Eyebuydirect.com offers CR-39, and they specify the correct refractive index. I bought two pairs and they seem optically very good to me.
Globaleyeglasses.com also claims to offer CR-39, but they do not specifically list the index. Because they also offer a 1.56 lens, I infer that the CR-39 might be the real deal, but it is dangerous to assume. I haven't tried them yet. The "CR-39" offered by goggles4u.com and optical4less.com is obviously not true CR-39. I did order a couple of pairs from optical4less, and the lens material is obviously inferior to CR-39 with respect to clarity and chromatic aberration (but far, far better than polycarbonate). Also, the a/r coating was poorly applied (streaky) on my o4l glasses. Maybe I'll change my opinion as I get older and my glasses get thicker, but I don't understand why most people like high-index lenses so much. I think the optical quality is questionable (terrible, in the case of polycarbonate), and would rather have thick glasses and good vision than thin glasses and poor vision. On a related note, do any bargain online places offer crown glass? I can only find high-index glass, such as the 1.56 index mineral glass at goggles4u, and I'm guessing that isn't much different than the 1.56 plastic. On Mar 1, 12:12 am, Reid Priedhorsky <[email protected]> wrote: > The online research seems to indicate that what I want is very basic: > CR-39 lenses, low refractive index, with anti-reflective coating. > Where can I get this? And how do I know what I'm getting? > > Of the vendors mentioned on the blog, 39dollareyeglasses smells the > best to me, but they don't seem to offer plain single-vision CR-39, > just in sunglasses or bifocals. Goggles4u offers CR-39 but in a > refractive index of 1.56, which seems to have an Abbe number not much > better than polycarbonate. --~--~---------~--~----~------------~-------~--~----~ Check us out at the oft-updated http://www.glassyeyes.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 -~----------~----~----~----~------~----~------~--~---
