Hi Saxo_boi, I too suffered headaches at work and had the all clear from my optitions as far as my vision was concerned however what he did say was that I should change my desk about. Is your computer screen showing reflection from a window behind you? This can put a strain on your eyes so you should try a filter for your screen or moving your desk about. With your eyes becoming sore, you may have something called Dry Eye. This makes your eyes feel gritty and sore, I get this too but take eye drops to help lubricate them. Also, when you are concentrating on something on the computer, you blink less therefore your eyes become dryer and more irritated,
Hope this helps :o)