I tried just exactly that last week on a cheap pair of reading glasses with full strength Future and a Q-Tip. Didn't work. Just left a big smear of Future on the lense.
I still think that's what it is, though probably in a diltued form. However........Watch closely at the Mom "de-scratching" the little girl's glasses. When she does the final sweep over the lense and holds them up, I swear I can see some smearing (just the way mine looked).
I think I'll just keep my nice Serengeti's in their nice little clamshell case. And stick with a good cleaning cloth for when I do wear them.