If you’re experiencing itchy eyes without an easily identifiable reason, you may have allergies that affect your eyes. Allergies occur when your immune system cannot process something in the environment — or perceives it as harmful and overreacts.

This can happen when foreign substances (called allergens) come into contact with your eyes’ mast cells. These cells respond by releasing a number of chemicals, including histamine, causing an allergic reaction.

A number of different allergens can trigger an allergic reaction in your eyes, including:

There are many different types of eye allergies. Each type has its own symptoms.

Seasonal allergic conjunctivitis

Seasonal allergic conjunctivitis (SAC) is the most common type of eye allergy. People tend to experience symptoms in the spring, summer, or fall, depending on the kind of pollen that’s in the air.

Symptoms of SAC include:

  • itchiness
  • stinging/burning
  • redness
  • watery discharge

Perennial allergic conjunctivitis

The symptoms of perennial allergic conjunctivitis (PAC) are the same as SAC, but they occur year-round and tend to be more mild. The other main difference is that PAC reactions are typically triggered by household allergens, like dust and mold, as opposed to pollen.

Vernal keratoconjunctivitis

Vernal keratoconjunctivitis is a serious eye allergy that can occur year-round. If left untreated, it can severely impair your vision.

Symptoms tend to get much worse during prominent allergy seasons, and the allergy is mainly seen in young males. Vernal keratoconjunctivitis is also usually accompanied by eczema or asthma, as well as:

  • severe itchiness
  • thick mucus and high tear production
  • foreign body sensation (feeling like you have something in your eye)
  • light sensitivity

Atopic keratoconjunctivitis

Atopic keratoconjunctivitis is similar to vernal keratoconjunctivitis, except it’s commonly seen in older patients. If left untreated, it can result in scarring on your cornea.

Contact allergic conjunctivitis

Contact allergic conjunctivitis is the result of contact lens irritation. Symptoms include:

  • itchiness
  • redness
  • mucus in eye discharge
  • discomfort wearing contact lenses

Giant papillary conjunctivitis

Giant papillary conjunctivitis is a severe form of contact allergic conjunctivitis in which sacs of fluid form in the upper inner eyelid.

Symptoms in addition to those of contact allergic conjunctivitis include:

  • puffiness
  • tearing
  • blurred vision
  • foreign body sensation

Treatment options vary based on the severity of your reaction, as well as the type of reaction. Allergy medications for your eyes come in the form of prescription or over-the-counter (OTC) eye drops, as well as pills or liquids.

Antihistamine treatments

Antihistamine treatments are medications that help block histamine, the chemical that’s usually responsible for an allergic reaction. Your doctor might recommend oral antihistamines such as:

  • cetirizine (Zyrtec)
  • loratadine (Claritin)
  • fexofenadine (Allegra)
  • levocetirizine (Xyzal)
  • diphenhydramine or chlorpheniramine (commonly cause drowsiness)

Your doctor might also recommend eye drops such as:

If your eye drops sting or burn, consider using refrigerated artificial-tear drops before the medicated ones.

Corticosteroids

  • Corticosteroid eye drops — such as prednisone (Omnipred) — provide relief by suppressing inflammation
  • loteprednol (Alrex)
  • fluorometholone (Flarex)

Mast cell stabilizers

Mast cell stabilizer treatments are prescription eye drops typically used when antihistamines are not effective. These medications stop the reaction-inducing chemicals releasing from your immune system. They include:

  • cromolyn (Crolom)
  • lodoxamide (Alomide)
  • nedocromil (Alocril)

It’s important to note that some people are allergic to the preservative chemicals in eye drops. In this case, your doctor or pharmacist will suggest drops that are preservative-free.

Other treatment options for general allergy relief include nasal sprays, inhalers, and skin creams.

Depending on the type of allergy you have, there are a number of steps you can take to prevent your allergies from flaring up.

  • Pollen allergies. Avoid going outdoors on days with high pollen counts. Use air conditioning (if you have it) and keep your windows closed to keep your house pollen-free.
  • Mold allergies. High humidity causes mold to grow, so keep the humidity level in your house around 30 to 50 percent. Dehumidifiers are helpful in controlling home humidity.
  • Dust allergies. Protect yourself from dust mites, especially in your bedroom. For your bed, use sheets and pillow covers that are classified as allergen-reducing. Wash your sheets and pillows often using hot water.
  • Pet allergies. Keep animals outside of your home as much as possible. Make sure to wash your hands and clothes vigorously after coming into contact with any animals.

For general prevention, clean your floors using a damp mop or rag, instead of a broom, to better trap allergens. Also avoid rubbing your eyes, as this will only irritate them further.

While there are several ways to prevent allergies from flaring, there are also ways to improve your sensitivity to allergies through allergen immunotherapy.

Allergen immunotherapy is a gradual increase in exposure to different allergens. It’s especially useful for environmental allergies, like pollen, mold and dust.

The purpose is to train your immune system to not react when allergens are present. It’s often used when other treatments have not worked. Types of allergen immunotherapy include allergy shots and sublingual immunotherapy.

Allergy shots

Allergy shots are typically injections of an allergen once or twice a week for three to six months. After the first six months, a series of maintenance shots will continue to be given for up to five years, though these are administered much less frequently. Some side effects include irritation around the area of injection, along with regular allergy symptoms like sneezing or hives.

Sublingual immunotherapy

Sublingual immunotherapy (SLIT) involves placing a tablet under your tongue and allowing it to be absorbed. These tablets contain pollens from all different types of grass, including short ragweed, orchard, perennial rye, sweet vernal, timothy and Kentucky blue.

Particularly for pollen allergies, this method has shown to reduce congestion, eye irritation, and other hay fever symptoms when conducted daily. Additionally, SLIT may prevent the development of asthma and might improve asthma-related symptoms.

If your itchy eye allergy symptoms are not getting any better, or OTC remedies aren’t providing any relief, consider seeing an allergist. They can review your medical history, conduct tests to reveal any underlying allergies, and suggest appropriate treatment options.