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Thread: High minus lens forms

  1. #1
    What's up? drk's Avatar
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    High minus lens forms

    I thought this was informative

    https://chadwickoptical.com/high-minus-options/

  2. #2
    OptiBoardaholic
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    I like that.

    I use the lens thickness calculator on this site quite often when a pt wants to know the thickness of a lens with a given frame & material:

    http://opticampus.opti.vision/tools/thickness.php

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    Master OptiBoarder DanLiv's Avatar
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    Those are really cool lenses. I wish more digital labs put the effort into custom lenticularization like that. I'm sure it's a PIA to do and disruptive to a high volume production lab. But if it were available from my primary labs, instead of small unknown labs, and in premium lenses, instead of all house product, I would use these types a lot more often. Especially for high minus wrpa frames, I've done a handful through specialty labs and they look amazing.

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    Here are some other cool options.

    http://epiclabsinc.com/

  5. #5
    Rising Star
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    This formula is incomplete as it’s not considering lens final size. Also, percentages often misled.

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    Master OptiBoarder OptiBoard Gold Supporter
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    Dr K this is an awesome tool to teach newbies. Thanks for this!

  7. #7
    What's up? drk's Avatar
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    Ignore that. I'm talking about the lens forms.

  8. #8
    One eye sees, the other feels OptiBoard Silver Supporter
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    Quote Originally Posted by ChrisBowers View Post
    This formula is incomplete as it’s not considering lens final size. Also, percentages often misled.
    It's a rough but valid estimate.

    I understand that the cosmesis is better with the blended surface designs, but I would strongly recommend against using them due to poor tolerance compared to standard lenticulars.
    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.



  9. #9
    What's up? drk's Avatar
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    I've never done a blended lenticular. So...interesting you have that experience. It does seem weird to blend out a ridge. It seems it would cause a blur ring off center. Who knows what it could do to peripheral acuity? But I guess the minification is so much it could be like looking through a sleazy motel door peeper. It's a "field expander" of sorts.

    (Note of interest: in Low Vision Clinic in the days of yore, we would actually have a door peeper to show patients with retinitis pigmentosa. They could hold it up as needed for a quick survey of the scene before walking into an open manhole a la Mr. Magoo. Of course, we never had any real patients.)

  10. #10
    What's up? drk's Avatar
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    Well, while we're on the subject of high minus and edge thickness, I've come up with a couple of rules of thumb (That means: rough. That means: go ahead and argue your case):

    1. If a VISIBLE minus lens edge exceeds 5mm, it's fugly.
    a. that means a plastic eyewire gives you 3-4 mm of bonus
    b. that means a semi-rimless or rimless is working against you
    c. that means a 1-2 mm metal eyewire helps only a pinch. It's the "neutral state".

    2. When doing edge thickness calculations, if the reduction in edge thickness is not greater than a millimeter, it's just not worth it. Two millimeters? Now we're talking.
    a. it may be better to set this rule of thumb up as a percentage, such as "if it's not at least 20% thinner, fugedaboudit", but I haven't tested that theory.

  11. #11
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    Remember, as a general rule of thumb (a few exceptions), thinner lens materials are inferior optically. I always explain this to pts and explain the trade-off. I don't recommend thinner lenses unless there is a 2mm or greater reduction in edge thickness.

    Some pts are hyper focused on thickness so I do whatever makes them happy even if it wouldn't be my personal choice.

    As we all know, frame selection (A measurement, decentration, etc) plays a huge part in the outer edge thickness for high minus.

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    Compulsive Truthteller OptiBoard Gold Supporter Uncle Fester's Avatar
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    Quote Originally Posted by drk View Post
    Well, while we're on the subject of high minus and edge thickness, I've come up with a couple of rules of thumb (That means: rough. That means: go ahead and argue your case):

    1. If a VISIBLE minus lens edge exceeds 5mm, it's fugly. r u fat shaming?
    a. that means a plastic eyewire gives you 3-4 mm of bonus Wear black in layers with a colorful scarf
    b. that means a semi-rimless or rimless is working against you embrace the horror
    c. that means a 1-2 mm metal eyewire helps only a pinch. It's the "neutral state". Spanx

    2. When doing edge thickness calculations, if the reduction in edge thickness is not greater than a millimeter, it's just not worth it. Two millimeters? Now we're talking.
    a. it may be better to set this rule of thumb up as a percentage, such as "if it's not at least 20% thinner, fugedaboudit", but I haven't tested that theory.
    comments in red

  13. #13
    What's up? drk's Avatar
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    Plastic eyewire:






    Rimless:



  14. #14
    Compulsive Truthteller OptiBoard Gold Supporter Uncle Fester's Avatar
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    Her hair at the BET awards was FABULOUS!!!

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    Quote Originally Posted by Robert Martellaro View Post
    It's a rough but valid estimate.

    I understand that the cosmesis is better with the blended surface designs, but I would strongly recommend against using them due to poor tolerance compared to standard lenticulars.
    Seconded (though from your informative posts over the years, this is hardly a surprise!)

    Blended lenticulars are something I have almost always failed to switch existing conventional lenticular wearers into, and I dread the day the labs stop making conventional lenticulars.

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