Yuan N, Li J, Tang S, et al. - Researchers examined 1,400 Hong Kong children in this cross-sectional investigation to evaluate the link between choroidal thickness and secondhand smoking exposure in children. From January 2016 to July 2017, the consecutive recruitment of children aged 6 to 8 years from the population-based Hong Kong Children Eye Study at the Chinese University of Hong Kong Eye Centre was done. Detailed ophthalmic examinations were conducted among all participants. There were 1,400 children in total, with 941 (67.2%) having no exposure to secondhand smoking and 459 (32.8%) with exposure to secondhand smoking. Findings revealed a link between exposure to secondhand smoking and choroidal thinning, along with a dose-dependent effect, in this pediatric population. The evidence about the potential hazards of secondhand smoking to children was supported by these findings.