How is it, Lord, that we do not look at Thy face, when it is so near us? Teresa of Avila (1515-1582) from Enlarging the Heart

Head of Christ, from the Abbey Church of SS. Peter and Paul in Wissembourg, c.1070 (stained glass) This amazing image of Christ's face, knows as the Wissembourg Christ's Head, is one of the oldest known pieces of stained glass.

Orthodox Christians pray before icons, looking deeply into the eyes of the Savior, the Mother of God, or one of the saints.
St. Teresa of Avila wrote in Way of Perfection that she found it helpful to begin her time of prayer by holding an image of the Savior. 

I found this wonderful image in a greeting card shop when I was a girl in college. Not long ago I found that it was most likely based on the Shroud of Turin.