JTL Overuse. That's the thing that's interesting. All of us here seem to be IT professionals. Maybe that's why when we complain to people about our eyes, they give us a long blank stare wishing to blurt out "ya think!?"
Although some of us have different symptoms, some of which cannot be explained due to simple eyestrain. For example, I get a very sharp and pronounced headache for hours or even days after just a few minutes of looking at an LED-backlit flatpanel display (even with fresh rested eyes). My "solution" is to avoid LED displays like the plague. That cannot be chalked up to your garden-variety "eye strain".