Eye allergies, also known as allergic conjunctivitis, are a widespread condition. They occur when the eyes react to normally harmless substances, called allergens. The immune system mistakenly identifies these as threats, initiating a defensive response. Unlike infections, eye allergies are not contagious.
Common Sensations
Intense itching is a primary sensation of eye allergies, often described as the hallmark symptom. This itchiness can be persistent, leading to an urge to rub the eyes, which may worsen irritation. Many also report a burning or stinging sensation. A gritty or foreign body sensation, like sand in the eye, is common. These feelings contribute to general discomfort.
Accompanying Signs and Discomforts
Beyond internal sensations, eye allergies manifest with visible signs. Redness, often in the white part of the eye or inner eyelid due to swollen blood vessels, is noticeable. Excessive tearing or watery eyes are common, as is swelling of the eyelids or the conjunctiva, the clear membrane covering the eye, which can make eyes appear puffy. Sensitivity to light, or photophobia, also adds discomfort. Chronic dark circles under the eyes, known as “allergic shiners,” may also occur.
Understanding the Cause of Symptoms
These sensations and signs stem from the body’s immune response to allergens like pollen, dust mites, or pet dander. When allergens contact the eye, mast cells in the conjunctiva release histamine. Histamine causes inflammation, dilating blood vessels and leading to redness and swelling. It also stimulates nerve endings, causing itching and burning sensations.
Distinguishing Eye Allergies From Other Conditions
Eye allergies have distinct characteristics that differentiate them from other eye conditions like dry eye or viral conjunctivitis. Prominent itching is the most significant distinguishing factor for eye allergies, which is typically much more intense than any itchiness experienced with dry eyes. Dry eye often presents with a persistent gritty or scratchy feeling, burning, and dryness, with less pronounced itching. Symptoms may worsen with activities like reading or screen use. Unlike allergies, dry eye results from insufficient or poor-quality tears.
Viral conjunctivitis, or pink eye, also differs. Allergic conjunctivitis usually affects both eyes simultaneously and rarely involves a thick, pus-like discharge. Viral conjunctivitis, often contagious, can start in one eye before spreading, and may produce a watery discharge, sometimes accompanied by cold or flu symptoms. While both can cause redness and watery eyes, allergies feature intense itching, whereas viral pink eye often includes more general irritation and soreness. If eye symptoms are severe, persistent, or include pain or vision changes, seek advice from a healthcare provider.