Myopia, or short-sightedness, is on the rise worldwide and has become a major public health issue—especially in East Asia, where large numbers of school-aged children are affected. Traditionally, factors such as family history, intensive reading, heavy screen use, and limited time spent outdoors have been seen as the main causes. Hua Yan and colleagues suggests another possible cause: poor air quality. The authors studied nearly 30,000 children in Tianjin, China, using explainable automated machine learning tools to explore the impacts of different factors on myopia, including familial myopia history, daily activity patterns, diet, and air pollution. More than half of the children had myopia. While severe myopia was largely linked to non-modifiable factors, such as genetics, mild myopia was influenced by a range of factors with around a quarter of the risk explained by modifiable factors, including air pollution. Two air pollutants—nitrogen dioxide and fine particles—stood out as important modifiable factors. These pollutants can cause oxidative stress and inflammation of the eye, potentially harming vision. The impact was strongest in primary school children.
According to the authors, cleaning the air could indirectly benefit children's vision by encouraging children to spend more time outside and giving children's eyes more opportunity to focus on distant objects. The authors add that China's recent clean air actions, which have already delivered major improvement in air quality, may bring added benefits for children's eye health in the years ahead.
