Background: Evidence concerning greenspace and ocular and adnexal diseases (OADs) is scarce. Methods: This prospective cohort study followed 241,576 UK participants from baseline (2006-2010, age range: 37 to 73 years old) until May to October 2022, identifying 9 OAD subtypes through electronic health records. Residential greenspace was evaluated using the percentage of greenspace (GS%) derived from the 2005 General Land Use Database. Cox proportional hazards models and mediation analyses were employed to assess the associations. Results: The associations between greenspace and OAD varied by subtype, exhibiting nearly inverse J-shaped or inverse U-shaped exposure-response curves. Comparing the highest with the lowest quartile of GS% within a 300-m buffer, beneficial associations were observed for (a) lens disorders [hazard ratio (HR): 0.931 [95% confidence interval (CI): 0.896 to 0.968]] and (b) choroid and retina disorders (HR: 0.935 [95% CI: 0.874 to 1.000]). These beneficial associations for lens disorders were partially mediated by physical activity and air pollution. In contrast, detrimental associations were found for (a) eyelid, lacrimal system, and orbit disorders (HR: 1.082 [95% CI: 1.018 to 1.150]) and (b) conjunctiva disorders (first quartile versus third quartile, HR: 1.129 [95% CI: 1.027 to 1.241]). Conclusions: Greenspace exposure may exert both beneficial and detrimental associations across various OAD subtypes. The findings may inform the development of area- or individual-level greenspace interventions to mitigate OAD burden.
