Operator competence is critical to ensure safe and profitable operation in hazard intensive chemical process industries. Human errors account for the majority of the accidents in these industries. Therefore, it is imperative to develop methodologies to assess the competence of operators to minimize human errors. Traditional approaches to elicit operator competence are based on subjective measures and/or measures derived primarily from the process and operator actions. These approaches ignore the cognitive aspects of operators such as perception, decision-making strategy, and workload, which are crucial for improving performance. Recent development in sensor technology has enabled the researchers to measure human cognitive behavior objectively. Sensors such as eye-Tracking, electroencephalography (EEG) and galvanic skin resistance (GSR) are found to provide intrinsic human characteristics that cannot be measured otherwise. In this paper, we discuss how eye-Tracking can be used to capture control room operators' cognition and help infer their competence. Eye-Tracking provides information about the location of a person's gaze, which serves as a trace of their attention allocation. Eye gaze based metrics show a strong correlation with operator cognitive behavior such as situation awareness and cognitive workload during process monitoring tasks. © 2021 IEEE.