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Thread: CR-39 vs 1.6 weight in very low powers?

  1. #26
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    Quote Originally Posted by drk View Post
    Yeah, but how much are we talking?

    One gram = one paperclip. Balance a paperclip on the front of your glasses and tell me how your nose hurts.


    Dang it, I almost poked my eye out!
    I'll be the nit picker. I have a triple beam balance scale...very, very accurate. One regular size paperclip weighs 1/2 gram. A little more if there are any eyelashes attached.

  2. #27
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    Sounds like optiboard has turned into a Monty Python sketch.


  3. #28
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    What is the minimum center/edge thickness for full rim frames? If it's 2mm, then 1.6 lenses in plano or low plus powers would probably not be any lighter. I have a pair with round 1.6 lenses (+0.25) which should weigh no more than 4 grams each according to the Spectacle Optics program, but they actually weigh 5 grams each. Seems pretty pointless then. If only I could order Trivex...
    Last edited by Airegin; 06-18-2020 at 07:59 PM.

  4. #29
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    Quote Originally Posted by drk View Post
    Yeah, but how much are we talking?

    One gram = one paperclip. Balance a paperclip on the front of your glasses and tell me how your nose hurts.


    Dang it, I almost poked my eye out!
    Ever had a patient bring their own scale and weigh glasses on it as they are trying them on? I have.

    I wanted to smash that scale after about 20 minutes.

  5. #30
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    Quote Originally Posted by Tallboy View Post
    Ever had a patient bring their own scale and weigh glasses on it as they are trying them on? I have.

    I wanted to smash that scale after about 20 minutes.
    Sick Really Sick. You can't make this stuff up! We definitely need a psych degree to do this job! I have a minor in psych... that's not enough.

  6. #31
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    I had created a sample page to show the differences in weight, thickness and chromatic aberrations a while back.
    I titled it The War between Optics and Cosmetics, after Barry wrote his article in 20/20
    It breaks everything down in charts.
    You can view it here.

    https://www.mccardle.me/analysis/

  7. #32
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    Interesting thread.
    I have thought that it's time the optical industry move on and dropped Cr39 and use 1.6 as the standard lens material. Uncoated it is not too reflective if no MAR is issued.
    It would, however, need top down cost revisions from manufacturers through to labs to get the cost similar to CR39.

  8. #33
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    Quote Originally Posted by goonybird View Post
    Interesting thread.
    I have thought that it's time the optical industry move on and dropped Cr39 and use 1.6 as the standard lens material. Uncoated it is not too reflective if no MAR is issued.
    It would, however, need top down cost revisions from manufacturers through to labs to get the cost similar to CR39.
    Let's get rid of a great, inexpensive material that is suitable for many patients? What on earth for?

  9. #34
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    Brent, nice!

  10. #35
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    Quote Originally Posted by Don Gilman View Post
    I'll be the nit picker. I have a triple beam balance scale...very, very accurate. One regular size paperclip weighs 1/2 gram. A little more if there are any eyelashes attached.
    https://www.google.com/search?q=weig...hrome&ie=UTF-8

    Liar! Heretic! Psycho-killer of truth!

  11. #36
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    Quote Originally Posted by Kwill212 View Post
    Let's get rid of a great, inexpensive material that is suitable for many patients? What on earth for?
    UV Absorption, Toughness, Thinner on higher Rx's need I go on. Days of CR39 are numbered.

    This a old style landline telephone compared to latest iphone

  12. #37
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    Quote Originally Posted by goonybird View Post
    UV Absorption, Toughness, Thinner on higher Rx's need I go on. Days of CR39 are numbered.


    Yes, you do need to go on. You seem to be implying that I said 1.60 was no good and we shouldn't use it. I obviously didn't. You compared 1.60 to CR39. I asked why would we get rid of a great, inexpensive material that is suitable for many patients?

    Quote Originally Posted by goonybird View Post
    This a old style landline telephone compared to latest iphone
    Not even close to a comparison that makes sense.

  13. #38
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    Quote Originally Posted by goonybird View Post
    UV Absorption, Toughness, Thinner on higher Rx's need I go on. Days of CR39 are numbered.

    This a old style landline telephone compared to latest iphone
    CR-39 remains better with no AR. Then again I don't see why AR and scratch resistance shouldn't be standard either. How much more does AR add to manufacturing cost anyway?

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