Anyone who lived in Westlake Village, Thousand Oaks, or Agoura Hills during the November 2018 Woolsey Fire remembers the smoke and ash, and how many people’s eyes burned while it lingered. Fire season is a fact of life in the Conejo Valley, and smoke can drift in from fires far away. Many patients ask me whether smoke actually harms the eyes or just makes them feel bad. A carefully controlled study gives a clearer answer.
How the study was done
Researchers from the University of New South Wales and the University of Tasmania burned woody bush fuels in an enclosed fire laboratory. Eighteen adults aged 20 to 63, wearing respirators to protect their lungs, sat about 1.5 meters from the burn for 15 minutes. Fine particle levels averaged 1,903 micrograms per cubic meter, very heavy smoke. The team examined the eye surface and collected tears before and after.
What changed after just 15 minutes
- Eye symptoms increased.
- Staining of the eye surface, a sign of surface cell damage, increased.
- Redness of the white of the eye near the cornea and inside the lids increased, and the inner lids became rougher.
- Tear breakup time shortened, meaning the tear film became less stable.
- Most participants had higher levels of interleukin-1 beta, an inflammation marker, in their tears.
The authors concluded that short-term wildfire smoke directly and adversely affects the eye surface. This was a small study with one short, intense exposure, so it does not tell us about long smoky weeks, but it shows that the irritation is real inflammation, not just a feeling.
What I recommend on smoky days
- Check air quality before a lakeside walk or a hike in the Santa Monica Mountains, and stay indoors with windows closed when it is poor.
- Run home or car air on recirculate and use a HEPA filter if you have one.
- Use preservative-free artificial tears several times a day to rinse and soothe the eye surface.
- Wear glasses or wraparound sunglasses outdoors; contact lens wearers may be more comfortable switching to glasses until the air clears.
- Do not rub; ash is gritty. Rinse with clean water or saline instead.
- If redness, pain, light sensitivity, or blurred vision persist after the air clears, schedule an exam.
Our office is at 31824 Village Center Rd, Suite F, Westlake Village, CA 91361, a short drive for commuters on the 101 from Thousand Oaks and Agoura Hills; call (805) 230-2126. For more eye-health reading, see pieineye.com.
Source: Wildfire Smoke Induces Eye Surface Inflammation and Tear Film Changes in a Human Experimental Model (Translational Vision Science & Technology (PubMed), 09/2025). This article is an educational summary written by Khanna Vision Institute and is not a substitute for medical advice.