ipod touch blue screen?

I have had an ipod touch for quite some time and recentaly i was on it (like i always am) then put it to sleep for a bit. When i turned it back on the screen had turned blue. you can still see what your doing but you can see a layer of blue around all the screen.
This problem is really getting on my nerves and i have no idea what to do with it. I've tried searching around but no one seems to have the same problem as me!

Any help will really be appriecated.
Samyan (2SiK)