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Thread: Patient seeing round objects as ellipses.

  1. #1
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    Patient seeing round objects as ellipses.

    Hello everyone, I'm wondering if I can use everyone's experiences in practice to solve this dilemma.

    I have a patient who complained of seeing round objects as ellipses in his previous spectacles (2 years old). He was re examined, new refraction found the same prescription right and left with a small change in axis (give or take 5 degrees) and a slight increase in near add.

    On the collection of the new spectacles the same problem was experienced and no improvement after 2/52 of constant wear.
    The same lens design and corridor length have been used with no change in centration, base curve, vertex distance, pantoscopic tilt or wrap.

    The optometrist is adamant the RX is fine. Should I push for a re-check?

    Thanks

  2. #2
    Master OptiBoarder OptiBoard Gold Supporter
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    Change in add? Does he have a pair where this phenomena does not occur? What is the RX/PD in those compared to the new ones. Round objects in distance, or up close? You need to ask a long list of specific questions in these types of situations.

    Also if you entered custom POW values you need to make sure that the frame in its current dispensed state is 100% at those values, especially the wrap. The last time I saw this was on a pair that was supposed to have 10 wrap but after finishing and dispensing it was sitting closer to 4 degrees, adjusted and it got better.

  3. #3
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    I agree with wrap differences. Also cyl and axis changes.

  4. #4
    Master OptiBoarder OptiBoard Silver Supporter lensmanmd's Avatar
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    Another thing to look at is prism thinning. Same on all pairs? Trapezoidal and elliptical errors are generally induced by BD prism. Higher the add, the more BD prism.

  5. #5
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    Thanks for everyone's replies. Checked wrap vs old frames and that is higher. I'll also check prism thinning when the patient comes back into practice.

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