The Backside INV coating has begun to crack and separate on my $459 pair of Lenscrafter Progressive Sun Polar Grey tinted glasses purchased from Lens- Crafters. It makes the lens look severely scratched and the view through the lenses is now distorted.
When I visited the store, I was told that I had caused the problem by using mild soap and water to clean them instead of optical quality lens cleaner. That same mild soap and water has never affected my other glasses.
These glasses were great for the first two years and then they suddenly became unbearable to wear.