This is one that I like to use.....it is a reprint from the visionworksusa.com website and is called Palming:
"The palming exercise will teach you to relax your eyes, which in turn will bring healthy energy to your eyes.
•First, rub your hands together until they feel warm (about 15 to 20 seconds). Then place your cupped hands over your closed eyes, being careful not to touch your eyes with the palms of your hands. The fingers of each hand should overlap and rest gently on the center of your forehead. Don't create any unnecessary pressure on your face. If your arms get tired, rest your elbows on a table.
•Sit quietly for one to two minutes with your hands over your eyes. The more relaxed you become, the blacker the darkness you will see with your eyes closed."