Eyes that become watery, itchy, or red could be related to allergen exposure. While certain types of eye drops may help, other allergy-specific treatments may be needed to fully manage symptoms.

An allergy is a type of hypersensitivity reaction in the body. It occurs when your immune system mistakes typically harmless particles as potential threats, setting off an immune response. Histamines, chemicals released by the body during an allergic reaction, cause itchiness and inflammation.

When an allergen affects your eyes, either from direct exposure or as part of a full-body response, your eyes may increase tear production as a way to flush out allergens and soothe related irritation. Eye allergies are known as ocular allergies or allergic conjunctivitis.

Allergy-related eye discomfort can come from a variety of sources, including pollen, pet dander, mold, and dust. It’s unclear why certain people experience allergies when others don’t.

When allergies cause itchy, watery, red, or puffy eyes, different over-the-counter (OTC) products and prescription therapies can help.

Artificial tears are OTC products designed to help lubricate the eyes. They’re generally used to treat dry eyes, but they can also help flush out allergens.

Artificial tears won’t stop an allergic reaction because they don’t contain antihistamine ingredients. But if used promptly, they may help lessen an allergic response by helping remove the irritant.

Some artificial tear products contain preservatives to help prevent bacterial growth in the droppers. Preservatives can cause their own form of eye irritation, especially with prolonged or frequent use. Some people may also have allergic reactions to different preservatives.

When selecting artificial tears, consider preservative-free options. Products can be refrigerated to help increase their soothing effect on the eyes.

Antihistamine eye drops can be purchased over the counter, or a doctor can prescribe them in stronger formulations. They contain antihistamines, chemicals that bind to the same receptor sites in the body as histamine, blocking its effects.

Different antihistamines provide varying levels of relief. In eye drop form, they may only help for a few hours at a time. They might need to be used multiple times each day.

Many OTC and prescription antihistamine drops also contain mast cell stabilizers. Unlike antihistamines, which only block the effects of histamine, mast cell stabilizers work to prevent histamine.

Mast cells are a part of your body’s allergic response. With mast cell stabilizers, the mast cells are less likely to become activated by allergens and less likely to release inflammatory chemicals like histamine.

When you have a stuffy nose, you might reach for a nasal decongestant. Eye decongestants are also available and they work similarly, constricting the blood vessels.

In your nose, blood vessel constriction helps decrease swelling in the lining of your nasal cavity by restricting blood flow. In your eyes, blood vessel constriction makes blood vessels appear less visible, reducing redness.

Decongestant eye drops don’t prevent or stop an allergic reaction. They may help reduce redness from eye allergies, but they’re not appropriate for long-term use.

The American College of Allergy, Asthma & Immunology (ACAAI) recommends avoiding use of decongestant eye drops for more than several days. Prolonged use may cause rebound redness, a condition where the vessels of the eyes dilate beyond their regular size after the medication wears off.

Oral antihistamines, available by prescription or over the counter, may also help relieve eye allergy-related discomfort. Oral antihistamines block the effects of histamines on a systemic, or whole body, level.

Your doctor may recommend adding or primarily using an oral antihistamine for several reasons.

Not all allergic reactions that cause eye symptoms are related to direct exposure to an allergen. Histamine release from allergen exposure in other areas of the body can also affect the eyes, causing symptoms.

Oral antihistamines may offer longer relief than eye drops. Many can work in the body for 12–24 hours. If you’re not able to continually apply antihistamine eye drops, oral medications can offer a reliable alternative.

Adding an oral antihistamine to antihistamine eye drops may offer more complete management of allergic reactions throughout the body, even if they originate in the eyes.

Allergy shots, also known as allergen immunotherapy, work much like a vaccine. They expose your body to small amounts of an allergen as a way of promoting tolerance and building up immunity.

Allergy shots aren’t used to immediately relieve the symptoms of allergies. In other words, if you’re experiencing an eye allergic reaction, your doctor won’t give you an allergy injection to make those symptoms go away.

Instead, allergy shots help ease the symptoms of eye allergies over time. The more you’re exposed to manageable amounts of an allergen, the more your body becomes able to recognize that it isn’t a threat when the immune system encounters it.

Allergy shots work differently for everyone. They may not be as effective if you’re exposed to high levels of the allergen in your environment or if you’re allergic to multiple irritants.

If you have severe eye allergy-related discomfort, your doctor may prescribe other types of medications in addition to antihistamines.

Nonsteroidal anti-inflammatory drugs in eye drop or oral forms can help relieve the pain and discomfort associated with eye allergies by reducing inflammation.

Corticosteroids, available by prescription in eye or drop oral forms, can help suppress the immune response that causes allergies. They work to prevent the production of specific inflammatory substances in the body that contribute to allergy discomfort.

When it comes to eye allergies, prevention is key. Taking steps to avoid exposure to any known allergens can help reduce your need for treatment.

According to the ACAAI, here are some tips for avoiding exposure:

  • Stay indoors as much as possible if you’re allergic to outdoor allergens.
  • Avoid using fans that may circulate allergens.
  • Don’t touch your eyes with unwashed hands.
  • Wear glasses when outside to protect your eyes.
  • Use air conditioning in buildings and cars instead of opening windows.
  • Avoid dry dusting or sweeping.
  • Wash bedding frequently in water temperatures of at least 130°F (54°C).
  • Use mite-proof linens.
  • Keep indoor humidity levels between 30% and 50% to limit mold growth.
  • Keep pets out of the bedroom if you’re allergic to their dander.
  • Wash your hands immediately after touching a known allergen.
  • Change or shower and wash your clothes after being outside your home.

Eye allergy-related discomfort comes from an immune response that produces redness, inflammation, and itching in the eyes.

While eye drops, oral medications, and allergy shots may all help relieve the symptoms of eye allergies, not every product is appropriate for long-term use or beneficial for addressing the underlying causes of allergies.

Because improper eye drop use can worsen some eye conditions, it’s important to speak with an eye doctor or allergist before trying a new product.