Keep Healthy While Work Infront of computer all the day?

That is pretty hard.I am also work in front of computer.I find my eyes and left-arm are un-healthy this year.Too long time stay front the PC,that is really harmful. Now, I stand up and do some relax activity every 20 minutes,looking far,turning around the neck and head,moving arms and waist,that is helpful to keep our body healthy.

I am particularly worried about my eyes as I have gone through a lasik laser to improve my eye sight but I again feel some eye sight problem.I work on computer fot about 9 hrs daily.For me there is no way to keep my healthy except taking some rest after a certain interval,washing my eyes & putting a good eyedrop.