What is Eye Allergy?

The eye is an essential organ which acts in the same way as a camera does. It is an integral sense organ which detects images; however it is equally sensitive. In the eye, the image is created on the retina.

The cornea¹ is a thin transparent film found on the surface of the eye. The lacrimal glands are situated on the upper and lower portions of the eye; they are responsible for the production of tears. Allergies and eyes are often linked.

Eye allergies are mainly related to the conjunctiva. It is a tissue lining that covers the eyeball,it is rich in blood vessels. The conjunctiva is a thin membrane which keeps the front surface of the eye as well as the eyelids lubricated. It also protects the eye from harmful particles and pathogens.

Eye allergies are also termed as allergic conjunctivitis. Allergic conjunctivitis occurs when the eye comes in contact with an allergen. An allergen is defined as a substance which can irritate the eye. In order to counter the allergen, the eye produces a certain chemical called histamine. As a result, the eyelids and conjunctiva become watery, swollen and red. It also results in a burning sensation in the eye and the person may feel like constantly itching their eyes.

Causes of Eye Allergies

• Allergic Asthma

Allergic asthma causes the immune system to become extra sensitive. Therefore, it starts reacting to harmless allergens in response. The airways overreact and become stretched. Histamine is produced excessively, and airways fill up with mucus.

• Dermatitis

It is a form of eczema or psoriasis. The skin around the eyes and eyelids becomes dry and flakey. This causes it to fall off. It ends up entering the eye as an allergen.

• Irritants

These include a number of substances such as pollutants and some chemicals. They are found inside as well as outside. One of the most prominent examples is pollen from grass,trees, and plants such as ragweed. Other examples include mold, dust, pet dander and smoke particles in the air. Irritation may become worse due to certain activities such as cleaning or grooming a pet. Reactions may also take place due to preservatives in eye drops, perfumes,  cosmetics or even drugs.

Types of Eye Allergies

Eye allergies are divided into five types:

• Seasonal allergic conjunctivitis

It is the most common type of ocular allergy. It is related to pollens that release spores during specific seasons by flowers, grasses, and plants. The conjunctiva becomes inflamed and swollen. Most cases of SAC (Seasonal allergic conjunctivitis) occur during spring and autumn. Seasonal allergic conjunctivitis may affect adults and children both.

• Perennial allergic conjunctivitis

Perennial allergic conjunctivitis occurs all around the season. It is triggered by irritants and is not contagious like most eye infections. The most common perennial allergens include fur, feathers, animal skin, dust mites,tobacco smoke, etc. In most cases, the signs and symptoms disappear after a few days.However, they may return if the person is exposed to the same environmental conditions. Individuals of all ages are at risk.

• Vernal keratoconjunctivitis

 Vernal keratoconjunctivitis is a particular type of allergic conjunctivitis which affects both the eyes and is strongly related to family history. It is especially common among younger boys. Patients with this type of conjunctivitis also have a family background of asthma, rhinitis, and eczema.

• Atopic keratoconjunctivitis

It is a chronic inflammatory ocular condition. It is genetic and happens due to atopic dermatitis. Atopic dermatitis is a condition that makes your skin itchy and red. Hence, it is bound to affect the eyes. Atopic keratoconjunctivitis is similar to vernal keratoconjunctivitis and can go all year around.

• Contact allergic conjunctivitis

In this case, the eye is irritated by contact lenses. The proteins from the tears bind to the surface of the lens. This causes severe discomfort from itching and constant rubbing. Hence, the eyes can ultimately become puffy and swollen.

Signs & Symptoms of Eye Allergies

Itching is one of the most dominant symptoms.The eyes become extremely watery and start releasing a  mucus discharge. The person may feel a painful or burning sensation in their eyes which is further intensified by constant itching.

Photophobia is defined as the intolerance of light. All types of light including artificial and natural may cause discomfort to the eyes. This results in irritation of the eyes and eventually,they tear up.

The eyes become puffy due to swollen eyelids. This happens when a person rubs their eyes a lot. The whole area starts to feel sore and tender.

Treatment

• Medications
• Eye drops

Eye drops are responsible for diluting the allergen. This prevents the eye from getting irritated. There are two types of these :

1. Artificial tears
2. Those that prevent rednes

• Decongestants

Decongestants² decrease the redness of the eyes by constricting the blood vessels. However, they are not recommended for long-term usage.

• Oral antihistamines

They block the effect of histamines. Oral antihistamines bring relief from symptoms that occur due to conjunctivitis. Oral dose also contributes to helping to get rid of runny noses. They are available readily at pharmacies.

• Immunotherapy shots

Immunotherapy shots are also referred to as allergy shots. They should be received at regular intervals over a time period of three to five years. These type of shots can be used to control symptoms by insect stings, indoor allergens, and seasonal allergic conjunctivitis.

• Mast cell stabilizers

It is a specific type of medicine that plays a major role in controlling symptoms of allergic conjunctivitis over a longer period of time. Hence, their effects last longer as compared to antihistamines. Antihistamines and mast cell stabilizers can be taken together. The antihistamines provide relief until the mast cell stabilizers start functioning properly.

• Homecare

There are a number of home remedies and strategies which can play a significant role in preventing eye allergies. It is always better to keep windows closed when the pollen count is high. Avoidance of harsh chemicals, perfumes, and scented air fresheners could be a suitable option. An air purifier removes toxins from the air making it free of allergens. It is recommended to wash clothes and pillowcases frequently.

Examples of indoor plants that are cheap and act as air purifiers are spider plant and dracaenas. Also, when indoors try using a vacuum cleaner with a high energy particle absorber (HEPA) filter. In order to stop molds from growing, installing a dehumidifier would be a good option.

• Outdoor care

Avoid mowing lawns during the pollen season as it can prevent eye allergies. When driving, one should ensure windows are closed, and the face is covered. Sunglasses can also be worn; this will decrease the probability of allergens coming into contact with the eyes. Before stepping outside, remember to use saline drops.

References:

1. Massachusetts Eye And Ear – Function of the Cornea 
2. WebMD – Decongestants & Antihistamines for the Common Cold  IMPORTANT NOTE: The above information is intended to increase awareness of health information and does not suggest treatment or diagnosis. This information is not a substitute for individual medical attention and should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. See your health care professional for medical advice and treatment.