07.04.2025

Eye allergies: when our eyes overreact

Do you ever get red, itchy or watery eyes, especially in spring or when there is dust in the air? These symptoms may be a sign of ocular allergy, a common disorder that affects 15 to 20 % of the world's population every year. Almost half of allergy sufferers experience ocular symptoms, which can have a significant impact on quality of life.

(by Med. pract. Victoire Hurand)

Our eyes are particularly vulnerable to allergens, which are invisible airborne substances such as pollen, dust mites and animal hair. In contact with the conjunctiva (the thin membrane that covers the eye and the inside of the eyelids), these particles trigger an excessive reaction of the immune system, causing eye redness, itching, watering, swelling of the eyelids, and sometimes increased sensitivity to light (photophobia).

Although mild, these symptoms can be very troublesome in everyday life. Why do our eyes react in this way? What are the treatments and means of prevention? Let's examine the situation together.

Why do our eyes react?

Eye allergy is an excessive immune reaction to a normally harmless substance: pollen, dust mites, animal hair or dust, etc. When these allergens come into contact with the conjunctiva, the body mistakenly perceives them as a threat. It then triggers an inflammatory response by releasing histamine (secreted by mast cells) and other chemical substances responsible for the symptoms: eye redness, eyelid swelling and itching, etc.

The allergy mechanism always follows the same pattern. On first contact with an allergen, the body becomes «sensitive» but does not yet react. However, on subsequent exposures, it triggers an immediate and sometimes intense reaction.

The most common form of eye allergy is related to hay fever, a reaction to seasonal pollens. In this case, the eye symptoms are often accompanied by sneezing and a runny nose. About 20 % of allergy sufferers have these eye symptoms, which are often associated with other allergies (food, asthma, eczema, etc.).

At Swiss Visio, we offer consultations and surgeries in an excellent environment for all ocular pathologies except oncology. Our 22 centres provide fast and personalised care in a trustworthy environment and we do our utmost to offer appropriate medical care.

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Different clinical forms

Eye allergies manifest themselves in several clinical forms, some benign and seasonal, while others can be more severe and persistent.

Seasonal allergic conjunctivitis

Also known as «hay fever conjunctivitis», it is caused by exposure to tree, weed or grass pollen, as well as airborne mould spores. It mainly appears in spring, late summer or autumn, depending on the pollen cycle. The symptoms disappear in winter when exposure to these allergens decreases.

Perennial allergic conjunctivitis

Unlike seasonal conjunctivitis, this form persists throughout the year. It is triggered by indoor allergens such as dust mites, animal hair and certain moulds. The symptoms can be chronic, with more intense flare-ups in case of prolonged exposure.

Vernal keratoconjunctivitis

This is a more severe form of ocular allergy, mainly affecting boys aged 5 to 15 with a history of eczema or asthma. It occurs every spring when the light increases and can develop into corneal complications such as corneal ulcers.

Atopic keratoconjunctivitis

This chronic and severe form is often associated with atopic dermatitis. It causes persistent ocular inflammation, which can lead to corneal damage and increase the risk of ophthalmological complications. Rigorous management is essential due to its potential impact on vision.

Giant papillary conjunctivitis

Giant papillary conjunctivitis: Often associated with wearing contact lenses, or with the prolonged presence of a foreign object.

What could allergies be confused with?

Eye allergies share symptoms with other eye conditions. Redness, watering and itching are not always synonymous with allergy. An ophthalmological examination is therefore essential to make the correct diagnosis and avoid confusion with:

Infectious conjunctivitis (viral or bacterial)

Often accompanied by thick secretions and an infectious context (cold, fever), it can affect several people in the surrounding area.

Snow blindness

Corneal burn due to intense exposure to UV rays emitted by the sun, especially in the mountains without suitable sunglasses.

A corneal abscess in contact lens wearers

Linked to poor contact lens hygiene, it causes intense pain and a loss of vision.

Irritation due to a toxic substance

Smoke, chemicals or pollution can cause similar symptoms.

Prevention is better than cure: here is what to do

1. Limit exposure to allergens

If you are allergic to pollen, it is advisable to consult the pollen calendar, as pollination periods vary each year depending on the weather. Wear sunglasses and a hat when you go out. Air your home early in the morning or late in the evening, when the pollen concentration is lower. Rinse your eyes with saline solution after each outing and wash your hair to avoid contaminating the bedding.

If you are allergic to dust mites, wash the bedding at 60°C every week. Avoid carpets, rugs and soft toys in the bedroom. Use anti-dust mite covers and air the room daily. Maintain a moderate temperature (18-19°C) to limit their proliferation.

In case of allergy to animal hair, avoid direct contact with the animal and wash your hands after petting it. Clean your home regularly and air the rooms.

2. Avoid rubbing your eyes

It may seem harmless, but rubbing your eyes makes the inflammation worse and can, in the long term, weaken the cornea, leading to keratoconus (irreversible progressive deformation of the cornea), which causes a decrease in vision and irregular astigmatism.

How can I alleviate the symptoms during the allergy period?

There are various solutions to reduce the discomfort:

Generous eye wash with saline solution or 0.9% NaCl: removes allergens from the surface of the eye, dilutes inflammatory factors and soothes irritation.
Artificial tears: moisturise and reduce irritation of the ocular surface.
Antihistamine eye drops: block the action of histamine and reduce symptoms.
Mast cell stabilising eye drops (e.g. sodium cromoglycate): prevent the release of histamine by mast cells and allergic attacks.

Corticosteroid eye drops (prescription only): effective in cases of severe inflammation, but use with caution due to potential side effects (increased intraocular pressure, cataracts, delayed healing, dependency, etc.).
Oral antihistamines: useful in cases of allergy affecting the respiratory tract or the skin.
Allergy test: to identify the responsible allergen. A negative test does not exclude an allergy, as some forms are exclusively ocular. Desensitisation may be considered in some cases.

Depending on the severity of the symptoms, a multidisciplinary approach involving ophthalmologists, dermatologists, ENT specialists and allergists may be necessary in order to offer the patient personalised treatment.

Conclusion

Eye allergies, although common and debilitating, can be controlled with preventive measures and appropriate treatments. If symptoms persist or become troublesome, do not hesitate to consult a specialist.

With the right reflexes, it is possible to have comfortable eyes even during allergy season!

Our ophthalmology specialist

Med. pract. Victoire Hurand

Victoire Hurand, MD is a specialist in ophthalmology and works as a head of clinic at Swiss Visio. She completed a successful career in ophthalmology and ophthalmic surgery at the University Hospitals of Dijon and Beaune (France) before deciding to specialise more deeply within the Swiss Visio network. Always striving to perfect her skills, she specialised in refractive surgery at the Fondation Rothschild, obtained several inter-university diplomas (cornea, contactology, medical retina, refractive surgery and ocular inflammation) as well as a research master's degree and is part of the European Board of Ophthalmology (EBOD).

Victoire Hurand welcomes her patients, including emergencies, in the ophthalmological consultation at Montchoisi, Chavannes, and Palézieux village.