Hi guys
I have had the medical requirement to where reading correction for a couple of years now. What I can add to this discussion is;
CASA require two pairs on deck, there are no restrictions on tinting so one can be sunnies.
I use graduated lenses and they take time to get used to, your brain has to learn how to read the signals from your eyes and it can be quite uncomfortable. Some people may never adapt and as such bi-focal may be your only choice.
Wrap around lenses will need to be of the highest quality to help reduce distortion at the peripherals. I have wrap around sunnies, to reduce light coming in from the sides, but not in my clear lenses that I wear at night. You can get some weird effects off these things especially at night.
If you want the clearest vision, do not buy polycarbonate lenses, you will need to use TRIVEX, CR39 or better still GLASS. You will need to go to one of the better quality outlets to get these. Believe it or not two of this countries most prominent and well regarded eyeglass suppliers do not supply the best stuff. The injection moulding process of polycarbonate lenses puts stress into the product basically distorts the vision and can create a slight milky look.
My sunglass lenses are made from TRIVEX (index 1.53) and have all the properties of polycarbonate however they have have a much better ABBE value of 45 Vs 29, i.e. they are virtually as clear as glass. CR39 is another option for good clarity but it may shatter if thrown at the concrete at high velocity. Glass will definitely shatter on contact with the hard stuff but is the best when it comes to scratch resistance.
About Trivex
http://www.x-celoptical.com/aris_tri...chFeatures.pdf
Serengeti sell prescription lenses in TRIVEX but you need to go to a Serengeti agent, and there are surprisingly few, and be sure to ask for genuine serengeti lenses. They are expensive, not much change from 1K! You can get TRIVEX from other good suppliers but when I worked it out the price was not much different, perhaps $100 cheaper with decent frames. I went for the serengeti, figured I wear then all day and want the best sun protection for my eyes and apparently the lenses are adapted best for the wrap around frames.
Choose AMBER, brown or if your completely obsessive about colour, grey lenses.
I can't believe they are not a TAX deduction for at least the sec on pair???
SN