I came across this board quite by accident while researching options for my new glasses, and since you appear to be a smart bunch, maybe someone can satisfy my curiosity :)
I've been wearing a set of Transitions Crizal for the last 3 years, and have been relatively happy with them. I have however noticed what appears to be a very fine grid of hairline "cracks" when the lens is viewed from the back - and these have progressively worsened as the lenses aged.
My guess is that these are microfine cracks in the AR coating because of heat expansion of the lens material, but this is obviously just a guess...
Does this happen to Crizal coatings (or any AR coatings for that matter) when exposed to heat? Could the heat from e.g. a BBQ cause this to happen or from washing under too-warm water?
I'm considering getting similar lenses for my new spectacles and would therefore like to know what caused this and if it is because of misuse (e.g. can be avoided) or simply because of old age.
Thanks a stack!