Eye Contact
Eye contact is looking at someone's eyes during a talk to show you are paying attention.
Think of it this way
Two cups sit on a table. One cup faces the other, their openings lined up. That direct line shows a clear, open path between them. When a cup turns away, the path breaks.
Explaining eye contact by grade level
When you look at a friend's eyes while you talk, they know you are listening. Try it: ask someone a question and look at their eyes. Now try looking away. Most people can tell when you stop watching them.
