After about 5 years, I bought a new pair of glasses. My prescription hadn't changed, but the lenses weren't in optimal condition even though I take very good care of them. The old ones were "OK", IMO, no large scratches but quite a few small "micro" pits. In sunlight the glare was noticeable. They were good for working in the shop and indoors and over time I guess I just got used to them. I tried the new ones outdoors last night and it's a whole new world. Without the light-scattering micro-pits and fine scratches, clarity (resolution) is much improved. I got the anti-reflection coating on these so throughput is much better as well. Contrast is also much better due to the lowered scattering level. My naked-eye astronomy is much improved thanks to clean, new lenses. If you wear glasses, I highly recommend a new pair, and pay the extra bucks for the anti-reflection coating.