When we want to communicate anything important we tend to look each other in the eye. Conversely, when we're ashamed or are being less than truthful, we tend to avoid eye contact all together.
With photography, we're trying to engage the viewer, to bring them into the photograph. There's no better way to do that than to focus on the eyes, specifically, the highlights in the eyes. A multitude of of photographic sins may be commited, but if you've captured the eyes, you've captured the viewer.
Hysteria - TeresAdora
lulu - ellemoss