It has to do with your eyes. >> If I'm crying? >> She keeps telling the officers the same thing. Her eyes are red because she has been crying all day. And honestly, that sounds reasonable. But the officer is not looking at how red her eyes are. He is watching how they move. There is a roadside test that looks for an involuntary jerking of the eye that shows up when someone has alcohol in their system. You cannot cry your way into it. And you cannot fake your way out of it because you do not control it. That is the whole point. When he tells her the eyes do not lie, this is what he means. Crying makes your eyes wet. It does not make them jerk. So while she is busy explaining the tears, the test has already told him what he needs to know. Would you have known the difference? Let us know below.