Rotation of lenses throughout the day - Preference Toric

Discussion in 'Optometry Archives' started by Alex Sanielevici, Mar 4, 2004.

  1. I'm hoping some of the MDs on this board can recommend possible
    solutions to this problem with my right CooperVision Preference toric

    I recently ordered new lenses from my ophtalmologist. My right eye
    starts out with perfect vision at the beginning of the day, centering
    perfectly on its own, but the lens keeps rotating to a different
    position (subtracting axis) after the first 15-30 mins, especially
    during times when I'm reading or looking at the computer (I suspect
    due to eye position during closer convergence). After the first few
    hours, it almost consistently goes to this second position, and
    turning the lens back slightly towards its original position produces
    perfect vision, but usually only for a few minutes.

    When I see perfectly, the reference mark (which should point straight
    down at 0 rotation) is very slightly off-center, pointing to the right
    corner of my mouth. When the reference mark points straight down, I
    see ok but not great, and when it rotates slightly past center (ever
    so slightly towards my right cheek), the vision is unacceptable. I can
    see the reference mark using an LED flashlight.

    Other than rotating it back into position, I find that a change in
    conditions (going outdoors and looking far away, or taking a shower)
    often resets the lens and I see well for a while.

    The left eye is quite stable all day. Why would the right lens rotate
    to a negative axis as the day wears on? Is there a way to get a lens
    to be more stable in the right eye? How much total rotation does the
    range described represent? Do I need a different curvature or a lens
    with different characteristics?

    My eyeglass prescription for the right eye:

    OD -5.75 cyl -2.25 axis 166

    My contact lens prescription for the same eye:

    OD -5.25 cyl -1.75 axis 165

    I would appreciate any ideas -- Alex.
    Alex Sanielevici, Mar 4, 2004
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  2. Alex Sanielevici

    Dr Judy Guest

    Return to your fitter, book the appointment so you have been wearing the
    lenses for a few hours and tell him about the problem, including that the
    best vision is with the lens slightly rotated. Your fitter can then
    precisely measure the number of degrees of rotation and reorder the lenses
    with the correct axis. No charge exchange for axis adjustment should be
    included in the fee you paid for fitting.

    Dr Judy
    Dr Judy, Mar 4, 2004
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  3. If I order lenses that fit the second position (+5-10 deg), I will no
    longer see well when the lens is in the first position... I will
    simply invert the problem.

    One solution is to get something between the two so I see marginally
    at both positions but well in between... but the question is why
    progressive motion to the second (minus) as the day advances, and how
    to get lenses that stay in one position so I can settle on one axis?

    -- Alex.
    Alex Sanielevici, Mar 5, 2004
  4. Alex Sanielevici

    Dr Judy Guest

    In your first post you stated that the lens changes after 15 to 20 minutes
    of wear. This is common with toric lenses and surely it is better to be
    clear for 12 hours and blurry for 15 minutes than vice versa.

    If the lens is not fitting properly it may rotate less predictably. If this
    is the case, you need to see your fitter to adjust fit which may mean
    changing lens brand.

    Dr Judy
    Dr Judy, Mar 6, 2004
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