Allergic conjunctivitis

Allergic conjunctivitis is an inflammation of the conjunctiva, the mucous membrane that lines the inside of your eyelids and the white part of your eye. The inflammation occurs because your immune system reacts to a substance that your body perceives as a threat, such as pollen, house dust mites, mould spores or animal hair. Upon contact with such an allergen, your body produces histamine, which leads to the typical symptoms.

The condition occurs in two main forms. Seasonal allergic conjunctivitis mainly occurs in spring and summer, often caused by pollen from trees, grasses and weeds. Chronic or perennial allergic conjunctivitis lasts all year round and is usually caused by house dust mites, mould or pets.

You can recognise allergic conjunctivitis by red, itchy eyes that water. Your eyes often feel a burning sensation or are irritated, and sometimes your eyelids swell up. The symptoms usually affect both eyes at the same time and are often accompanied by other allergic symptoms such as sneezing, a runny nose or a blocked nose.

Allergic conjunctivitis is not contagious, unlike infectious forms of conjunctivitis. However, the symptoms can affect your day-to-day life, particularly if you wear contact lenses or spend a lot of time working in front of a screen.

Contact lenses and allergic conjunctivitis

If you wear contact lenses and suffer from allergic conjunctivitis, your lenses may feel uncomfortable. Allergens can build up on the lens surface, making the symptoms worse. Your eye may also be particularly sensitive during an allergic reaction, making it more difficult to wear lenses.

Some contact lens wearers opt for daily disposable lenses during the pollen season, as you replace them every day, meaning fewer allergens can build up on them. Other options include replacing your lenses more frequently than usual or temporarily switching to glasses. Discuss with your optician or optometrist what works best in your situation.

Irritation and rinsing the eye

Allergic irritation can cause the surface of the eye to feel sore. Some people rinse their eyes with a sterile saline solution or use moisturising eye drops. These are designed to moisturise and rinse the surface of the eye; they do not treat the allergy itself.

When to see an optician, optometrist or ophthalmologist

If you are experiencing red, itchy or watery eyes and are unsure of the cause, have them assessed by your optician, optometrist or ophthalmologist. They can determine whether it is an allergic reaction or another eye condition. It is also advisable to get in touch if your symptoms persist, worsen or are accompanied by pain or impaired vision.

If allergic conjunctivitis is confirmed, an ophthalmologist or GP may, if necessary, prescribe medication, such as antihistamine eye drops or mast cell stabilisers, to reduce the allergic reaction. Always follow the advice and dosage given by your doctor or pharmacist.