I prefer glass for my daily glasses, they are more abrasion resistant than any plastic. Also glass lens can come in 1.71 index. I would only get plastic if your prescription is above 5 for the reduced weight. Optician recommend plastic probably because it is easier for them to produce and their profit margins are higher, polycarbonate is even softer than CR39, so if impact resistant is not a concern, stick with CR39 or mineral glass.
On Jan 22, 4:35 am, "J. Evan" <[email protected]> wrote: > There has been a lot of controversy created by US opticians about the > supposed 'danger' of mineral glass lenses. In fact, by reading > optician boards you would think glass lenses are more dangerous than > guns - in fact it's much easier to buy a gun than to buy glass > lenses.... but let's not digress. > > What's the story with this fear of the glass lens? Does anyone have > glasses with mineral glass lenses? What's your experience with them? > How do you compare them with your plastic lenses for clarity, weight, > scratch-resistance, etc? > > My second and related question is regarding the magnification effect > of glass lenses for plus prescriptions. I know that the vast majority > of people are myopic and don't have this problem, but I wear about a > +4.50 lens and I have difficulty with the magnification affect, not > only for how the eye looks from the outside, but also what I see > through my lens is magnified. > > Are high-index mineral glass lenses also aspheric? Does the aspheric > shape or magnification have any relation to the level of index - i.e. > does a 1.8 index glass lens magnify more than a 1.9 index glass lens? > > Does anyone have specific experience with this topic or can you point > me to the right sources? > > Thanks --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
