heugy

hi! very well done! i have this lens and last week i tried to clean it but actually i had a problem: i was in a cleanroom and a drop of ethanol fall on (i really didn't want to wash the lens with ethanol, but the optical paper didn't absorb the solvent at all) and inflitrated behind the front lens, obviously leaving a stain. anybody has an idea on how to remove this stain? thank you in advance! e