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    Prism trouble shooting question

    I'm trying to pick some brains for help on troubleshooting my new Rx.

    I just received my new glasses from my job (SVS vision) and I have having some difficulty adjusting to my new Rx. And we are scratching our heads with the troubleshooting.

    Old Rx
    OD -0.25-0.25x 70 2BI ADD 1.00
    OS -0.25-0.25x 120 2BI ADD 1.00 Polycarb + AR

    New Rx
    OD -0.25-0.25x 70 4BI ADD 1.25
    OS -0.25-0.25X120 4BI ADD 1.25 high index 1.67 +AR

    my Old Rx mono PDs of 32,32 which we used on my new pair due to not having any problems on previous 2 PALs. However while trouble shooting pupilometers measure me at 33.4,34.5.

    Lensometer checks out, Seg heights check out, and Good fit (drilled rimless frame if that matters) But I am getting a really noticeable 3D effect, particularly with Blue Lights (LEDs etc), I've had this effect with reds for over a year now and just got used to it that I ignore it, But with these blue lights its really throwing me off. Also my distance is not as clear, I actually feel like like I am wearing a plus lens but lensometer reads ok. No headaches or pulling that I am aware of. it actually feels quite comfortable

    Unfortunately the suits upstairs are kinda anal when it comes to employee remakes so we cant do too many of the "well let's try this and see how it works"

    Any ideas ???

    #2
    Four more prism diopters is a lot. Why?

    Comment


      #3
      Eyes drift outward and I was getting headaches without the prism, when I look at things out in the distance objects go in and out of focus. I guess I liked it in the chair when he upped it from 2 to 4 but in my actual glasses I'm struggling with it. It feels comfortable for the most part but visually the I'm struggling with the 3d effect from lights and distance is not as sharp

      Comment


        #4
        Probably caused by chromatic aberration. Because the prism is prescribed, the aberration shows up in the straight ahead gaze as well as the lateral gaze. Switching to a higher Abbe value lens material, Trivex or 1.60 for example, will reduce the symptoms.



        Hope this helps,

        Robert Martellaro
        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.


        Comment


          #5
          Why 1.67? Makes no sense(neither does poly for this). Low abbe value is the obvious problem here as Robert said.


          Might want fix your PD while you are at it. If your PD is really 68 and your making them at 64 you are neutering the corridor. Might not be terrible now with a low add, but it's going to get worse as your add goes up. Also you should be moving the PDs out to compensate for the base in prism. So if your PD is 68 you should really be pushing the PD out to 70.5.

          Also what symptoms were you experiencing necessitating the jump in prism?

          Comment


            #6
            Originally posted by Kwill212 View Post
            Why 1.67? Makes no sense(neither does poly for this). Low abbe value is the obvious problem here as Robert said.


            Might want fix your PD while you are at it. If your PD is really 68 and your making them at 64 you are neutering the corridor. Might not be terrible now with a low add, but it's going to get worse as your add goes up. Also you should be moving the PDs out to compensate for the base in prism. So if your PD is 68 you should really be pushing the PD out to 70.5.

            Also what symptoms were you experiencing necessitating the jump in prism?
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            Comment


              #7
              Hey, Kwill:

              On that prism thing, do YOU do it, or does the lab do it? I.e., how do you safeguard against "double compensation"?

              Comment


                #8
                I don't know of any lab that would do this on their own. You order a the adjusted PD.

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                  #9
                  chromatic aberration. why are you in 1.67? I'd go straight up CR-39 and back the prism off 1D in each eye

                  Comment


                    #10
                    It's a drilled rimless frame, the doctor bumped the prism up from 2 to 4 in the chair and it felt fine in the trial frame

                    Comment


                      #11
                      Originally posted by hrivas302 View Post
                      It's a drilled rimless frame, the doctor bumped the prism up from 2 to 4 in the chair and it felt fine in the trial frame
                      switch to trivex. I'd still lower the prism. may have some aberration still but will definitely be improved

                      Comment


                        #12
                        I went with 1.67 due to my manager and coworkers recommendation. It's a drilled rimless frame ( I know not the best choice), I wasn't complaining to much just a little fatigue when reading at distance and near. Doc bumped it up and it felt fine while I was in the chair

                        Comment


                          #13
                          Originally posted by chamilun View Post
                          switch to trivex. I'd still lower the prism. may have some aberration still but will definitely be improved
                          You'd lower the prism without any patient history, or exam? Sound doctoring there.

                          Comment


                            #14
                            Originally posted by hrivas302 View Post
                            I went with 1.67 due to my manager and coworkers recommendation. It's a drilled rimless frame ( I know not the best choice), I wasn't complaining to much just a little fatigue when reading at distance and near. Doc bumped it up and it felt fine while I was in the chair

                            So this is Vision Works? America's Best? Somewhere that the manager trained all the employees and the manager doesn't have any ophthalmic optics training.

                            Comment


                              #15
                              Originally posted by Kwill212 View Post
                              You'd lower the prism without any patient history, or exam? Sound doctoring there.
                              yes. starting to see your personality. you canhelp, or move on. your choice

                              Comment

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