Lightheaded/dizzy and eyes hurt?

Eyes hurt when using computer... but I have very good vision...?

• I went for an eye test and I apparently have better than 20:20 vision, but my eyes really hurt when I use the computer. Sometimes if I've been on a computer for an hour, if I turn the light on (for instance if it's gone dark - I always use the computer in good light) and I can't stand it, my eyes hurt so much. Sometimes I even have to go sit in the dark to let my eyes rest, they hurt so much! I have to go on the computer daily because of work, for at least 3 hours, but I do try to have breaks, but still my eyes hurt. I did briefly (for like 1 minute) try on my friends glasses who has them for the computer, and the pain almost immediately went away - because of my good vision I don't need glasses, but I think I do... can anyone help!?

• Answer:

  Something is wrong with your computer i think, if you didn't already switched to flat screen do it, also try adjusting luminosity and stuff. Also the way you sit and the height of the screen can do this.