Climate Change and Its Impact on Ocular Health: A Systematic Review.

Climate change has emerged as a pressing public health concern, with growing evidence that its environmental impacts extend to ocular health. Rising ultraviolet (UV) radiation, deteriorating air quality, and extreme weather events contribute to both acute and chronic eye diseases. This systematic review examines existing literature linking climate-related environmental exposures to ocular disorders, focusing on cataract formation, dry eye disease (DED), and meteorologically induced ocular surface instability. It also identifies at-risk populations and research gaps to inform clinical and policy responses. A comprehensive search of peer-reviewed articles published between 2000 and 2024 was conducted using PubMed, Scopus, and Web of Science. Inclusion criteria encompassed original research, epidemiological studies, and reviews that examined the effects of climate change, UV radiation, air pollution, or meteorological variation on human ocular health. Exclusion criteria included studies focused exclusively on indoor risk factors or lacking environmental context. A total of 18 studies met the inclusion criteria and were thematically synthesized across three core domains: (1) UV exposure and cataracts, (2) air pollution and ocular surface disorders, and (3) meteorological variability and ocular physiology. Evidence indicates strong associations between increased UV-B exposure and elevated cataract risk, particularly in equatorial and high-sunlight regions. Air pollutants - especially PM2.5, ozone, and nitrogen dioxide - were linked to higher prevalence and severity of DED due to tear film instability and surface inflammation. Climatic shifts such as heatwaves and humidity drop further exacerbate ocular surface stress. Vulnerable groups include outdoor workers, elderly individuals, and populations in low-resource or high-pollution regions. Environmental changes driven by climate disruption pose an increasingly recognized threat to ocular health. Addressing this challenge requires multidisciplinary research, public health preparedness, and equitable access to eye care and protective resources.