Thanks, J. Evan and Firewalker for great information. That's what I love about this site, the NO BS info that you all provide. I went to a store to find out how much relensing would cost for my rimless and they wanted $300 for polycarbs with all the works. Little did they know that I have the power of Glassyeyes on my side. Thanks again.
On Jun 7, 8:30 am, "J. Evan" <[email protected]> wrote: > You might be confusing CR-39 plastic lenses with other MR type plastic > lenses. CR-39 only comes in an index of 1.498, however many lens > manufacturers produce lenses they might call CR-39 that can have > slightly different indices. I can be easily argued that the difference > between 1.498, 1.5 and 1.56 index lenses will be indescernable - the > lens size, shape and lab work will be much larger factors. > > Now, to your question about drill mounting CR-39; there seems to be > conflicting opinions on this within the dispensing industry. Some say > that CR-39 will crack or chip if drill mounted, others have said that > they've drill-mounted CR-39 for years with few problems. There seems > to be a conflict here with 'newer' polycarbonate lens propaganda > clashing with more 'traditional' CR-39 lens history, with the trend > moving everyone to the newer and more expensive option. For example, > our local Lens Crafters refuses to do drill mount frames with anything > but Poly - and their dispensers gasp if you mention anything else. > It's what they've been told is the only option and they scare their > customers into believing that their eyes might be at risk unless they > pay for Poly. > > I would conclude with this; 1. Don't be worried that your CR-39 lenses > are more likely to shatter than polycarbonate - they're both very > highly impact resistant. 2. If you are happy with your current lenses, > you should stick with them, especially if they're inexpensive. 3. > Understand that there are always newer materials out there, like > Trivex, which by comparison is lighter and stronger than CR-39, but > it's also more expensive - you can experiment with other options if > you choose. > > J. Evan > > On Jun 4, 9:38 pm, TujuMaster <[email protected]> wrote: > > > > > I hope this has not been asked before but I searched the group and > > found nothing on this. I was talking to a friend of mine and he says > > Polycarb lenses should always be put in rimless and semi-rimless > > glasses. Since I started wearing glasses six months ago, I purchased > > two pairs of rimless specs, one with CR39 1.5 index and CR39 1.56 > > index, and a pair of semi-rimless CR39 with 1.5 index. Is CR39 not > > recommended for these types? Does it shatter to easily? I've never > > had an issue with CR39 and I'm pretty rough on my specs. Your help is > > greatly appreciated. --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
