Background: The autonomic nervous system plays a vital role in regulating pupillary responses through sympathetic and parasympathetic pathways. Assessment of pupillary dynamics may provide a non-invasive indicator of autonomic nervous system function. Aim: To evaluate the correlation between autonomic function tests and pupillary dynamics in adults. Methods: A cross-sectional observational study was conducted among 100 adults attending the outpatient department between January and December 2025. Participants underwent standardized autonomic function tests including heart rate variability during deep breathing, Valsalva manoeuvre, and blood pressure response to standing. Pupillary dynamics were assessed using pupil diameter measurement and light reflex parameters. Statistical analysis was performed using correlation tests to determine the association between autonomic function parameters and pupillary responses. Results: Among the 100 participants, 56% were males and 44% females, with a mean age of 42.8 ± 11.6 years. Abnormal autonomic function tests were observed in 38% of participants. Participants with abnormal autonomic function showed significantly reduced pupillary constriction amplitude and delayed pupillary recovery time compared with those with normal autonomic responses (p < 0.05). A moderate correlation was observed between Valsalva ratio and pupillary constriction velocity (r = 0.42) and between heart rate variability and pupil diameter change (r = 0.38). Conclusion: Pupillary dynamics showed a significant association with autonomic function test parameters. Pupillary assessment may serve as a simple, non-invasive screening tool for detecting autonomic dysfunction in adults.

Autonomic nervous system, Pupillary dynamics, Autonomic function tests, Pupil light reflex, Autonomic dysfunction.