Many books have been written on body language, and in particular, eye contact. Generally in the Americas and in much of Europe, making eye contact with another indicates that you are listening and interested in what the other person has to say. When you look away, it implies that you are not paying attention, are uninterested, or disagree with what the other person has to say.
Your DISC tendencies may play a role in how you use eye contact. When a disagreeable comment is made to a D (dominator), the D may look at the speaker with a stern, forceful look. The look says, "I hear you, and I do not agree with what you are saying."
When a C (critical thinker) hears a disagreeable comment, the C may tend to look down or away from the speaker, hoping it will cause the speaker to stop talking.
In the same scenario with an S (supporter), the S is likely to make eye contact with raised eyebrows, exposing negative feelings regarding the comment.
Although those who have a high degree of I (influencer) tend to use eye contact a lot, when listening to another person speak, the I is most likely thinking, "Why is this person speaking? I want to be speaking. How can I capture control of this conversation?"
A lot can be stated nonverbally through effective use of eye contact. A person who maintains eye contact can maintain control of an interaction, especially when the other person looks away.
Overuse or abuse of eye contact could make others uncomfortable, especially if there are possible relationship implications. In some Muslim cultures, for example, eye contact between males and females is frowned upon. In any culture, there is a tipping point between a gaze that indicates sincere interest and a gaze that indicates, "I'm feigning interest." Eye contact when combined with variations of other facial expressions—raised eyebrows, smile/frown, and so on can take on completely different meanings.