Quantitative effects of sleep deprivation on digital pupillary dynamics and visual evoked potential metrics in healthy adults

OBJECTIVES: The pupillary light reflex (PLR), pupillary sleepiness test (PST), and visual evoked potentials (VEPs) are crucial for assessing the functional integrity of the visual and autonomic nervous systems. These responses integrate retinal phototransduction with midbrain reflex pathways and cortical visual processing, all of which are influenced by physiological and clinical disorders. Their temporal dynamics lay the groundwork for using pupillary reflexes and cortical potentials as biomarkers of fatigue and the effects of psychoactive substances on them. This study aimed to identify physiological biomarkers of fatigue by evaluating the PLR and VEPs. MATERIAL AND METHODS: These modalities were validated against the PST, pupillary unrest index parameters, and blink-rate analysis to assess autonomic and cortical contributions to fatigue. This study examined the effects of 48-hour sleep deprivation on pupillary behavior in 18 healthy adults under controlled conditions. These complemented the established fatigue indices, including constriction velocity, relative amplitude, time of minimum diameter, and latency. Visual evoked potentials analysis demonstrated that sustained wakefulness modulated cortical responses, with a delay and amplitude reduction in the N145 component. CONCLUSIONS: assessments. Int J Occup Med Environ Health. 2026;39(5).