I think most everyone will tell you that there is no exact formula for deciding this. That said, it will usually depend on whether if you have full rim frames or rimless frames - full rim or half rim frames will hide most or all of your lens edges very nicely, which in that case, you likely would be fine with even with regular CR-39 (1.498 index) lenses. In the case of rimless frames, CR-39 plastic is too soft for a drill mount application, so you would have to choose a polycarbonate or high-index MR-7 or MR-10, 1.60 or 1.67 lenses.
Your prescription is very mildly common, so unless you are extremely concerned with edge thickness or eye minification, then you will be just fine with nothing higher than 1.61. You will see very little difference in thickness between 1.61 and 1.67 in your correction unless you've got very large lenses (above 55mm) J.Evan On May 27, 6:02 am, angerme <[email protected]> wrote: > I have a prescription of -4.00 should I get the 1.61 index or go all > out for the 1.67? > > would one even notice the difference? --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
