Well, that's a really good question.
I spend almost 10 hrs a day on the screen despite I don't have to work.
Almost most of the time I would be on social media wasting my time rather than using it to productive cases.
wow thats long mate , I think you still young that's why you can carry having infront of computer that long because I can stand maximum of 5hrs
and after that My eyes will feel tired and dizzy .
maybe because of my age but this is the reason why I only using my lappy for 5 hrs then stop . but you must give importance to your eye health mate.