I don't have actual figures. But what it means to the consummer is that the optical qualities won't degrade over time nearly as quickly even from the best of care.
It isn't generally known, or even accepted, but every time you clean a lense, you put tiny, invisible to eye scratches in the soft coatings. Over time a binocular, or a rifle scope, will loose some of it's ability to transmit it's image and suffer from a loss of resolution as well. E
