Staring at a computer screen can cause eye problems. 
How to Maintain Good Eye Health:

1. Make sure your glasses or contact lens prescription is up-to-date and adequate for computer use
2. Position your computer so that your eyes are level with the top of the monitor
3. Choose a comfortable, supportive chair
4. If your eyes are dry, blink more
5. Every 20 minutes, rest your eyes by looking 20 feet away for 20 seconds

http://www.webmd.com/eye-health/good-eyesight