Climate change may increase the risk of various eye diseases, a study reveals.
Canadian researchers compared vision-related issues among 1.7 million people across all 50 states in the U.S. They found that individuals living in warmer areas face nearly 50% more severe vision impairment than those in cooler regions.
Exposure to stronger than normal ultraviolet (UV) light damages the cornea, lens, and retina, while also increasing the risk of irritation and infection.
Experts describe the findings as “concerning” in the context of global warming. The average global temperature has risen by 2 degrees Fahrenheit (1.1 degrees Celsius) since the late 1800s.
“The connection between vision impairment and average temperature is concerning.” (Illustrative image).
Esme Fuller-Thomson, a co-author of the study and a gerontologist at the University of Toronto, stated: “With climate change, we anticipate that global temperatures will continue to rise. It is crucial to monitor whether the rate of vision impairment in older adults increases in the future.”
Thomson, who is also the Director of the University of Toronto’s Institute for Aging and Lifelong Health, added, “The connection between vision impairment and average temperature is concerning, especially if future studies establish this link as causal.”
The study, published in the journal Ophthalmic Epidemiology, examined individuals aged 65 and older between 2012 and 2017.
Participants were asked: “Is this person blind, or does he/she have severe difficulty seeing even when wearing glasses?” Those who answered “yes” were classified as having severe vision impairment.
The report highlighted conditions such as cataracts, a clouding of the lens which is one of the leading causes of blindness in the U.S.; glaucoma, where the optic nerve is damaged; and conjunctivitis, or inflammation of the eye membrane due to irritation or infection.
Compared to individuals living in states with average temperatures below 50 degrees Fahrenheit, such as New York and Maine, those in states with temperatures above 60 degrees Fahrenheit—like Florida, Texas, and Georgia—face a higher risk.
People residing in areas with average annual temperatures of 55 degrees Fahrenheit or higher, such as Virginia, Kentucky, and California, are 24% more likely to encounter vision issues. Those in states with average temperatures from 50 to 54.99 degrees Fahrenheit have a 14% higher likelihood of experiencing difficulties.
Scientists caution that the study is observational, meaning it cannot prove that warmer temperatures lead to vision issues. They emphasize the need for further research.
However, in the report, the University of Toronto team proposes several hypotheses on how warmer temperatures may be increasing the risk of vision problems.
One hypothesis suggests that increased exposure to UV rays from sunlight is damaging the lens and other parts of the eye, raising the risk of conditions such as cataracts. They also note that higher temperatures may increase the likelihood of vision problems due to a rise in infectious diseases, such as fungal keratitis, which occurs when a fungus infects a part of the eye. Warming weather can also lead to more air pollution, which scientists warn could alter the structure of various eye components.
In conclusion, the scientists state: “If this connection is deemed causal, the projected increase in global temperatures could significantly impact the number of older adults in the U.S. affected by severe vision impairment, related health issues, and the economic burden.”
Over 24 million Americans are affected by cataracts, one of the most common eye diseases and a leading cause of blindness in the U.S.
