Robin Hanson, an economist who blogs at Overcoming Bias, posts on What the Eyes Say. He points out something I have known for a while, but hardly have at the forefront of thought, which is that humans have "the largest and most visible sclera – the “whites” of the eyes – of any species," which allows us to communicate quite a bit with our eyes. Ah yes, the eyes, which are the windows to our souls. We can communicate direction with a glance. We can give ourselves away with a glance.
How much literature deals with eyes, glances, etc.? A great deal. Volumes worth of literary analysis, I'm sure. Who is ready to write "A Sclerical Analysis of Literature"?