Look away. Frequently. I work from home, spend 10-12 hours a day looking at screens. My office is set up so I can glance out a window easily. In fact it's in my peripheral vision, that's how close it is. I look out it frequently. I'm 42, just had glasses in the last 2-3 years. The trick is to let your eye focus on something far away on a regular basis. It's like getting up and walking around, but for your eyes. It makes a huuuge difference.