The Eyes Have it
Shakespeare is often misquoted as saying the eyes were the windows to the soul. In fact, the quote was from Guillame de Salluste, and went more like "Lovely lamps... windows of the soul."
Whoever said it, and in whatever form, eyes are extraordinary structures. Through them we read, look at art, see our mother's face blurrily after birth... Sight happens through the admission of light to the brain. So in a way, then, they are the windows to the soul.