Eye Allergies Overview
Up to 50 million Americans suffer from the miseries of allergies, with allergic reactions involving the eyes being a common complaint. An allergic reaction that affects the conjunctiva, a clear layer of skin overlying the eyes, is commonly referred to as allergic conjunctivitis.

Allergic conjunctivitis is divided into several major subtypes, but the most common subtypes are seasonal allergic conjunctivitis (SAC) and perennial allergic conjunctivitis (PAC). SAC and PAC are triggered by an immune reaction involving a sensitized individual and an allergen. Simply stated, this means that if you are allergic to a particular substance and then come into contact with it, you experience an allergic reaction (eg, itching, sneezing).
Although it frequently occurs, allergic conjunctivitis is most commonly seen in areas with high seasonal allergens.
Causes
Ocular (eye) allergies often affect the conjunctiva, a clear layer of skin overlying the eyes. This clear layer of skin is the same type of skin that lines the inside surface of the nose. Because these two areas are so similar, the same allergens (substances that induce an allergic reaction) can trigger the same allergic response in both areas.
Common allergens include:
Pollen
Grass
Weeds
Dust
- Pet dander
The main difference between SAC and PAC is the timing of the symptoms.
If you have SAC, you generally have problems for a short period of time.
You may be bothered in the spring by tree pollen, in the summer by grass pollen, or in the fall by weed pollen.
Generally, your symptoms resolve during other times of the year, especially in the winter.
If you have PAC, your problems probably last throughout the year.
Instead of outdoor allergens, you have problems with indoor allergens, such as dust mites, cockroaches, and pet dander.
Seasonal outdoor allergens may worsen your problems if you are sensitive to them as well.
Symptoms
SAC and PAC have identical symptoms, only the timing of the symptoms is different.
With SAC, your symptoms are generally limited to a particular season (ie, spring, summer, fall).
With PAC, your symptoms probably last all year.
Almost always, the symptom of itching indicates an allergic reaction. This is true of allergic conjunctivitis, where the primary symptom is ocular itching. In addition to ocular itching, you may experience the following symptoms:
When to Seek Medical Care
If you suffer from allergies but can identify and avoid whatever you are allergic to, your allergies should improve markedly. If you are unable to identify or avoid the allergens, seeking care for your ocular allergies from an ophthalmologist may help to make them more bearable.
If you have SAC, you may want to make an appointment with your ophthalmologist prior to the season in which you suffer from allergies in order to start treatment before your symptoms from ocular allergies begin.
If you have PAC, routine appointments with your ophthalmologist may be helpful to monitor your ocular allergies. Occasional flare-ups of your symptoms may require more frequent visits. Consultation with an allergist may be very beneficial.
Questions to Ask the Doctor
Exams and Tests
Frequently, your ophthalmologist is able to diagnose ocular allergies from your complaints alone. As part of the eye examination, your eyes are examined to help rule out other problems.
The front of your eyes are examined using a special microscope, called a slit lamp. Using the slit lamp, your ophthalmologist checks your eyes for dilated blood vessels, conjunctival swelling, and eyelid swelling, all of which are indicative of an allergic reaction.
Rarely, scraping of the conjunctiva is performed to check for eosinophils. Eosinophils are certain cells that are commonly associated with allergies; however, they are only found in the most severe cases.
Self-Care at Home
With allergies, "an ounce of prevention is worth a pound of cure." Avoidance of the allergen(s) is the mainstay in the treatment of allergies. If you can identify and avoid the particular agent that you are allergic to, your symptoms will improve dramatically.
To further help alleviate your symptoms, you may want to try these tips for self-care at home.
Reduce the allergen load by minimizing clutter where allergens can collect.
Limit pillows, bedding, draperies, and other linens, such as dust ruffles and canopies.
Reduce the number of knickknacks that collect dust.
Minimize carpeting that can harbor dust mites.
Clean regularly and thoroughly to remove dust and mold.
Eliminate water leaks and standing water that encourage mold growth.
Use barriers and filters.
Cover mattresses and pillows with allergen impermeable covers.
Use allergen filters in both the furnace and the air conditioner in your home. Also, be sure to change them regularly.
Keep outdoor allergens outdoors by keeping windows and doors closed.
Avoid pet dander and other irritants.
Unfortunately, avoidance of the allergen(s) is not always easy or possible. In this case, the following at-home treatments may provide you with some relief from your ocular allergies.
Apply cold compresses to your eyes to help reduce the allergic reaction.
Use artificial tears/lubricating eyedrops as needed to help flush out allergens that get into your eyes.
Use over-the-counter medications, such as allergy eyedrops and oral antihistamines, as directed for mild allergies.