Why do many people look at a person's eyes first when judging them? Because to some extent, eye contact is an external window into the brain's state. Among the 12 pairs of human cranial nerves, many are related to the eyes and facial expressions, so a person's emotions, desires, fatigue, and focus often unconsciously reveal themselves through their eyes. Language can be disguised, but the nervous system is hard to fake, so often, the eyes are more honest than the mouth.