It's one of the occupational hazards of computer use: eye strain, fatigue, and repetitive strain injury (RSI). Computer Vision Syndrome (CVS) is a definite risk.
It's important to take a break from time to time - but how do we do that when there's so much work to be done? So many web sites to visit? Another forum post to read?
In order to help safeguard your vision, experts recommend following the 20-20-20 rule. For every twenty minutes of computer work, look away at something twenty feet away for twenty seconds.
Setting a timer of some kind to remind yourself to take a break can be helpful. Here's what I do: I use a reminder application to keep track of my activity, and let it tell me when to take a break.
Pay attention to ergonomics. Posture, workstation layout, and the position of the keyboard and monitor can have a tremendous impact on your health and comfort.
Take a break!
RSI and Eye Strain
I'm a software developer, so I thought RSI is not a big problem for me. After all I don't type all day long. Eye strain, yes. But not RSI.
Then I've installed WorkPause (reminder app) which also counts the number of mouse clicks and key presses you make during the day.
My numbers are: more than 14000 key presses and more than 6000 mouse clicks for a typical 8-hour working day. And that without the computer usage at home. That's not a small number; definitely pay attention to ergonomics.