Knowable Mag – By Sanket Jain
How climate change threatens eye health – Cataracts, pink eye and other ocular disorders are linked to heat, air pollution and higher UV exposure
Excerpt: For five months in 2017, farmworker Alka Kamble experienced blurred vision in one of her eyes but didn’t consult an ophthalmologist. “I couldn’t afford it, and neither did I have the time, as I had to work long hours to make ends meet,” she says.
Then Kamble saw a flyer for a free eye check-up clinic near her home in Jambhali village, in India’s Maharashtra state. The doctor there suggested immediate cataract surgery and said that overexposure to solar radiation had likely contributed to her deteriorating eyesight.
Kamble, now 55, had for decades worked long hours in the scorching heat without sunglasses or shade. Conditions have worsened as heat waves have intensified in India, she adds. “The heat has become so unbearable that farmers are finding it difficult even to work for two hours in the field during summers.” …
In recent years, researchers have found another causative factor for cataracts and other eye disorders: climate change.
Climate change is increasing risk to eye health in multiple ways. First, it is making the planet hotter — Earth’s average surface temperature in 2024 was the warmest on record. Body temperatures reaching 40 degrees Celsius (104 degrees Fahrenheit) can cause heatstroke, a condition that disrupts biological processes throughout the body. In the eyes, heatstroke damages the natural defense systems that normally counteract the buildup of harmful molecules called reactive oxygen species, explains Lucía Echevarría-Lucas, an ophthalmologist at the Hospital of La Axarquía in Spain’s Málaga province.
Another way global warming is contributing to eye disorders is by increasing our exposure to UV radiation, according to Echevarría-Lucas and and study coauthor José María Senciales González, a geographer at the University of Málaga. …
Climate change is also causing an uptick in other eye conditions. These include keratitis — an inflammation of the cornea, the eye’s clear, outermost layer — pterygium, an overgrowth of fleshy pink tissue over the white part of the eye (called the sclera) and conjunctivitis, an eye infection or irritation also called pinkeye, notes Yee Ling Wong , an ophthalmologist-in-training at Manchester Royal Eye Hospital in the UK and coauthor of a 2024 overview in the Journal of Climate Change and Health.
Rising heat, pollution, and airborne allergens — fueled by climate change — can contribute to a range of eye disorders, from infections and inflammation to cataracts.
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Side view diagram of an eye with labeled anatomy, alongside a list of eye conditions linked to climate-driven heat, pollution, and allergens
Rising heat, pollution, and airborne allergens — fueled by climate change — can contribute to a range of eye disorders, from infections and inflammation to cataracts.
One 2023 study of nearly 60,000 people in Ürümqi, in northwestern China, found that temperatures exceeding 28.7°C — just 83°F — increased the risk of conjunctivitis by roughly 16 percent compared to daily temperatures around 10.7°C, or 51°F. Longer pollen seasons and increased mold growth, both of which have been linked to climate change, are also contributing to an uptick in conjunctivitis caused by allergies, says ophthalmologist Malik Kahook at the University of Colorado School of Medicine.
Beyond these direct impacts, climate-driven droughts cause food insecurity that can lead to deficiencies in essential nutrients, such as copper and vitamins B12, B1 and B9 , that risk damaging the optic nerve. During droughts, people are often forced to use unsafe water, which also increases the risk of eye infections. …
There are ways to protect the eyes from climate-driven damage. First and foremost, outdoor workers should be given sufficient shade and frequent breaks to cool down, says Jesús Rodrigo Comino, a geographer at the University of Granada and a coauthor of the Spanish study.
