Delirium is commonly observed in critically ill patients in intensive care units (ICUs), imposing significant burdens on both patients and the healthcare system. Existing assessment tools have certain limitations. Studies have indicated a correlation between pupil parameters and neurological disorders including delirium. Automated Infrared Pupillometry, widely used in neurological disorders, is employed in this study to assess its accuracy and predictive power in evaluating delirium among critically ill patients. The aim is to investigate the accuracy and predictive capability of these parameters in assessing delirium, while identifying the optimal cut-off points. The research findings will contribute to enhancing early detection and prevention of delirium in ICU settings.