Eye allergy

Eye allergies (also known as allergic conjunctivitis) are common and cause symptoms such as redness, itchiness, and swollen, puffy eyes. Eye allergies happen when the body’s immune system responds to triggers in the environment, like pollen and dust. The eyes produce histamine to fight the allergen, which causes the eyelids and conjunctiva (the mucous lining around the eye) to become inflamed.

Unlike conjunctivitis caused by viruses or bacteria, allergic conjunctivitis isn’t contagious, but it can be annoying to live with. You can prevent symptoms by trying to avoid triggers you know you’re allergic to. But this isn’t always possible, especially with allergens such as pollen. Treatments including eye drops can relieve symptoms, and other options may be available if your allergy is severe and persistent.

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Eye allergy symptoms

Common symptoms of eye allergies include red eyes, itchiness, watery eyes, swelling, discomfort and being more sensitive to light. In severe cases, if the cornea becomes inflamed, your vision can be affected. Most people experience more than one symptom at a time. It’s common to have other symptoms, such as a runny nose, sneezing, headache, and sore throat.

Allergy eye symptoms happen when the eyelid and conjunctiva, the mucous membrane on the surface of the eye, become inflamed. This is due to the body producing histamine as an immune response to allergens.

Eye allergy treatment

The only way to prevent allergy symptoms is to limit your exposure to known allergens. For example, pollen forecasts can tell you about high pollen counts when you might want to limit time outdoors. Realistically though, it’s not always easy to prevent exposure, and treatments such as eye drops can relieve your symptoms.

In severe cases, long-term immunotherapy treatment may be an option. This treatment exposes your body to allergens in very small amounts over a very long time to reduce your body’s reaction to the allergen. You would be referred to an allergist by your GP for assessment and treatment.

There are several types of eye drops to relieve eye allergy symptoms:

Artificial tears (lubricant eye drops) can clear allergens from the eye and add moisture to dry eyes. You can use artificial tears multiple times a day, and you can buy them over the counter without a prescription.

Antihistamine eye drops block the histamine that causes inflammation and irritation, relieving itchiness and other symptoms. You can buy them over the counter and get them on prescription.

Non-steroidal anti-inflammatory drugs are available in eye drops on prescription.

Some people need corticosteroid eye drops for severe allergies. As these have side effects, they are only available on prescription and for short-term use.

Decongestant eye drops reduce redness by shrinking swollen blood vessels. Always read the medicine leaflet as these aren’t for everyone, for example, people with glaucoma.

Eye allergy relief

As well as medicines, there are other ways to relieve the symptoms of eye allergies. Try these simple home remedies when you’re having trouble with symptoms:

Stop wearing contact lenses while your eyes are irritated. Allergens can become trapped under contact lenses, making the irritation worse.
Wash your face and eyelids to help clear allergens from your face.
Make a cold compress by soaking a washcloth with cold water and hold it over your closed eyelid. This can help with dryness and irritation.
Tempting though it is, try not to rub your eyes, as rubbing can worsen symptoms.

What causes eye allergies?

Eye allergies happen when the body’s immune system mistakenly treats allergens as harmful and fights them. Mast cells in the eye produce histamine, and it’s this reaction that causes the symptoms of eye allergies. There are indoor and outdoor allergens, and it’s possible to have seasonal allergies (for example, due to pollen) and perennial allergies (for example, caused by dust mites). You’re more likely to develop allergies if both your parents had them.

Allergy to pollen (hayfever) is very common. Eye allergy symptoms caused by pollen are known as seasonal allergic conjunctivitis. Pollen comes not just from flowers but from grasses, trees and weeds. You’re most likely to suffer from a pollen allergy during spring (when tree pollen is most prevalent) and summer (when there are high pollen levels from grass).

It’s hard to avoid an allergic reaction with seasonal allergies because pollen is all around us in the atmosphere. However, you can look at the pollen count forecast in your area and try to limit time outdoors when pollen levels are very high. Keep house and car windows closed, and try wearing wraparound sunglasses when outside to reduce the amount of pollen that comes into contact with your eyes.
Dust and indoor allergens are present all year round, so being allergic to them is sometimes called chronic conjunctivitis or perennial conjunctivitis. House dust contains dust mites which are an allergen.

You can limit exposure to dust mites include using hypoallergenic bedding and washing bedding regularly at higher temperatures. Vacuum regularly and use a damp cloth for dusting.
Several other common allergens can cause eye allergy symptoms. These include:

Pet dander, the flakes of dead skin from animals, commonly cats and dogs, and rabbits and other animals. You can reduce exposure by washing your hands after touching animals. If you have pets you’re allergic to at home, wooden or tile floors can make cleaning easier.

Mould is an allergen for some people. You can limit mould by keeping humid rooms like the kitchen and bathroom well ventilated, cleaning regularly, and using a dehumidifier.

Smoke contains tiny particles that can irritate the eyes, especially those with dry eye syndrome.

Chemicals include chlorine and preservatives in eye drops.

Eyes can also be affected by allergens that don’t come into direct contact with the eye, such as food allergies and insect bites and stings.

Frequently asked questions

Conclusion

Eye allergies are very common, and while it can be hard to avoid the triggers entirely, treatments are widely available to relieve the symptoms. Most people can manage their symptoms with eye drops, but you might need to see a doctor for longer-term support, such as immunotherapy, if you suffer from severe and chronic allergies.

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Medically reviewed by: The Royal College of Ophthalmologists on 28/07/2022

Edited by: Nick Astbury FRCS FRCOphth FRCP
Clinical Associate Professor
LSHTM

The Royal College of Ophthalmologists champions excellence in the practice of ophthalmology and is the only professional membership body for medically qualified ophthalmologists. The RCOphth is unable to offer direct advice to patients. If you’re concerned about the health of your eyes, you should seek medical advice from your GP, optometrist or ophthalmologist.