Most Helpful Guy
Well, eye movement is coupled with sincerity and honesty, they twitch this way and that way depending on which part of the brain you're activating, sometimes enough that head movement follows. Rapid eye movement is also a sign of nervosity, which can be contributed to dishonesty too. The level of pupil dilation is also indicative of a lot of things, including attraction, stress and pain. In addition, many of the muscles around the eyes are used to convey emotion and intent, for example movement of the eyebrows.
Books are written in volumes on the issue of eyes betraying the intent and emotion of a person, and these are just a few obvious examples off the top of my head. The vast majority of these signs are interpreted subconsciously, meaning eye contact is the most useful tool when it comes to reading body language, both with intent, and subliminally.