Data from countries with consistently poor air quality suggest there could also be a risk of longer term effects to our eyes, particularly with prolonged exposure to bushfire smoke.

Although P2/N95 masks can protect us from inhaling harmful particles, unfortunately they can't protect our eyes.

But there are certain things you can do to minimise irritation and the risk of any longer term effects.

The eye's surface is continuously exposed to the environment, except when our eyes are shut when we sleep.

Bushfire smoke contains dust, fumes (such as carbon monoxide and nitrogen oxides), and tiny particles called PM10 and PM2.5.

When the smoke comes into contact with our eyes, the fumes and small particles dissolve into our tears and coat the eye's surface. In some people, this can trigger inflammation, and therefore irritation.

The presence of a marker called matrix metalloproteinase-9, or MMP-9, indicates the eye is inflamed.

During periods of poor air quality from bushfires in the United States, MMP-9 was present in the eyes of more people than it ordinarily would be.

We know very little about how pollution from bushfire smoke might affect our eyes over the longer term, or what damage repeated or chronic exposure might do.

But we do know people who live in areas with high levels of air pollution, such as China, are three to four times more likely to develop dry eye.

Dry eye is a condition where a person doesn't have enough tears or they are of such poor quality they don't lubricate and nourish the eye. We need high quality tears to maintain the health of the front surface of the eye and provide clear vision.

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For people who already have dry eyes - often older people - poor air quality may increase the damage. The smoke and pollution may cause intense stinging and a feeling of grittiness to the point they can barely open their eyes.

While dry eye is a result of damage to the surface of the eyes, it's also possible pollutants entering the blood stream after we breathe them in could affect the blood supply to the eye. This in turn could damage the fine vessels within the eye itself.

Research has suggested high levels of air pollution in Taiwan may increase the risk of age-related macular degeneration, which could be an example of this.

We need more research into the long-term effects on our eyes of prolonged poor air quality, particularly from bushfire smoke. But what we do know suggests it's possible bushfire smoke could be causing subtle damage to the eyes, even in people without any symptoms.