I'm currently wearing a pair of glasses that are 5 years old with Crizal lenses. I've had them on my last couple of sets of glasses, and have been quite happy.
In any case, at my two-year eye appointment after buying the current pair I'm wearing, the doctor advised me that I had a small enough change in my prescription that I didn't really NEED new glasses. Instead, I opted to cash in on the 2-year warranty and got a fresh pair of Crizal lenses(same presecription) that I'm still wearing.
Hopefully later today, I'll be picking up a new pair that are virtual carbon copies of my current pair except with my most current prescription(from about a month ago). They're in the same frame model number(since I've been very happy with the current ones) and have whatever the current Crizal coating is. It would be nice if I got another 4-5 years out of them, although even two is great.
I had no coating on the lenses right before my first Crizal set, and I was virtually blind in night driving(to the point where I avoided it) with those due to the extreme internal reflections in my left coke-bottle lens. A combination of higher index lens material with a good AR coating(Crizal just because that's what the optician I use sells) has helped my night driving vision be as good as my day vision.
BTW, I've had great luck cleaning with a DRY cotton t-shirt. Ideally you want no fabric softener, but even one with softener will do the job. If mine get dirty during the day, I've been known to just use the tail of my undershirt to do a quick clean-up.
