This prospective observational cohort study investigates whether pre-anesthetic pupillary light reflex (PLR) parameters can predict the risk of hypotension following spinal anesthesia in women undergoing elective cesarean section. Spinal anesthesia-induced hypotension is common, with reported incidence rates of 50-90%, and current predictors such as baseline blood pressure and BMI have limited accuracy. PLR, a sensitive marker of autonomic nervous system balance, may offer a simple, objective, and non-invasive tool for identifying patients at higher risk. The study evaluates pupillary reaction latency and other PLR parameters and correlates them with post-spinal blood pressure changes to determine their predictive value.