Eye movements and eye contact provide important social and emotional information. Eye contact, a major channel of nonverbal communication, is the instance when two people look at each other's eyes at the same time; it is the primary nonverbal way of indicating interest, attention and involvement. This includes the duration of eye contact, actions of winking, movements of pupils and eyebrows, and the dilation/constriction of pupils. Generally speaking, the longer there is established eye contact between two people, the greater the intimacy levels. However, the customs and significance of eye contact vary between societies, with religious and social differences often altering its meaning greatly.
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