When making eye contact, which eye do you look at?

This drives me absolutely INSANE. If I’m not -thinking- about eye contact, it seems to come naturally. But go have a conversation with the person nearest to you and really think about how eye contact works. For your eyes to look at something, they have to focus on the same thing. So which eye are you looking at since reasonably you can’t look at both? Suddenly you’ll find yourself trying to choose an eye and the person will ask if they have something on their face and the confusion now spreads. HELP. I CANT STOP THINKING ABOUT WHICH EYE AND BEING AWKWARD