Eye blinking: Blink eyes 20 times at a go by cupping them loosely with hands. Repeat it three times.
Eyeball rolling: Take a deep breath and gently close your eyes. Roll the eyeballs both clockwise and anticlockwise ten times each while holding the breath. Gradually open eyes while slowly breathing out. Do it 5 times.
Eye palming: Sit straight and rub palms against each other till they become slightly warm. Then, lightly cup eyes with your palms for 15-20 seconds. Do it three times.
If you do a lot of reading or spend time on the Internet, these exercises should be done after every two hours.