This experiment investigated the implementation of eye tracking within the control room environment. Three overview displays (Surface Chart, Heat Map, and Visual Thesaurus) were used to both establish which results in better performance and how eye movement behavior can be used to infer cognitive processing components. 48 operators participated in a human-in-the-loop test bed simulating a crude oil process monitoring task. The experiment was a 3 (display type) × 2 (complexity level) × 2 (trial) mixed factorial design. The eye movement behavioral metrics provided interpretations which are largely consistent with performance metrics for the complexity and trial factors. The display factor indicated that the eye metrics were not consistent with performance metrics. While the Surface Chart display facilitated better performance, eye metrics indicated that the Visual Thesaurus display had the preferred monitoring behavior. While comparing eye metrics between visualizations is not recommended, the results of this research indicate that eye tracking metrics could be used within a constant process control stimulus environment (consistent visualization) in order to make interpretations of changes in: operator monitoring efficiency and behavior (such as top-down vs. bottom-up processing, and local vs. global attention), operator workload, and attention allocation areas through gaze points and ROIs.