I get it regularly, pretty bad and in different areas around either eye. In my case it's not about stress or caffeine, I just don't have enough tear fluid, so the eyes get dry easily. There are various kinds of eye drops oculists can recommend you for that, you also just have to try and remember to blink more often than you normally would, particularly when you're staring at screens a lot, and the eyes need rest regularly (i.e. you should sleep, pulling an all-nighter at the computer in a poorly lit room is about the worst you can do).