When you land in a polluted city, the difference in air quality can hit you immediately. The air feels heavier, your throat feels dry, and within a few minutes, your eyes may begin to sting. These are some of the short-term effects of air pollution (i.e., effects that result a few hours or days following exposure). In addition, long-term exposure to air pollution (exposure to air pollution for months or years), can have a variety of health effects ranging from impacts on neonatal and children’s health like premature birth, stunting, to cardiovascular and respiratory effects like lung cancer, dementia, diabetes and stroke (factsheet on health effects). One potential impact that often gets overlooked is the impact on eyes, including the development of cataracts.
A cataract is the clouding of the lens in the eyes that may cause blurred vision or blindness. 1 Cataracts are the leading cause of blindness worldwide. 2 The impact of cataracts on vision loss, particularly in older adults, can significantly alter an individual’s quality of life. The major risk factors for cataracts includes age, gender, metabolism, environmental factors and coverage of cataract surgery. 3 Over 90% of people with cataracts live in low- and middle-income countries (LMICs).3 This is largely due to poor awareness, limited eye care facilities, and high cost of cataract surgery. 4 Large regional disparities exist in access to cataract surgery; surgery rates range from about 10,000 per million population in high-income countries to fewer than 500 per million in the poorest parts of East, West, Central and Southern Africa. 5
A decade of rising disability burdens
The Global Burden of Disease (GBD) study quantifies how diseases and injuries affect people all around the world. Cataract does not usually cause death; however, it can affect vision and impact the quality of life. Hence, GBD measures the cataract burden in terms of disability and not mortality. The cataract health burden is measured in Disability-Adjusted Life Years (DALYs), which combines the years of healthy life lost due to vision impairment and the years lived with disability.
Globally, in 2023, there were 105 million cases of cataracts and 7 million DALYs were associated with cataracts. Thirty percent of these healthy years of life lost due to cataracts (2 million DALYs) were attributable to air pollution exposure, an increase of 16% since 2013.
Evidence linking air pollution to cataracts
Around 41% of populations in LMICs use solid fuels for cooking inside the household. Strong evidence has been established between exposure to household air pollution (HAP) and cataract formation. The following evidence highlights the key links between household pollution and the development of cataracts.
- WHO Study on global AGEing and adult health (SAGE) found that unclean fuels (e.g., biomass) are associated with self-reported cataract in India and China. Higher risk was found in women, people older than 60 years old, and those who live in rural areas. 6
- A hospital-based case-control study conducted along the Nepal–India border showed that the use of solid fuel in unfuelled indoor stoves was associated with an increased risk of cataract among women who do the cooking. 7
- Another study conducted in North and South India provided robust evidence of an association between biomass fuel use and cataracts among women. 8
- Among Chinese adults, long-term solid fuel use for cooking was associated with higher risks of developing cataracts. Switching to clean fuels appeared to mitigate the risks. 9
There is relatively limited evidence of an association between exposure to ambient air pollution and cataract.10
- In France, long-term exposure to a NO₂ concentration ≥ 40 μg/m3 was associated with an increased incidence of cataract surgery. 11
- Among Korean adults aged ≥50 years, exposure to PM₁₀, NO₂, SO₂, and O₃ was associated with cataract development.12
In rural areas of West Bengal, India, a direct link was observed between outdoor air pollution and the development of cataracts. Increase in oxidative stress due to air pollution was found to impact eye health.13
An enormous disparity in disease burden across regions
The highest number of healthy years of life lost due to cataracts from air pollution in 2023 were in South Asia (1 million DALYS), Southeast Asia, East Asia and Oceania (751,000 DALYS), and East, West, Central and Southern Africa (243,000 DALYS) (Figure i).
When examined by Socio-Demographic Index (SDI), a composite index based on income per person, education level, and fertility rate, the burden varies significantly.
- Low (636,000 DALYs) and low-middle (603,000 DALYS) SDI countries face the highest burdens of cataracts due to air pollution exposure.
- The rate of healthy years of life lost in low SDI countries (76 people per 100,000) is nearly 4 times higher than the rate in high-middle SDI countries (20 people per 100,000), who faces the lowest associated burden.
Similarly, countries in low and low-middle SDI regions typically also face higher exposures and burdens related to household air pollution specifically, which is a significant risk factor to onset of cataracts.
Figure i: Number of DALYs associated with cataracts attributed to household air pollution in 2023.
