John Armstrong has a good post on icons. I liked this part a lot:
Frederica Mathewes-Green , in her helpful new book The Open Door: Entering the Sanctuary of Icons and Prayer (Paraclete Press) urges readers to look at the Pantocrator icon from St. Catherine’s Monastery in Sinai, Egypt. This is the oldest known icon of Christ. She urges readers to use paper to cover the picture so you can only see one eye at a time. Then switch the paper and look at the other eye while you cover the one you first looked at. You will readily see that the right eye presents a penetrating stare, a stare Mathewes-Green says will make you wonder if this person knows more about you than you care for them to know. Now when you cover the right eye and look at the left eye of the icon you will see something different. On this side Christ’s face is peaceful and serene. Christ beckons you to come to him, to embrace him and love him. I actually did what Mathewes-Green suggested and she is right. The great truth of Christ’s person pours through this amazing window into your soul.
The writer of this famous icon was clearly trying to show two great truths. First, he wanted to show that Christ knows our sinfulness and everything there is to know about us. This is what Mathewes-Green calls a “surgical aspect.” But the iconographer clearly wants us to also observe the patient, listening side of Christ as well.
You can try it yourself. Here’s the full version of the icon,
And here’s a close-up of the face with grid lines added, from a site comparing it with the Shroud of Turin: