Eyes give off many social cues. What are some key cues provided by the eyes in social interaction?

One key cue provided by eyes is mutual gaze, which signals that the attention of both individuals is directed to each other. Gaze following is another key cue, where one person's gaze 'follows' the gaze of the other person, directing attention to the gazed-upon item or person. Related to gaze following is shared attention, where both persons focus their attention on a third object or person as well as on each other.