An important element of human factors engineering (HFE) pertains to measurement and evaluation (M&E). The role of HFE-M&E should be integrated throughout the entire control room modernization (CRM) process and be used for human–system performance evaluation and diagnostic purposes to resolve potential human engineering deficiencies and other human–machine interface design issues. NUREG-0711 describes how HFE in CRM should employ a hierarchical set of measures, particularly during integrated system validation, including plant performance, personnel task performance, situation awareness, cognitive workload, and anthropometric/physiological factors. Historically, subjective measures have been primarily used since they are easier to collect and do not require specialized equipment. However, there are pitfalls with relying solely on subjective measures in M&E such as negatively impacting reliability, sensitivity, and objectivity. As part of comprehensively capturing a diverse set of measures that strengthen findings and inferences made about the benefits from emerging technologies like advanced displays, this paper discusses the value of using eye tracking as an objective method that can be used in M&E. A brief description of eye tracking technology and relevant eye tracking measures is provided. Additionally, technical considerations and the unique challenges with using eye tracking in full-scale simulations are addressed. Finally, this paper shares preliminary findings regarding the use of a wearable eye tracking system in a full–scale simulator study. These findings should help guide future full–scale simulator studies using eye tracking as a methodology to evaluate human-system performance.