When you inhale an allergen such as pollen, your nose may run and you might start sneezing. That’s your body jumping into action to eliminate the irritant.

Allergies work the same way in the eyes. When an allergen gets into your eyes, you can develop uncomfortable symptoms, including itchy, watery eyes. As many as 40% of people struggle with eye allergies, and the rates are increasing.

It’s not completely clear what’s behind the increasing numbers. It’s thought that a combination of air pollution, climate change, and poor diet are likely culprits.

Here’s everything you need to know about the science behind eye allergies, their telltale symptoms, and doctor-approved ways to find relief.

Have questions about your vision or eye health? Reach out to your America’s Best optometrist, who is an important part of your care team. Click here to make an appointment.

What are eye allergies?

Ocular allergies, commonly called eye allergies, are simply allergies that affect your eyes.

A part of your eye, called the conjunctiva, functions like a clear cover similar to what you might place over a book to prevent damage. The thin, transparent membrane protects the white of your eye as well as the inside of your eyelid, lubricating these areas and stopping irritants from getting inside. It’s the first line of defense against the hazards of the outside world — and it’s also the part of your eye most affected by them.

When allergens such as pollen land on this part of the eye, they can trigger an immune system response.

“The mast cells in your eye release histamine, causing symptoms like redness, puffiness, tearing, and itchiness,” says Anthony Giallombardo, O.D., an optometrist at America’s Best Contacts & Eyeglasses in Toms River, New Jersey.

Recommended reading: 8 Sneaky Causes of Itchy Eyes (That Have Nothing to Do with Pollen)

What triggers eye allergies?

Histamine isn’t all bad. This inflammatory signaling molecule is usually protective, especially when your eye is under attack by germs. Among other reactions, histamine makes blood vessels porous, allowing immune cells to find and attack germs.

But unlike germs, allergens aren’t harmful. In certain people, however, the immune system has become sensitized to them, leading to an unnecessary reaction and unpleasant symptoms.

Common triggers include:

• Outdoor seasonal allergens such as pollen from grass and treesI
• Indoor allergens from pet dander (dead skin cells), mold, dust mites, cockroaches, or rodents
• Chemicals found in laundry detergent, makeup, and lotions

What are the symptoms of eye allergies?

The flood of histamines in your eyes can lead to uncomfortable symptoms, such as:

• Burning
• Itchiness
• Redness
• Swelling, especially in the eyelid
• Tearing

How are eye allergies diagnosed?

For an accurate diagnosis, it’s important to consult your optometrist. That’s because common eye allergy symptoms overlap with the symptoms of other eye problems, such as dry eye and bacterial conjunctivitis, says Dr. Giallombardo. If you treat yourself for allergies but have dry eyes, your symptoms will likely persist or worsen, he says.

To diagnose eye allergies, your optometrist will do a thorough eye exam. They will check to see whether:

Both eyes are affected. “Typically, allergies affect both eyes that are exposed to the allergen,” says Dr. Giallombardo. “Bacterial conjunctivitis (pink eye) usually affects just one eye.”

You have raised bumps inside your eyelid. “We will look at the inside of your lower eyelid,” says Dr. Giallombardo. “In people with allergies, we find raised bumps called papillae.” These bumps are from tissue that has swelled in response to an allergen.

Recommended reading: Does My Child Have Pink Eye or an Eye Allergy Flare-up? Ask an Optometrist

Who gets eye allergies?

Eye allergies are more common in people with other allergies, such as allergic rhinitis (inflammation of the nasal passageways), asthma, food allergies, and skin conditions such as eczema.

People who wear contact lenses can be especially vulnerable. If allergens get stuck to your contacts, they can trigger an allergic reaction each time you insert your lenses. (Keep reading for ways to prevent this problem.)

How can I treat my eye allergies?

When your eyes are itchy and watery, you’re desperate to find relief. Luckily, there are some simple ways to ward off unpleasant eye allergy symptoms. These include:

Cold compresses. Wet a washcloth with cold water and ring it out over the sink. Then place the washcloth over your closed eyes. It’s a good idea to do this once in the morning and then again later in the day, says Dr. Giallombardo. The coolness from the compress will constrict your blood vessels, helping to reduce swelling and redness. What’s more, resting with your eyes closed allows your eyes to flush out the allergens.

