What the blogger is writing about is real and a issue. But that deals more with moderation of usage.
Whatever is causing the immediate symptoms (dithering, PWM) happens literally within seconds or minutes like KM said.
Because of that, things like "working in a well light area", "non-glare screens", etc won't help.
It's two separate problems
I'm sure if your head pressure problem is like what I had, you will feel healed within two weeks. If it didn't happen, do not hesitate to have a serious checkups and look for professional help.
Took me over 7 months to feel all the way better. If I'm exposed to a monitor with PWM for more then 30 seconds though, I immediately notice it.
The overuse one I also now notice (with the previous one gone) and I actually feel better within a hour, much better within a day.