I cant remember the name of a film that had something to do with masks, can anyone help?

I was shown it when i was young so it could be any time during or before the 90's. I remember it had something to do with masks of power but the only thing i distinctively remember is a microscope that when focussed stabbed knives in the users eyes and said the word 'liar'. It may have had a zoo at the start but i dont remember, if anyone knows this film please say.