Over-the-counter antihistamine eye drops. The brands Pataday, Zaditor, and Lastacaft contain two lines of defense. The first, mast cell stabilizers, prevent the mast cells in your eyes from releasing histamine. The second line of defense is an antihistamine, which blocks the effects of histamines that may have been released. “They’re most effective when taken before you come in contact with an allergen, such as a week before your seasonal allergies usually start,” says Dr. Giallombardo.

Over-the-counter allergy medicine. Claritin, Allegra, and other oral antihistamines help block the release of histamine in the eyes and elsewhere in the body. As a result, they can help treat a stuffy nose and eye allergy symptoms.

Artificial tears. Commonly used to treat dry eye, these lubricants can help to flush allergens from your eyes. Look for ones that say “allergy eye drops” on the bottle.

Can I prevent eye allergies?

Yes. Like all allergies, the best prevention for eye allergies is avoiding your triggers.

That, however, requires knowing which allergens are affecting your eyes. Pinpointing the specific allergens can be like solving a mystery, says Dr. Giallombardo.

He asks his patients the following questions, especially if their allergy symptoms have recently developed.

Did you recently:

• Change your detergent? If so, you may be allergic to one of its chemicals. Once the chemical is on your sheets (especially your pillowcase), it can get in your eyes, triggering symptoms.
• Start using a new soap, shampoo, or face wash? Tiny amounts are possibly getting in your eyes when you shower or wash your face.
• Start using different makeup, such as eyeliner or mascara? Tiny particles might be getting in your eyes, causing irritation.
• Get a new pet? You might be allergic to its dander.
• Move? Your new location may have different trees, mold, and other indoor or outdoor allergens.

Whenever possible, stop using products that irritate your eyes. However, avoidance may be impossible, especially when it comes to a pet or place of residence. In that case, try the following:

• Use eye drops before allergies strike. If you know you will be exposed — for example, at a friend’s house where there’s a cat — use mast cell stabilizing drops (such as Pataday) immediately beforehand. “A lot of people start after the symptoms hit, when the drops aren’t as effective,” says Dr. Giallombardo.
• Shower at night. Pollen can cling to your hair, clothing, and skin, so rinse off each night to reduce your chance of waking up with puffy eyes.
• Lower the humidity levels in your home to between 30% and 50%. That can help prevent allergy-triggering molds. You can use a dehumidifier to reduce humidity in your home, if it’s too high.
• Don’t rub your eyes. Rubbing your eyes provides quick relief, but it comes at a cost. It will trigger the release of more histamine, which causes more inflammation.

I wear contacts. What do I need to know about eye allergies?

Airborne allergens can land on the surface of your contact lenses, spelling trouble for people with eye allergies.

“When these tiny pollen particles stick to the lens, they’re difficult to completely clean off,” says Dr. Giallombardo. “When you put the contact back in, you retrigger your allergies.”

To avoid this problem, you’ve got a few options.

Wear glasses instead. This is especially helpful during allergy season or whenever you know you’ll be exposed to an allergen. That way, the allergens will land on the lens of your glasses, which can be washed, and not on the contact lens in your eye.

Switch to dailies. Daily contact lenses are worn once and discarded at the end of the day. That means you don’t have to worry about carefully cleaning and reinserting them.

Use eye drops before inserting your lenses. Using the dual-purpose eye drops mentioned above ahead of time can help prevent allergy symptoms. After using the drops, wait 15 minutes before inserting your lenses.

The bottom line: When you work closely with your eye doctor to stay on top of your eye allergies, the symptoms can be well controlled — so you can go about your day with comfortable vision.

Medically reviewed by Anthony Giallombardo, O.D.

See our sources:
Allergic conjunctivitis overview: Allergy, Asthma & Clinical Immunology
Prevalence of eye allergies: Allergology International
Link between air pollution and eye allergies: Scientific Reports
Link between climate change and eye allergies: Community Eye Health