But in all seriousness the problem with large monitors and eyestrain comes from the fact that we are better at reading narrow columns of text, and since people tend to maximise their windows they get eyestrain due to really wide columns on a wide monitor.
With CRT's there was the fear of the fact that a cathode ray tube was actually hurling radiation at the glass, and some of it was going to affect your eyes.
With LCD's the problem is not really relevant any longer any more, you should be more worried about radiation being emitted from your gigahertz processor.
So in conclusion follow the OH and S procedures available online in regards to lighting your workspace, stick to narrow columns on your webpages and you should be fine.
May I ask what you need dual 30"'s for? I had a 30" at work and it was fine for c# .net programming, I could even work on two solutions side-by-side or have outlook, a web browser and my IDE Open. At home I have a 24" and I find it sufficient to my needs most of the time, but I also have an old 17" lcd attached to my PC that I use to read email. I couldn't imagine needing 2 30"'s