guest

    I am very near-sighted - -10.75 R, -8.25 L. Before I went in for my
    annual exam last week, my L lens prescription was -9.25. In the exam, I
    could see only 20/40 with my L lens. So the doctor changed the
    prescription to -8.25. Now I am confused. If my eyes got worse,
    shouldn't the -9.25 have been increased to -10 or so? It seems
    backwards to me. Can anyone explain?
    tenplay, Aug 6, 2005
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  2. tenplay

    otisbrown Guest

    Dear Tenplay,

    You should ask you doctor about this.

    If you want the stronger minus -- I am
    certain he will provide it.

    There are doctors who believe that
    a very strong minus results in
    your vision going "down" at a
    steady rate -- and will attempt
    to "under-prescribe" for that

    You should ask him to explain, and
    -- if that is the case -- then he
    should have explained before
    he gave you a "reduced" prescription.


    otisbrown, Aug 6, 2005
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  3. tenplay

    Dr. Leukoma Guest

    You neglected to say whether the reduction in prescription made your
    vision better or worse.

    The goal of prescribing for myopia is to give only the power that is
    required to achieve clear, comfortable vision at far...no more and no
    less. There are various techniques for determining this. The eye
    doctor must have determined that your prescription was too strong, not
    too weak, and made the necessary adjustment. By itself, a Snellen
    acuity of 20/40 says nothing about the cause. You could be farsighted,
    nearsighted, astigmatic, a combination of the above, or have a retinal

    Dr. Leukoma, Aug 6, 2005
  4. tenplay

    p.clarkii Guest

    if you are a hammer, everything looks like a nail
    p.clarkii, Aug 7, 2005
  5. tenplay

    Dr. Leukoma Guest

    Since I glossed over the fact that this patient is wearing RGP lenses,
    I will add to what others have already written by saying that I have
    long observed a trend in RGP lens wearers of having to adjust the
    prescription downward over time. Presumably this is due partly to the
    effects of changing corneal shape as a result of wearing the lenses.

    Dr. Leukoma, Aug 7, 2005
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