Appreciate any recommendations for high quality polarized rx lenses. Which manufacturers are better than most etc?
Thank you,
chris
Appreciate any recommendations for high quality polarized rx lenses. Which manufacturers are better than most etc?
Thank you,
chris
KBCo makes a pretty nice polarized lens, as well as Younger.
Big fan of Youngers NuPolar. The brown is as nice as a serengetti.
Chris,
We have Polarview at Excelite. Colors Brown, Gray, G-15 Green.
You can contact me for more information.
David Cormanick
866-889-9776
dcormanick@exceliteinc.com
Polaroid is a sheet that is sandwiched between 2 lenses. They all use the same polarized sheets between their own lenses. They should be all the same.Originally Posted by cdebr8kr
Explanation:
Wide rolls of material run through the process in batches producing the polarised sheet in the different colours and thicknesses that the company makes. The sheet is dyed to different colours, dark grey being the company's and the world's most popular. In addition the company makes as standard colours, medium brown (its second best seller), medium grey, retina-guard (greenish grey), blue glare-guard (a 96 per cent blue light blocker), sportsmen's yellow (brown/yellow), haze fighter, and vermilion. The wide rolls are placed on a slitting machine and slit into rolls of 17in x 400ft, or standard rolls 52mm, 60mm, and 71mm wide to accommodate the various sizes needed for sunglass lenses. International Polarizer also forms wafers in different base curves (i.e., 6.00D, 4.00D.) to be used by the plastic lens casters in making polarised ophthalmic lenses. In this case the wafers are baked out from the polarised sheet and moulded into either a semifinished or finished lens with CR-39 or some other monomer cast around it. In order to explain the process of manufacturing polarised sheet Dick uses the analogy of a plate of spaghetti. The base sheet of plastic that is usually poly vinyl alcohol is like a plate of spaghetti with the molecules all scrambled up. The PVA sheet is then 'stretched', causing the molecules to all line up in parallel like pieces of spaghetti straightened out lying next to each other. Iodine crystals that are poured onto the PVA sheet run down in the channels between the lined up molecules. This creates the polarised sheet that can be thought of as a kind of venetian blind, only allowing the light through in one axis. In mounting sunglass lenses that axis is always mounted along the horizontal or 180° axis. As these facts are better understood and as the quality and variety of polarised lens products available increases, the demand for polarised lenses increases. International Polarizer, as a small company in a small town, is happy to continue to play a leading role in filling that demand.
Chris,
Great explaination to the concept of polarization and the manufacturing process.
It seems everyone understands the benefits of polarization but very few can interpret the physics and mechanical process involved in manufacturing polarized sunwear.
:cheers:
Very much aapreciate the recommendations & the learning of the polar process.
I read where Oakley uses an infusion process versus a conventional process of layering the filters. Is this just marketing spin or does this process actually create better polar lenses?
Chris
Whatever way they are doing it, it will be the same pricinple invented by professor De Land. It is there and can not be changed, maybe the way of manufacturing can be modernized but the effect and final result is still the same.Originally Posted by cdebr8kr
Here is an axcerpt on De Land:
That was just one of a hundred uses for Polaroid plastics. The Polaroids are light filters. Normally, light coming at you vibrates in two directions -- say left-right and up-down. The Polaroids remove light that vibrates in one of the directions.
We knew about polarization 180 years ago. Then around 1930 several things happened. A woman named Helen Maislen studied physics at Smith College. Her professor there coined the term Polaroid. Soon she married Edwin Land, a young physics student who'd been turned on by courses at Norwich College.
Land went on to Harvard. But he got so engrossed with polarization that he dropped out.
In 1937 Land formed a company to produce a new polarizing plastic. Of course he named it Polaroid. By 1943 he was a 34-year-old business wunderkind -- now on vacation in Santa Fe. When he took snapshots of his family, his three-year-old daughter complained, "Why do we have to wait so long to see the pictures?"
Why indeed! That afternoon Land walked through the old town chewing on the question. We shouldn't have to wait. During that walk, he invented the Polaroid Camera in his head.
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