Does staring at a computer screen ruin your eyes?

i spend almost the whole day staring at a computer screen. i've never had any problems with eyes. my eyes sometimes feel tired but just after reading or after many hours of studying... i'm the lucky one but i think it won't last forever)

u may need glasses ????

LED monitors are somewhat better than CRT. CRT displays were often not as sharp, and even if they did go slightly out of focus (straining your eyes), it wasn't always noticeable that they had done so. LCD's can still strain your eyes though. Its not good to be focusing at such a close distance for long periods of time, which is why most health advice suggests taking a 5 or 10 minute break per hour, and also looking above your monitor into the distance regularly (this isn't always posible though, especially if you're facing a wall). The other problem with all monitors, is that unless you have a macbook or a fairly modern laptop, the brightness of the screen does not adjust according to ambient daylight. There is a great (and free) app which can help with this, called Flux. http://stereopsis.com/flux/ Give it a try, its for Windows and Mac, and adjusts your screen brightness and 'temperature (ambient color)' according to the time of day. Ive been using it for around 2 years and It didnt take long for me to realise it was really helping my eyes from being so tired (I stare at an lcd for around 12 hours a day)