When we think about the devastating impacts of climate change, images of melting glaciers, scorching heatwaves, and rising sea levels usually spring to mind. We worry about our lungs breathing in polluted air or the safety of our homes during hurricanes. However, a new report suggests we should be just as worried about what is happening to our eyes. A team of researchers from the Indian Institute of Technology Roorkee and the University of Tennessee has published a comprehensive review detailing how the shifting climate is directly assaulting human vision. Their findings show that as the planet warms, the prevalence of blindness and ocular disease is set to rise, threatening to undo decades of progress in global health.
The researchers conducted an extensive survey of existing scientific literature, analysing data from hospital records, epidemiological studies, and environmental reports up to late 2024 and 2025. By synthesising this vast amount of data, they were able to connect the dots between specific environmental changes and corresponding spikes in eye conditions. This method allowed them to examine isolated incidents and identify a global pattern. They found that the eye, our window to the world, is uniquely vulnerable because it is a mucosal surface directly exposed to the elements. Unlike internal organs protected by layers of tissue, our eyes are on the front lines of environmental defence.
Did You Know? The World Health Organization estimates that at least 2.2 billion people globally have a vision impairment, and at least half of these cases could have been prevented with appropriate care, a gap that climate change threatens to widen. |
The eye possesses a delicate balance of immune defences, including tears that flush out particles and specialised cells that fight off infections. However, the study explains that environmental stressors are overwhelming these defences. For instance, high levels of particulate matter (PM2.5 and PM10) from pollution and wildfires can suppress the antimicrobial peptides in our tears. This leaves the eye open to infection and inflammation. Furthermore, the sheer physical stress of heat and ultraviolet (UV) radiation causes oxidative stress, a chemical imbalance that damages cells in the cornea and retina. When the ozone layer depletes, more UV radiation reaches the Earth’s surface. The report notes that UV levels can escalate significantly with rising temperatures, accelerating conditions like cataracts and cancers of the eye surface.
One of the most significant findings of the report is the connection between air pollution and glaucoma, a leading cause of irreversible blindness. The researchers highlight a recent large-scale study from the UK Biobank that found that people living in areas with higher levels of particulate matter pollution were more likely to develop this condition. The tiny pollution particles can enter the bloodstream and cause inflammation that affects the optic nerve. Similarly, the changing climate is altering the behaviour of infectious diseases. Warmer, wetter weather is expanding the breeding grounds for vectors like mosquitoes and flies. This has led to a resurgence or spread of diseases like trachoma and onchocerciasis (river blindness) in areas where they were previously under control.
The report also details how extreme weather events act as immediate threats to vision. During heatwaves and droughts, the incidence of dry eye disease skyrockets because low humidity causes tears to evaporate too quickly. Conversely, floods and hurricanes often lead to outbreaks of conjunctivitis (pink eye) due to contaminated water and debris. The authors point out that even the smoke from increasingly frequent wildfires is a major culprit, with data suggesting that up to 70 per cent of people exposed to wildfire smoke report ocular issues ranging from irritation to severe inflammation.
The authors also acknowledge limitations in the current state of knowledge. They note that while the link between climate and eye health is becoming clearer, there is a lack of detailed data on how these changes affect different socioeconomic groups. They also highlight that the healthcare industry itself is part of the problem. The review mentions that cataract surgery, one of the most common procedures globally, has a significant carbon footprint. In the UK, a single surgery generates over 180 kg of carbon dioxide, whereas efficient systems in India have reduced this to just 6 kg.
The authors emphasise that the burden of climate-induced eye disease will not be shared equally. Low-income populations, the elderly, and those in developing nations with limited access to healthcare will suffer the most. Malnutrition caused by climate-related crop failures can lead to Vitamin A deficiency, a known cause of blindness in children. Therefore, this work serves as a clarion call for policymakers. It suggests that protecting public health in a warming world requires more than just building sea walls; it requires strengthening healthcare systems, reducing emissions, and ensuring that we do not lose sight of our future.
This article was written with the help of AI and edited by an editor at Research Matters.
