The one of the reasons the computer is so hard on your eyes is that your are spending great amounts of time staring at a object with no depth. Look out the window and your eyes are required to use depth perception and peripheral vision. Your eyes are meant to see the prey or predator on the horizon.
Good movements to counter the computer stare are as follows:
This is interesting: “How Handwriting Trains the Brain”.
Your eyes and the computer - here is a great article from the Wall Street Journal “Becoming a Squinter Nation” http://bit.ly/91tRoM