What eye allergies are
Eye allergies are triggered by the same irritants that cause sneezing, a runny nose and other allergy symptoms. In an allergic reaction the eyes overreact to a substance the body perceives as harmful, producing red, watery, itchy eyes. Many people react to dust with excess tears and mucus, while the same dust is harmless to others. Eye allergies can also be caused by cosmetics or by eye drops used to treat dry eyes; some people react to preservatives, in which case preservative-free products may help.
Airborne allergens are the main cause. Other allergies, such as food allergies, do not usually affect the eyes. Allergies can also be associated with conjunctivitis and asthma. The symptoms are usually easy to recognise: red, watery or itchy eyes, a runny nose and headache are the most common.
An allergy is an overreaction of the immune system to a foreign substance. The reaction occurs when an allergen meets antibodies on the mast cells of the eye. These cells then release chemicals, including histamine, which make tiny blood vessels leak and leave the eyes red and irritated.
Types of eye allergy
Eye allergies are classified by frequency, season, trigger and severity. The main types are:
Atopic conjunctivitis. Often described as the most common allergic eye condition: a hypersensitivity to airborne particles such as dust, animal dander, mites, pollen and mould spores.
Seasonal allergic conjunctivitis. Commonly known as hay fever, and most often seen in the summer season. It causes itching, redness and swelling of the eyelids.
Perennial allergic conjunctivitis. Occurs all year round, is linked with dry eye symptoms and is seen mostly in middle-aged people. Affected individuals may have prominent dark circles under the eyes.
Vernal keratoconjunctivitis. Rare, but can be severe and can lead to corneal complications. It usually occurs in warmer climates and mainly affects children and young adults. Symptoms include a foreign-body sensation, severe itching, sensitivity to light, thick mucus and bumps under the upper eyelids.
Atopic keratoconjunctivitis. Accompanies eczema, allergic rhinitis or asthma, and needs to be treated under a doctor's care because it can threaten eyesight. Inflammation, itching and redness of the eye are seen along with eczema on the eyelids.
Contact lens hypersensitivity. Seen in people who wear contact lenses for vision correction or cosmetic reasons. It is caused by repeated micro-trauma to the cornea, the clear front layer of the eye. Symptoms include redness, itching, mucus and marked discomfort when wearing lenses.
Contact blepharoconjunctivitis. Natural resins in cosmetics, mascara or components of eye medicines can cause hypersensitivity and toxic damage to the eye surface. Preservative-free artificial tears are used in treatment.
Delayed allergy. Airborne chemicals released from rubber or composite compounds, and from certain plants in warm climates, especially in greenhouses, can cause a delayed allergic reaction with eye irritation and inflammation.
Diagnosis
Your doctor first reviews the history of your allergy to establish how often it recurs. Visible signs of conjunctivitis include redness, watery eyes and small bumps inside the eyelids. The following tests may be used to identify the allergy precisely:
- Allergy skin test: the skin is exposed to suspected allergens to observe the body's reaction.
- Blood test: measures the antibodies your body produces in response to allergens.
- Laboratory test: a sample of conjunctival tissue is taken to identify the white blood cells involved.
Treatment
The first step is to avoid the trigger where possible. If you are allergic to dust, keep your home free of dust and dander. For mild symptoms, non-prescription eye drops that relieve itching and redness may be enough. If symptoms are severe, if non-prescription drops do not help, if you are unsure what you are allergic to, or if you cannot avoid the trigger, see a doctor, because you may need stronger medication.
At Spanish Eye Clinic in Dubai, our ophthalmologists help identify the cause of your allergic reaction and prescribe suitable eye drops or oral medication to relieve the symptoms. Identifying triggers, keeping good eye hygiene and using the treatment prescribed can control symptoms in most cases, but allergies tend to recur and ongoing management may be needed.
Frequently asked questions
- Can eye allergies cause blurry vision?
- Yes. Eye allergies can sometimes cause temporary blurry vision because of excess tearing, inflammation and mucus build-up. If blurry vision persists or worsens, see an eye specialist to rule out other conditions.
- How can I tell the difference between eye allergies and an eye infection?
- Eye allergies typically cause redness, itching and watery eyes but not thick discharge or significant pain. Eye infections may produce yellow or green discharge, swelling and discomfort. If symptoms persist, see an eye doctor for a diagnosis.
- Can wearing contact lenses make eye allergies worse?
- Yes. Contact lenses can trap allergens such as pollen and dust and worsen symptoms. During a flare-up, consider switching to glasses or using daily disposable lenses. Preservative-free artificial tears may also help reduce irritation.