Hello:
I'm a retired optical engineer, but am still having a hard time obtaining information on the following. If anyone has a spare few minutes, would be most appreciative for any wisdom on the following:
I have significant retinal problems in both eyes, so am really concerned about UV protection.
a. My first question concerns CR-39 for the polarized, single vision, prescription, sunglasses I wish to order:
Is the clear catalytic dye used to extend the UV A and UV B absorptions to
approx. 400nm "usually" added to the monomer when they make the plastic
sheets, or is it just a surface coating on the front or rear surface (or I guess another possibility might be inside the sandwich where the polarized sheet is located)?
b. Do ordered lenses automatically come this way with the UV protection(s)?
c. Can I safely assume that any prescription sunglasses I order will be
CR-39 or polycarbonate, and not acrylic?
d. Same question as (a) for Polycarbonate and/or Glass lenses.
e. Is it worth it in your opinion trying to find someone to make them out
of Polycarbonate for me rather than CR-39(for their UV protection, if truly better)?
f. Or, in Glass? (is there any/much UV A and UV B protection inherent in
the basic glass usually used?)
g. Any strong pro and con opinions on the Photochromic type of lenses?
Do they work well in cars?
I am asking as I believe they work on UV, and the cars glass would cut out a significant amount of UV, I would think?
It seems they also come now in plastic (I'm not sure which) and glass.
Particularly wondering about the UV A and UV B protection they afford?
Unofficially, are the Maui Jims and Action Optics worth the very high $$$ costs, in your opinion?
I guess you are paying for the A/R and hydrophobic coatings. Is the A/R worth getting; do they scratch or come off easily; I think they are on the surfaces, not inside the sandwich.
What brand lenses would you suggest I order, with my retinal problem concers?
Much thanks; appreciate your time.
Bob rgsrose@tiac.net
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