The burden of cataract due to air pollution is disproportionately higher among women and low-income populations. Although cataracts are largely treatable with timely medical intervention, limited access to eye care, financial constraints, and inadequate health systems mean that many individuals continue to live with avoidable visual impairments. This adds an additional layer of vulnerability that is rooted not only in biological risk such as ageing and disease, but also in social and economic inequities. In addition to rising air pollution, rising temperatures may also contribute to the development of cataracts and the impact is higher among older adults. 14
Progress is within reach
Progress has been made in some parts of the world. Over the past decade, the burden of air pollution–related cataracts have declined in high, high-middle, middle, and low-middle SDI countries. In contrast, low SDI countries have experienced a sharp increase in this burden. Addressing air quality could play an important role in preventing cataracts and improving overall eye health, while also reducing the financial burden of medical care. Ongoing efforts to promote access to cleaner cooking fuels and strategies aimed at reducing urban pollution are important first steps. Targeted policies and greater investments on clean energy and continued subsidies for cleaner fuel especially in LMICs are highly crucial to protect the most vulnerable. National health policies can include air pollution as one of the risk factors for cataracts and provide strategies to raise awareness about the link between air pollution and cataract development.
References
1. World Health Organization, Eastern Mediterranean Regional Office. 2026. Cataract [Internet]. 2026. Available from: https://www.emro.who.int/health-topics/cataract/
2. Jiang X, Xu B, Zhai J, Huang S, Cheng H, Ma L, et al. 2025. Global trends in cataract burden: a 30-year epidemiological analysis and prediction of 2050 from the Global Burden of Disease 2021 study. Br J Ophthalmol. https://doi.org/10.1136/bjo-2025-327776
3. Lin L, Liang Y, Jiang G, Gan Q, Yang T, Liao P, et al. 2025. Global, regional, and national burden of cataract: A comprehensive analysis and projections from 1990 to 2021. Obasuyi OC, editor. PLoS One. 20(6). https://doi.org/10.1371/journal.pone.0326263
4. Jolley E, Virendrakumar B, Pente V, Baldwin M, Mailu E, Schmidt E. 2022. Evidence on cataract in low- and middle-income countries: an updated review of reviews using the evidence gap maps approach. International Health. 14. https://doi.org/10.1093/inthealth/ihab072
5. Wang W, Yan W, Fotis K, Prasad NM, Lansingh VC, Taylor HR, et al. 2017. Cataract Surgical Rate and Socioeconomics: A Global Study. Invest Ophthalmol Vis Sci. 57(14). https://doi.org/10.1167/iovs.16-19894
6. Li X, Guo Y, Liu T, Xiao J, Zeng W, Hu J, et al. 2021. The association of cooking fuels with cataract among adults aged 50 years and older in low- and middle-income countries: Results from the WHO Study on global AGEing and adult health (SAGE). Science of The Total Environment. 790. https://doi.org/10.1016/j.scitotenv.2021.148093
7. Pokhrel AK, Smith KR, Khalakdina A, Deuja A, Bates MN. 2005. Case–control study of indoor cooking smoke exposure and cataract in Nepal and India. International Journal of Epidemiology. 34(3). https://doi.org/10.1093/ije/dyi015
8. Ravilla TD, Gupta S, Ravindran RD, Vashist P, Krishnan T, Maraini G, et al. 2016. Use of Cooking Fuels and Cataract in a Population-Based Study: The India Eye Disease Study. Environ Health Perspect. 124(12). https://doi.org/10.1289/EHP193
9. Chan KH, Yan M, Bennett DA, Guo Y, Chen Y, Yang L, et al. 2021. Long-term solid fuel use and risks of major eye diseases in China: A population-based cohort study of 486,532 adults. Bates MN, editor. PLoS Med. 18(7). https://doi.org/10.1371/journal.pmed.1003716
10. The Scottish Government. 2023. Review and Assessment of the Evidence on Health Impacts of Low-Level Pollution in Countries with Levels of Ambient Air Pollution Comparable to Scotland. October 2023. 2023.
11. Gayraud L, Mortamais M, Schweitzer C, De Hoogh K, Cougnard‐Grégoire A, Korobelnik J, et al. 2025. Ambient air pollution exposure and incidence of cataract surgery: The prospective 3City‐Alienor study. Acta Ophthalmologica.103(3). https://doi.org/10.1111/aos.16790
12. Shin J, Lee H, Kim H. 2020. Association between Exposure to Ambient Air Pollution and Age-Related Cataract: A Nationwide Population-Based Retrospective Cohort Study. Int J Environ Res Public Health. 17(24). https://doi.org/10.3390/ijerph17249231
13. Ghosh S, Choudhury SP, Mukherjee G, Dey A. 2022. Effect of Air Pollution and Oxidative Stress in Development of Cataract- A Study in Rural Regions of West Bengal. EEC. https://doi.org/10.53550/EEC.2022.v28i02s.055
14. Lv X, Gao X, Hu K, Yao Y, Zeng Y, Chen H. 2022. Associations of Humidity and Temperature With Cataracts Among Older Adults in China. Available from: https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2022.872030/full
