Why Is Dry Eye Worse in Winter? What Toronto Patients Can Do

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
• Spring allergies vs dry eye – telling them apart when seasons change
• Digital eye strain and blue light glasses – screen work compounds dry eye symptoms