I've been using mine daily for about a month... perspiring quite a fair bit, and i've yet to see any fading of the words on my pair? I've run my finger nails across the wordings and found them to feel suspiciously like they were engraved rather than painted on? The letters don't pop out like I expected paintings to be hmm... Bought mine from Japan just last month~
I've only been wiping them down like once or twice a week, usually if I've been perspiring too profusely. Otherwise, I don't baby them overly, nor do I abuse them... And just to clarify, my perspiration's pretty corrosive, having worn down 3 pairs of Oakley spectacles where the arms touch my ears in the past couple of years~
Have you been rubbing on your pair trying to get a genie to appear?