Or a lack of light when you trade in the night time in the dark and have only light from your pc. I tend to not turn on lights when my pc is on. I guess I can suffer from such darkness. We can suffer from pear syndrome as well from not getting physical exercise or moving around due to trading. I mean if you solely depend on it for income, you will be so miserable if you walk out with no profit and all loss someday and I know so for newbie or some traders but as you gain experienced, it will be more pleasant for you and more of an earning experience. I mean the losing part will hurt anyone.Yes, getting addicted to Forex could be a very bad part of it because of it's attendant side effect ranging from psychological to health. There are a few people I know that are always on their system trading and they hardly take some break off. In a long run, it begins to affect their eyes due to the retina's long exposure to direct light from the screen.