don't rub the inside lense if it's wet, it's said on the box and in the "manual"
if the coating is damaged, you can use an anti fog spray/solution to restore it, but you'll need to apply it regularly ....
also the scuba diver idea really works
although spitting is perhaps a bit harsh, but if you really have terrible fogging inside, and you need an instant solution in order to save your day, you could wet your fingers with a bit of saliva and gently wet the inside of the lense ....
(just make sure you didn't eat some chocolate or something right before doing it ..
Belgium represent !
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