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Progressive with high prism

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    #16
    There is no free form generator that can handle that amount of prism. Actually they have problems with more than 2 diop of prism. Usually you have to block in the prism and not ask the generator to produce it when above 2. If you want to be creative and actually have a blank thick enough to accommodate this amount of prism it could be done by first grinding the progressive design on the back of the lens and then grinding the prism on the front. Most labs do not have the tooling or equipment to process convex curves but some do and this could be done.

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      #17
      Oi, the research is sound and in a real world application it absolutely works. I work for a lab - if we did it automatically there would be nothing but remakes. I have accounts that are aware and use the concept. The vast majority would consider it a lab error.

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        #18
        I know. Patient was wearing 8 base out OU successfully in a progressive. We have a lab that can do in in 1.74, but the patient would need to go to a 48-50 eye size frame. Patient has a large face/head and that frame size is way too small. I'm working with the prescribing doctor to see of we can come up with a solution that will make both the patient and doctor happy.

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          #19
          Patient currently wears 8 Out OU for a total of 16.

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            #20
            Originally posted by Jalane View Post
            I know. Patient was wearing 8 base out OU successfully in a progressive. We have a lab that can do in in 1.74, but the patient would need to go to a 48-50 eye size frame. Patient has a large face/head and that frame size is way too small. I'm working with the prescribing doctor to see of we can come up with a solution that will make both the patient and doctor happy.

            Hate to say it- but Oakey works wonder for finding a smaller eye size (51ish) with accommodating for a wide fit. The bowing in the temples has been a life saver for me with certain fathead/ high Rx combos.

            Ovvo is a great line for a small eye size but stretchy fit. The lens will always be much more visible though. (I did a -20.00 years ago that worked out well.)

            Please post a photo of the outcome if you can. I'm sure many on here would be intrigued with that amount of prism. I don't think I've seen anything over their original strength of around 16 total.
            Have I told you today how much I hate poly?

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              #21
              Originally posted by Jalane View Post
              I know. Patient was wearing 8 base out OU successfully in a progressive. We have a lab that can do in in 1.74, but the patient would need to go to a 48-50 eye size frame. Patient has a large face/head and that frame size is way too small. I'm working with the prescribing doctor to see of we can come up with a solution that will make both the patient and doctor happy.
              Jalane
              26 total prism. 13 out in each eye.
              Two points: 1) The wearer will lose two to three lines of VA with low abbe materials, about the same they would experience with a Fresnel, except with the latter they will only lose VA in one eye. 2) If a PAL, you'll need to increase the decentration by about 3mm per eye. Make sure your lab knows this because a smaller eye size will probably required, depending on the dioptric power, probably in the 42mm to 44mm range, or use lenticularization.

              Best regards,

              Robert Martellaro
              Last edited by Robert Martellaro; 05-18-2021, 06:35 AM.
              Science is a way of trying not to fool yourself. - Richard P. Feynman

              Experience is the hardest teacher. She gives the test before the lesson.


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                #22
                I'd be really tempted to make a simple sv distance rx into her frame at cost (or roll it into the charges) to be sure this complicated expensive job for her doesn't turn into an expensive complicated job for me too.

                Trial frames and real world frames & lenses are usually the way to go, but this has red flags flying!!!
                Last edited by Uncle Fester; 05-19-2021, 06:50 AM.

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                  #23
                  I agree about the red flags! I discussed going to SV distance and readers, but she really is adamant about keeping her progressive.

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                    #24
                    Stay tuned......

                    After speaking with the prescribing doctor, we are going to try lenses without any prism to see if she can adapt to the esotropia with suppression scotoma. If she cannot adapt, its back to the drawing board.:unsure:

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                      #25
                      Is strabismus surgery an option for the patient?

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                        #26
                        Strabismus surgery not an option.

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                          #27
                          Strabismus surgery is not an option for this patient.

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                            #28
                            Update on Progressive with High Prism

                            Patient picked up her new glasses without any prism. The diplopia is still present, but not as pronounced as we thought it might be. She tolerates it better with her polarized sunglasses than with the clear lenses. She is being referred to a neuro-ophthalmologist by her regular ophthalmologist.

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                              #29
                              Thanks for the follow up.

                              Will your Doc still be in the communication loop?

                              If possible it would be great to hear what the top dog recommends.

                              Kind regards,
                              Fester

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                                #30
                                Yes, the original doc will still be in the loop. I will post further updates as I receive them.

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