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Ultimate Clarity in a Set of Eyeglass—No Longer Soldwith the system.
Topic Rating: 5 Topic Rating: 5 Topic Rating: 5 Topic Rating: 5 Topic Rating: 5 Topic Rating: 5 (1 votes) 
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Irv
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December 18, 2018 - 6:28 pm
Member Since: December 23, 2017
Forum Posts: 1130
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I often joke that any technology that I enjoy is doomed to failure.  A case in point.

A little known fact is that an astronaut slowly loses visual acuity due to the bulge in the eye ball from lack of gravity.  NASA sponsored the development of eyeglasses that did not require lense grinding.  

I had worn bi focal eyeglasses for years and found them limiting.  I often had to observe mechanical systems overhead, which was not possible with current eyeglass technology.  My son, a Physical Therapist, said that falls due to bi focal caused distance misjudgment was a major cause of broken bones in the elderly.  So I became an early adopter of the Tru Focus brand of eyeglasses.

My glasses had a ground front lense due to astigmatism, held in place with small magnets.  The main lense was a circular gell sack that was stretched by a mechanical linkage.  The lenses could create focus from a few inches to infinity.  It was possible to adjust the focus at the top, middle, and bottom of a page of print.  Dust removal was an issue.  Wonderful technology that lacked a market.

A lower cost version is now being used to provide glasses to the world’s developing countries.  A syringe supplies gell to the lense, and is snapped off to cause a seal when corrected vision is obtained.1BAA0C46-2EFC-4B49-B71C-80F389CA0938.jpegImage Enlarger

Research is what I’m doing when I don’t know what I’m doing.  —Werner von Braun

Without deviation from the norm, progress is not possible.         —Frank Zappa

Experience is a difficult teacher, it gives the test first and the lesson after.

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Gordon Shumway
London, England
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December 20, 2018 - 4:29 am
Member Since: August 1, 2016
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I wore varifocals for two years. Bifocals are infinitely better, unless, I imagine, you have a very specific prescriptional need.

Being short-sighted (also astigmatic, fwiw), thus having a distance prescription which makes it impossible for me to see music on a stand, I buy clip-on flip-up reading glasses for reading music.

I haven't used my mirror compass for many years!

Andrew

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Irv
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December 20, 2018 - 9:54 am
Member Since: December 23, 2017
Forum Posts: 1130
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I also tried the varifocals.  When I switched to the Tru Focals and had to step over a mount of dirt, I can remember placing a foot forward like a horse several times.  My brain could not commit to the step because it could not determine where the ground began.

I am also near sighted.  After the gell ran out of my last set of Tru Focals, I experimented with various focal lengths of inexpensive foreign made eyeglasses.  I now read unaided and use a computer length set of glasses as my daily set.  I only use my distance set for lectures and theater.  I would go back to the Tru Focals if offered again in a second.

Research is what I’m doing when I don’t know what I’m doing.  —Werner von Braun

Without deviation from the norm, progress is not possible.         —Frank Zappa

Experience is a difficult teacher, it gives the test first and the lesson after.

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