Shift your eyes away from the screen for 20 seconds every 20 minutes. Also, you should not be on the computer or sitting down for two hours straight, as this is fatal to health. Please get up and walk around for a minute or so no less than once an hour tops.

Thanks for the tip!

Download f.lux

It's basically a software that changes the contrast and brightness of your screen to adjust for tired eyes.

You could also get gunnars (special glasses designed for looking at a computer screen for a long time)

also there is a chrome addon called St ylish you should consider downloading, it can give most sites you visit a dark grey theme instead of pure white like alot of these websites do, it really has helped me. anyway yeah google Stylish chrome addon