OBJECTIVES: We aimed to evaluate the effects of cataract surgery on cardiac autonomic modulation. METHODS: A cross-sectional and analytical study was conducted at the Hospital Maria Braido in the city of Sa˜o Caetano do Sul, Sa˜o Paulo, between 2015 and 2016. We investigated 19 patients of both sexes who were all over 50 years old; all patients had a diagnosis of senile or bilateral cataracts and were recommend...