This is true. The eyes will tell you what the person is actually feeling. I suppose though, the best actors are the ones that can feel what they want to. Those people are hard for me to read; it takes me longer to understand their character; I have to judge their actions, rather than their emotions - looking at how they understand, relate, treat, and deal with other people. They will generally be poor at those aspects and deal with the resulting social mishaps/problems in a way that pushes people away by objectifying them and raising themselves up, often preferring an intermediary to make a decision on who is in the 'wrong'.
It's weird though, because it's always a lot easier for me to trust someone who is willing to get down and dirty with me because then I know it's possible to connect with their emotions and we can work it out. I know often people claim that going to someone's level is a bad thing, but it's even stranger dealing with someone that presumptuously believes they are on a level above you; at least if someone goes to your level (or vice versa), you can both use that to see eye-to-eye. But it never works when someone is on the pedestal and it's ironic that such a person can then deem themselves more 'mature'. I guess it goes with the psychological dual aspect where one can't be mature, without also being immature. At least, it's true for me.