Dealing with an ever increasing amount of information is a major challenge in decision making. This especially pertains to information overload in managers, which is associated with impeding cognition and thus impairs objective decision making. Using visualizations to mitigate this effect has been widely discussed as a potential countermeasure. The theory of cognitive fit is far from being consistent or holistic when it comes to explaining information overload and leaves ample room for data driven advancements. In this paper we thus report the results of an experiment utilizing eye tracking that investigates how information overload alters the relationship between task complexity and decision making outcome. It is shown that information overload acts as a mediating variable between task complexity and decision making outcome and that it occurs less often when graphs instead of tables are being used. This also improves decision making outcome.