Wildfire smoke in your eyes? Doctors say we need to study long-term impacts
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Kate LeBlanc remembers how wildfire smoke that drifted across the skies of New Brunswick earlier this summer clung to her eyes, making them feel gritty.
"It's like having a pair of glasses on that you can't clean," said the 71-year-old resident of Bathurst, N.B. "It really felt like fine grains of sand or something."
The smoke, on top of her seasonal allergies, meant LeBlanc was constantly flushing out her eyes. She told CBC News that she used a bottle of eye wash drops and two bottles of allergy drops in just a few months.
"I basically hide out," she said of how she prevents symptoms. "I don't go outside, I don't open the windows."
This year, wildfires in Canada have been the worst on record, with winds pushing smoke across the country and into parts of the United States. On these especially hazy days, some eye doctors told CBC News they saw more patients reporting irritated eyes.
Eye health experts are concerned that as wildfires become a more common phenomenon, we aren't studying the long-term impacts the smoke could have on our eyes.
What are the immediate symptoms?
"There's particulate matter, volatile organic compounds," said Dr. Marisa Sit, a Toronto ophthalmologist with the University Health Network's Comprehensive Ophthalmology Unit at the Donald K. Johnson Eye Institute.
"These are things [in the smoke] that can irritate our eyes.
Dr. Marisa Sit is an ophthalmologist at the University Health Network's Comprehensive Ophthalmology Unit in the Donald K. Johnson Eye Institute in Toronto. (Jennifer La Grassa/CBC)
Wildfire smoke in the eyes can cause them to feel dry, itchy, red, painful, watery and gritty — all symptoms similar to seasonal allergies. This sort of inflammation of the conjunctiva, or white part of the eye, is known as conjunctivitis.
If the cornea — or clear part of the eye — becomes inflamed, it's called keratitis.
At times, this inflammation can even cause vision to blur.
According to Vancouver ophthalmologist Dr. Briar Sexton, these eye symptoms can happen before we smell or see the smoke.
Even though this type of temporary irritation can be soothed with a lubricant like over-the-counter artificial tears, doctors worry about the impact of chronic long-term exposure to harmful smoke particles.
"When I first moved to B.C. and started practising in 2006, we weren't talking about wildfires anywhere near the way that we are now," said Sexton.
"The amount of exposure any single individual would get was actually quite minimal compared to [what] they are getting in hot spots these days."
Long-term impacts unclear
Sexton said it's not clear what lasting damage wildfire smoke can do to the eyes. "I wish I knew the answer."
The doctors who spoke with CBC News draw conclusions from studies done with pollutants that have similar components as wildfire smoke.
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For example, cigarette smoke has been found to be a risk factor for macular degeneration — an eye disease that can eventually lead to legal blindness.
Toxic substances from cigarettes have also been linked to an increased risk of cataracts.
Sukanya Jaiswal, an optometrist in Australia, examines a man's eyes. Jaiswal began researching the impact wildfire smoke can have on long-term eye health after the intense 2019-2020 bushfire season in Australia. (University of New South Wales)
"If I had a magic crystal ball, I do think those are things we're unfortunately going to see being linked to wildfire regions in higher incidences in the future," Sexton said.
Australian researchers dig deeper
A review last year found that more than 70 per cent of people experienced eye irritation during a period of poor air quality during Australia's intense wildfire season in 2020. And people with pre-existing eye or respiratory conditions seemed to have more symptoms.
The review also acknowledged that there's very little research on the subject. These gaps pushed the review's author, Sukanya Jaiswal, an optometrist in Sydney, to look a little deeper.
About four years ago, the bush fire season in Australia was so severe and devastating that it was referred to as the Black Summer.
During that time, patients came to Jaiswal in need of remedies to soothe red and swollen eyes, but she says she wasn't always sure what to prescribe.
"I think it's really serious," she told CBC News.
"Millions of people are being exposed to smoke throughout the year, and in a way that we have not seen before and in a way that we are not prepared for."
To fill in some of the research gaps, Jaiswal is conducting studies at the School of Optometry and Vision Science at the University of New South Wales.
In particular, she's been looking at the short and long term impacts wildfire smoke can have on each individual part of the eye and how long recovery takes — especially among groups like firefighters that are frequently exposed.
In some of these studies, Jaiswal uses a pair of goggles that release small amounts of smoke. Using this research, Jaiswal wants to identify who is most at risk and whether any of the damage incurred is reversible.
"If we don't have a uniform understanding of how we should protect the eyes and how we should manage any eye disease that does occur from wildfire exposure, I think our patients are going to suffer," she said.
Tips to protect your eyes
Health Canada told CBC via email that it doesn't have expertise specific to eye health, but doctors like Sit say that it's important for the country to invest in research to identify how wildfire smoke can effect our eyes.
Sexton says she worries that by the time we have a better understanding of how our eyes are impacted by wildfire smoke, "it's going to be too late" for people who didn't take precautions.
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Sexton says she knows some people are using allergy eye drops to alleviate symptoms, but she warns that medicating eyes unnecessarily could have unintended consequences. Instead, she says it's better to rinse the eyes with artificial tears.
Here are some other precautions ophthalmologists say you can take to protect your eyes from smoky conditions:
Stay indoors where there is filtered air.
If you must go outside, wear protective eye gear that seals around your eyes.
Rinse your eyes with artificial tears.
Don't look directly at the sun.
Clean your eyelashes and eyebrows to remove any small particles.
Don't rub your eyes.
Header image courtesy of NASA.
*This article, written by Jennifer La Grassa, was originally published by CBC News on August 4, 2023. *
