Wrong. My prescription is -4.25 and I prefer CR39 to the alternatives. I was (OVER) sold on high-index for years. With today's smaller frames, I can certainly buy CR39. For a pair of aviator sunglasses? Sure, those lenses are huge and as they flare out further from the optical center, you're going to get some serious thickness.
I can sit all day working at my laptop without eye fatigue with CR39 in my frames. The polycarb and other hi-index shorten that time considerably. For a script in the -6 range, even -5 I think your point is valid, it's just that the retailers have kept dropping that number to pad their pockets. Much of this boils down to vanity -- and even at -4.25 these frames all look great. If you're concerned about thinkness, pick a plastic frame. They'll "hide" a lot of thickness. At my prescription, there are no physical side-effects from weight of CR39. The skin on my nose doesn't suffer or break down from it. - Ira On May 31, 11:45 pm, clarity <[email protected]> wrote: > I would NEVER use cr39 on a RX over +3.00 or -3.00 unless i HAD TO. > It looks like crap, sorry but like pure crap.It will stick out up to. > 6.7mm i would consider this to be heavy and ugly.Sorry but just > because you want to save money doesnt mean you should buy the cheapest > product available. > Sorry all lenses have abberations, cr39 in one of the most stable > materials in this regard.However, unless you have low vision, or are > unable to be corrected to 6/6 with spectacles you are very unlikley to > notice the difference in abberations if you go for a high index. > > On May 30, 8:52 am, Paul <[email protected]> wrote: > > > -4.00 is not that bad. Personally, except for rimless, I would stick > > with CR39 because of low price, reasonably good thickness, and > > excellent optical quality. > > > If you're getting plastic frames, CR39 is a complete no-brainer. The > > frame will hide any lens thickness, and there's no chance of chromatic > > aberration. CR39 is probably not suitable for rimless for other > > reasons than thickness. I would think that it's fine also for metal > > frames unless you're getting really large ones (50+ mm). > > > Zenni's standard 1.57 "Thin and Light" plastic" (probably the same > > stuff that other places call by that name) should also work fine with > > any frame. --~--~---------~--~----~------------~-------~--~----~ Check us out at the oft-updated http://glassyeyes.blogspot.com! You received this message because you are subscribed to the Google Groups "GlassyEyes" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/glassyeyes?hl=en -~----------~----~----~----~------~----~------~--~---
