I am glued at my desks while typing away the computer for an average of 8 hours a day is part of my normal routine.
Almost more than 12 to 14 hours a day, my computer is switched on and I use it for atleast 12 hours, more not less.
I find when I am on less I can be more productive with that time, it is easy to procastinate for me when I have all day to do articles and there's 20 more fun things to do you know? I would say I limit myself to about 8 hour a day.
I'm currently using it 10 hours a day, for work. However I need to start cutting back a bit more on it, and start going outside Mojachie.