Vision impairment in Mexico: complementary evidence for eye-health policy—authors’ response

We thank Lozano and Razo1 for their correspondence on our article,2 which allows us to clarify its scope and distinguish descriptive findings from causal interpretation. The aetiology of vision impairment and the age and sex of those affected are essential for formulating public health interventions.1 We did not analyse them because our previous Global Burden of Disease (GBD) 2019 study characterised 12 causes of vision impairment by age and sex.3 Our recent study was complementary, providing a severity-stratified description of national and subnational trends across 32 states.