Why winter makes dry eye worse
If your eyes feel fine in the summer but miserable by January, you are not imagining it. Canadian winters create a combination of environmental factors that stress the tear film from every angle.
Forced-air heating
This is the biggest factor. Central furnaces and baseboard heaters reduce indoor humidity to as low as 15 to 25 percent during heating season. A healthy tear film needs ambient humidity in the 30 to 50 percent range to maintain stability. Below that, tears evaporate faster than your glands can replace them.
The effect is cumulative. By the time you have been running your furnace for a few weeks, the tear film is under constant strain - especially if you also spend hours at a screen, which reduces your blink rate.
Cold outdoor air
Cold air holds less moisture than warm air. Walking outside in a Toronto winter exposes your eyes to air that is both cold and dry. Wind compounds the effect by increasing evaporation directly off the eye surface. Patients who commute on foot or by bike notice this the most.
Temperature transitions
Moving between a heated building and freezing outdoor air - multiple times a day - causes rapid shifts in the environment around your eyes. The tear film does not adjust instantly, and these transitions can trigger reflex tearing, blurred vision, or stinging that lasts several minutes each time.
What you can do at home
Run a humidifier
A room humidifier in your bedroom and workspace is the single most effective environmental change during heating season. Aim for 30 to 50 percent relative humidity. An inexpensive hygrometer lets you monitor the level - most heated Canadian homes are well below 30 percent by December.
Adjust your heating
Avoid sitting or sleeping directly in the path of heating vents. If your home has forced-air, partially closing the vent in your bedroom can reduce overnight drying. Car heater vents aimed at your face are another common trigger - direct them downward toward your body instead.
Use the right drops
Preservative-free artificial tears used regularly throughout the day help supplement what the tear film is losing to evaporation. During winter, using drops proactively - before symptoms peak - is more effective than waiting until your eyes are already irritated.
For overnight relief, a preservative-free lubricating eye ointment applied at bedtime coats the eye surface while you sleep. This is especially helpful if you wake up with gritty, sticky, or blurry eyes.
Stay hydrated
Systemic hydration matters. Tear production depends on adequate overall fluid intake. In winter, people tend to drink less water than in summer - make a point to keep intake consistent.
Protect your eyes outdoors
Wraparound sunglasses or close-fitting frames reduce wind exposure and cold air contact with the eye surface. If you commute on foot or spend significant time outdoors, this is a practical step that makes a noticeable difference.
When home measures are not enough
Environmental changes and artificial tears manage the seasonal component for many patients. But for some, winter simply tips the balance on an underlying dry eye condition that was borderline the rest of the year.
Signs that you need a clinical assessment rather than more drops:
- Symptoms that persist despite running a humidifier and using drops regularly
- Dry eye that gets worse every winter and takes longer to resolve in spring
- Blurred vision that fluctuates through the day, especially after blinking
- Significant redness, pain, or a foreign body sensation
- Contact lenses that become uncomfortable or impossible to wear by midwinter
These patterns often point to meibomian gland dysfunction - the oil glands in the eyelids are not producing enough lipid to stabilize the tear film, and winter’s low humidity removes the last margin of tolerance. This is a structural problem that environmental changes alone will not fix.
How we assess and treat winter dry eye flares
At Spadina Optometry in downtown Toronto, we see a predictable increase in dry eye complaints from November through March. Our approach is to determine whether the winter flare is purely environmental or whether it is exposing an underlying condition that needs treatment year-round.
A structured dry eye assessment may include:
- Meibography - infrared imaging of the meibomian glands to assess structure and detect gland dropout
- Tear film evaluation - assessing tear quality, stability, and evaporation rate
- Eyelid margin assessment - checking for inflammation, blocked glands, or blepharitis
- Symptom scoring - structured intake to identify triggers, patterns, and severity
Based on the findings, treatment may range from optimized drop regimens and lid hygiene to TempSure Envi thermal radiofrequency treatment for significant meibomian gland dysfunction.
The goal is not just to get through the winter - it is to identify and treat the root cause so that next winter is better than this one.
Related
- Dry eye disease - causes, types, and treatment - the full overview
- What is meibography? - how we image the meibomian glands
- TempSure Envi for dry eye - thermal radiofrequency treatment for MGD
- Light therapy for dry eye and blepharitis - how red and blue light are being studied for MGD
- Spring allergies vs dry eye - telling them apart when seasons change
- Digital eye strain and blue light glasses - screen work compounds dry eye symptoms
Common questions
- Is dry eye worse in winter?
- Yes. Dry eye symptoms typically worsen in Canadian winters. Forced-air heating reduces indoor humidity to as low as 15 to 25 percent, well below the 30 to 50 percent range that supports a stable tear film. Cold outdoor air holds less moisture, and wind increases tear evaporation. The constant transition between heated interiors and cold outdoor air also disrupts the tear film. At Spadina Optometry in downtown Toronto, we see a significant increase in dry eye complaints between November and March.
- Does indoor heating cause dry eyes?
- Indoor heating is one of the most common environmental triggers for dry eye in Canada. Forced-air furnaces circulate warm, dry air that reduces indoor humidity and increases tear film evaporation. Sitting near heating vents, sleeping in a heated bedroom without humidification, and working in offices with central HVAC all contribute. A room humidifier that maintains 30 to 50 percent relative humidity can make a meaningful difference during heating season.
- What helps with dry eyes in winter?
- Use a room humidifier to maintain indoor humidity between 30 and 50 percent. Avoid sitting directly in the path of heating vents or car heater vents aimed at your face. Use preservative-free artificial tears throughout the day, and consider a lubricating eye ointment at bedtime if you wake up with dry, irritated eyes. Drink plenty of water and take regular breaks from screen work. If symptoms persist despite these steps, book a dry eye assessment - the seasonal flare may be unmasking an underlying condition like meibomian gland dysfunction that needs clinical treatment.
- Why do my eyes feel worse in the morning during winter?
- Sleeping in a heated room with low humidity dries out the tear film overnight, especially if your eyelids do not fully close during sleep (a condition called nocturnal lagophthalmos, which is more common than most people realize). The result is eyes that feel gritty, sticky, or blurry upon waking. A bedroom humidifier and a preservative-free lubricating ointment applied at bedtime can help. If morning symptoms are persistent, an eye exam can rule out underlying causes.
- Should I see an optometrist for winter dry eye?
- If your dry eye symptoms are mild and respond to humidification and artificial tears, you may not need a clinical visit for the seasonal component alone. But if symptoms persist despite environmental changes, get worse every winter, or include blurred vision, significant redness, or pain, book a dry eye assessment. Seasonal flare-ups often unmask meibomian gland dysfunction or aqueous deficiency that was borderline during the rest of the year. At Spadina Optometry in downtown Toronto, we use meibography and tear film evaluation to identify the root cause and build a treatment plan that works year-round.
Dry eyes getting worse this winter?
We can assess your tear film and meibomian gland health and recommend a plan that gets ahead of the seasonal flare - not just manages the symptoms.
Prefer to talk first? Call or text us at 416-703-2797.
Spadina Optometry has cared for downtown Toronto patients since 2002 — an independent practice where the same team knows your eyes year after year.
Last reviewed: August 21, 2026