what causes "computer brain-death"? I don't know what else to call it, but I'm sure you've all experienced it: hours of working on the computer, you leave the computer, and realize you have the mental capacity of a broccoli. It's like your brain doesn't function normally, it's lost in a sort of haze. I've always wondered what causes it. Is it the refresh rates of the screen? the high contrast level? what is it? — it doesn't happen after hours of reading a book or working on paper, it only happens when working on the computer for long hours. Is there a known cause for it, or is it too trivial to investigate ?