Working on a computer or just sitting at your desk for hours on end can be bad for your health.
Sitting to much can cause lower back problems, decrease circulation in your legs.
Typing too much can cause wrist pan and Carpal Tunnel Syndrome, staring at a computer screen all day and not taking a break can strain your eyes.
If you have to work on a computer all day make sure you take 30 minutes breaks every few hours to get up and walk away from the computer.
Take a walk outside or even just look out your window. Just focusing your eyes on something else other than your computer monitor can help your eyes tremendously.