You can have full conversations with your best friend only using your eyes, when you are surrounded by too many people who can't know things you need to communicate. You can use your eyes to apologize to someone, to share a smile with someone, to express desperation, to express horror and anger and to show desire for something or best of all to roll them at someone too basic.
Then there is the greatest of all use of eyes, as shown perfectly in this song up to a minute and twenty seconds, when you are searching for the most elusive of all emotions. I look at you, you look up, I look away. I look up and catch you looking at me and still I look away. This little dance of peeks and glances, and I hope you are braver than me. We look at each other a little too long and know we aren't just friends anymore. You almost begin to recover and then they look at you again.
Sometimes you look at me, when I'm not looking but aware that you are. I pretend like I don't know but trying to stop turning the brightest shade of red under your watchful glance. Eye contact is how souls catch fire. You can never forget the moment when your eyes first meet, the trivial moment of nothing, yet the beginning of everything.