If you want to psych someone out, look at her or him fixedly.

If you are trying to find out some important information from the conversation but feel that one is evading the truth, then keep a straight eye contact until she or he reveals all the cards. Eye gazing is a subtle psychological trick that is a veiled form of attack. Staring into one's eyes during the conversation, you challenge him/her in some way. So, the victim subconsciously experiences fear and understands that in order to overcome it, she or he needs to tell the truth.