I also read somewhere that staring at a computer screen for a long period of time weakens the eyes. It suggested that every 20 minutes you should get out of you

I also read somewhere that staring at a computer screen for a long period of time weakens the eyes. It suggested that every 20 minutes you should get out of your seat and walk around, concentrating on objects different distances away. I don't have any scientific proof of this but I try to do it when possible as well. Once or twice per day I try to go outside and focus on things as far away as possible and try to make out detail. It definitely makes me more relaxed when I sit back down to work again.