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Thread: prism in progressive lenses

  1. #1
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    prism in progressive lenses

    +0,50 -1.25 90 add. 1.50 8 prisms base out and 1 prism base down
    +0,50 -1.25 90 add. 1.50 8 prisms base out and 1 prism base up

    Can anyone explain why

    1. Rodenstock life 2 is the only design which can be made with these prisms and newer designs ex. multigressiv or impression?
    2. I have to decenter the the glasses horisontally (some millimeters pr. prism), when it is a progressive design, where (in my mind) all prism should be incorporated in the lens?

  2. #2
    Master OptiBoarder OptiBoard Silver Supporter rdcoach5's Avatar
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    Need more info

    The only way this is hard to do is if you're trying to put it into too large a frame. I'm talking about larger than 48 eye and that depends on P.D.

  3. #3
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    If I understand correctly,
    A possible answer to the first question could be that the blanks aren't thick enough. Pick a smaller eyesize.

    I didn't think it was possible to decenter modern progressives to incorporate prism

  4. #4
    Master OptiBoarder lensgrinder's Avatar
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    Quote Originally Posted by thomas pedersen View Post

    Can anyone explain why
    1. Rodenstock life 2 is the only design which can be made with these prisms and newer designs ex. multigressiv or impression?
    2. I have to decenter the the glasses horisontally (some millimeters pr. prism), when it is a progressive design, where (in my mind) all prism should be incorporated in the lens?
    As stated before, question 1 comes down to what size blank you need.
    Question 2 you might want to follow this thread about decentering progressives with a lot of prism. You will measure the prism at the prism reference point which is the point located in between the hidden marks. You can measure what the resultant amount of prims will be at that point which in this case will be 8.06^ @ 187oOD and
    8.06^ @ 7oOS

  5. #5
    OptiBoard Professional Kyle's Avatar
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    This was covered in another post that I'll have to paraphrase. I've looked for the post but can't find it nor do I remember which forum it was posted on.

    Apparently prescribed prism is unavailable for ANY freeform design. From what I vaguely remember it's not a matter of can or cannot but rather a function of whether the software/equipment has been built to perform the task.

    If you know otherwise, let me know. :)

    K

  6. #6
    Allen Weatherby
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    Prism in digitally surfaced or freeform lenses

    Quote Originally Posted by Kyle View Post
    This was covered in another post that I'll have to paraphrase. I've looked for the post but can't find it nor do I remember which forum it was posted on.

    Apparently prescribed prism is unavailable for ANY freeform design. From what I vaguely remember it's not a matter of can or cannot but rather a function of whether the software/equipment has been built to perform the task.

    If you know otherwise, let me know. :)

    K
    I am not sure about other digitally surfaced lens designs and prism but the ICE-TECH Advanced Lens Technologies can deal with prism by design. UP, DOWN, IN, OUT, what ever the Dr. prescribed.

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