Do I have dry eye or allergies?

Allergic eyes itch, and the urge to rub them is hard to resist. They often come with a runny nose or sneezing, they may swell slightly, and they are usually both affected equally. The pattern is frequently seasonal — worse in spring and through pollen season — or tied to an obvious trigger such as a cat.

Dry eye burns, stings and feels gritty rather than itchy. It builds through the day, is worse on screens and in wind, and often includes watering and fluctuating vision.

Allergy inflames the surface of the eye and the lid margin, which interferes with the oil glands. Rubbing makes that worse. Meanwhile, antihistamines — the usual treatment for allergy — reduce tear production, which deepens dryness. It is a loop that is easy to fall into and hard to think your way out of from the outside.

Treating only the allergy in someone whose glands are blocked tends to disappoint. So does treating only the dryness in someone in the middle of pollen season.

For allergy, the sensible first steps are the ones we give in clinic: preservative-free artificial tears to flush allergens out, a cool compress over closed lids to settle itch and swelling, keeping windows shut when pollen counts are high, and sunglasses outdoors. Antihistamine or mast cell stabiliser drops help too — ask us or your pharmacist which suits you.

The one thing to resist is rubbing. It feels like relief, but it releases more histamine and can damage delicate tissue, so the itch comes back worse.

The assessment looks at the lid margin, the glands and the tear film, alongside the history — when it is worse, what you have tried, what medication you are taking. Often the answer is that both are present, and the useful question becomes which one to address first.

That is a conversation worth having before spending money on either.