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Thread: 1.74 vs 1.76 double aspheric lenses

  1. #1
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    1.74 vs 1.76 double aspheric lenses

    Hello, new member here
    Im currently dealing with the following big prescription: -16 on one eye, and -18 on the other.

    What would be the approximate size difference, in terms of thickness of the lens at the edges, between 1.74 double aspheric lenses and 1.76, if any at all?
    Are 1.76 lenses worth the extra price investment?
    Btw, the chosen frame has a lens diameter of 47mm

    Thanks!

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    Underemployed Genius Jacqui's Avatar
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    I don't think you will see much difference if any. This is not from calculations, but from experience.

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    Try this

    How about some contact lenses first and then glasses on top? Help them out! LASIK?

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    1.76? Am I missing something? Is this a Canadian material. I have not seen it. Guess I better get on the research boat now!

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    Underemployed Genius Jacqui's Avatar
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    Quote Originally Posted by EyeCare Rich View Post
    1.76? Am I missing something? Is this a Canadian material. I have not seen it. Guess I better get on the research boat now!
    It's made by Tokai in Japan, not seen much here for some reason.

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    Master OptiBoarder optical24/7's Avatar
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    Last I heard it didn't pass our drop ball test required here in the U.S.

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    Quote Originally Posted by Jacqui View Post
    It's made by Tokai in Japan, not seen much here for some reason.
    The problem is that coating on 1.76 is not index matched, although they are working on it. There is an enormous amount of bi-refrigence in the 1.76 samples I have. They did pass a drop ball test in the lab, though. I measured a 1.74 and 1.76 in a -12.00 and thickness difference was insignificant.
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    Generally, a bi-concave lens is thinner over a -14.50, however, the front side cosmetics are strange.

    I would contact Ice-Tech. We did a 1.74 -24.00 in a 49 eye that finished out with an 8.4 mm edge thickness. It looked amazing. They use a patented thinning process, on special modified generators, with software they wrote from scratch, on blanks they make in-house.

    Quote Originally Posted by hervens View Post
    Hello, new member here
    Im currently dealing with the following big prescription: -16 on one eye, and -18 on the other.

    What would be the approximate size difference, in terms of thickness of the lens at the edges, between 1.74 double aspheric lenses and 1.76, if any at all?
    Are 1.76 lenses worth the extra price investment?
    Btw, the chosen frame has a lens diameter of 47mm

    Thanks!
    Beer is proof that God loves us and wants us to be happy ~Benjamin Franklin

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    Hi Guys, I couldn't help but notice this thread. The cataloged edge thickness of the Nikon 1.74 DAS for a -17 with a 60mm blank is 13.9mm and the cataloged edge thickness of the Tokai 1.76GO is 11.4mm also with a 60mm blank. I hope this helps.

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