How Do Allergies Affect the Eyes?

Your eyes are one of the most sensitive parts of the body, so they are vulnerable to anything  that may cause pain. Just like the rest of the body, your eyes are susceptible to allergic reactions. You will agree that few things are more irritating than red, itchy, watery, burning and puffy eyes. 

The most common fixes to the condition is a cold compress and over-the-counter medication, which is how many people deal with it.

But before you can begin to understand which long-term solution is best for your allergies, you first need to understand how they affect your eyes. Here is how.

What Are Allergies?

Allergies are hypersensitive immune reactions to a harmless foreign material (food, plant pollen, medicine, etc.) in the body. These foreign substances are called allergens.

When allergens enter your immune system, they cause your body to react as if it is countering a real threat, activating an immunological response. Reactions can occur in any part of the body part, including your eyes.

When confronted with an allergen, eyes produce histamine, found in the body cells, to start a fighting-off process. It is this neurotransmitter production that your conjunctiva and eyelids to grow itchy by even routine allergens such as pollen.

Eye allergies are common, and people who have them are usually also vulnerable to nasal allergies. For some people, allergies are seasonal. But other people experience eye allergies regularly, especially after exposure to perfume, smoke, pet dander and dust in a residential setting or a commercial office.

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Symptoms of Eye Allergies

Many people who complain about eye allergies experience itchiness as an immediate discomfort. However, others do not have itchiness but feel some eye fatigue and a burning sensation that causes them to rub their eyes. Other common allergy symptoms in the eyes include:

• Tearing
• Lid swelling
• Redness
• Swollen eye
• Grittiness
• Itchiness
• Burning sensation
• Watery eyes

Symptoms vary from person to person and depend on the complexity of the body’s reactions to the specific allergen. Expansion of blood vessels allows for a greater flow of allergic and inflammatory molecules from the bloodstream into the eye, where the reaction occurs.  

If nasal allergies accompany these eye-related symptoms, you are likely to have a stuffy nose, a runny nose and a penchant for sneezing. Other likely reactions are coughing, a headache and a sore or itchy throat.

If you experience a stinging in the eyes, acute dryness or the feeling of a foreign object in your eyes, these could symptoms of dry-eye syndrome.

Accompanying Symptoms

Allergic symptoms usually occur when you are in close contact or proximity with an allergen. This could happen if you are playing with your pets, mowing your lawn or spending a lot of time outdoors during a heavy pollen time of year.

Beyond the discomfort and annoyance, some eye allergies can disable you, causing a severe enough reaction that you cannot see or cause you to not want to keep your eyes closed. If that is the case, you are likely having symptoms like:

• Scaling around the eyes
• Clear, watery discharge
• Eye fatigue

These accompanying symptoms affect your activity level and your desire to participate in daily hobbies. Beyond activities, people also get concerned about their appearance as puffy eyelids and red eyes give the impression of illness and body weakness.

Short term, allergic reactions last until you (or a doctor) find the right way to medicate them with either over-the-counter allergy medication or prescription drugs. You may have to sample more than one medication to find the one that works best for you.

Long-term allergic reactions usually last between four and eight weeks. In worst-case scenarios, allergies may bring further eye complications that could last for more than three months.

Ophthalmologists also report that most eye allergies reduce or stop when you are away from allergens, while other eye allergies will last through a pollen season.

Eye Allergy Complications

Eye allergies are commonplace. Though temporary, the chronic nature of this untreated disease may have complications that affect the entire body. The most common eye allergy complications are:

• Limbal stem cell deficiency
• Secondary keratoconus

Limbal Stem Cell Deficiency

The main characteristic of LSCD is the deficiency or loss of stem cells in your limbus. These cells are critical for the functioning of the limbus and re-population of corneal epithelium. With such a complication, the corneal epithelium fails to renew and repair itself when the stem cells are lost.

Ophthalmologists also say that the damaged limbus stem cells stop the renewal process, causing partial or complete loss of stem cells. This may cause the opaque conjunctiva to start growing over your cornea and lead to excruciating chronic pain in the eyes.

At this point, you will start experiencing too much pain in the eye, uncomfortable irritation, excessive light sensitivity, blurred vision, contact lens intolerance, and in the worst-case scenarios, loss of clear vision.

Secondary Keratoconus

Secondary keratoconus is progressive, non-inflammatory corneal disorder. It occurs when the cornea thins then gradually bulges outwards to form a visible cone shape.

In the primary stages, you could be struggling with keratoconus but still can correct your vision problems with soft contact lenses or glasses.

If the condition progresses to the secondary stage, you’ll require a cornea transplant to maintain or restore your vision. The eye complication results in visible symptoms such as thinning, ectasia or increased curvature. You may need rigid, gas permeable contact lenses in the secondary stage.

Secondary keratoconus can affect both eyes or only one eye and is common among young people between ages 10 to 25. However, the complication progresses gradually even when the patient grows old if not treated.

One eye will be more diseased than the other when it affects both eyes.

FAQs

What are the symptoms of allergies in the eyes?

The most common symptoms include a watery cornea, itchiness, redness, soreness and swollen eyelids. Others may experience sticky eyes or blurred vision, depending on the complexity of the allergy.  

Do allergies make your vision blurry?

Chronic allergies may blur your vision, making it cloudy and unclear. They damage the retina’s blood vessels, which is a sensitive part in the eye that senses light.

Can seasonal allergies affect the eyes?

Seasonal allergic reactions are the most common ocular allergies. Their effects are temporary, and soon subside when your exposure to allergens lessens. These allergies do not have significant health impacts, and you may only feel itchiness or tearing. Otherwise, the allergies do not cause any further complications.

References

1. Allergy and Hypersensitivity. (2001) Immunobiology: The Immune System in Health and Disease. 

2. Eye Allergies (Allergic Conjunctivitis). (October 2015). Asthma and Allergy Foundation of America.

3. Limbal Stem Cell Deficiency—Demography and Underlying Causes. (February 2018). American Journal of Ophthalmology. 

4. Pathogenesis and complications of chronic eye rubbing in ocular allergy. (October 2019). Current Opinion in Allergy and Clinical Immunology.