Seeing a sudden, raised bump or “bubble” on the white part of the eye can be alarming. This symptom, which can appear clear, yellowish, or bright red, is typically confined to the conjunctiva, the thin, transparent membrane covering the sclera, or white of the eye. While the eye is a delicate structure, many of these bubble-like appearances have common and relatively harmless explanations rooted in tissue changes, fluid accumulation, or minor bleeding. Understanding the different forms these growths take can help clarify when the symptom is benign and when it warrants professional medical attention.
Common Tissue Growths (Pinguecula and Pterygium)
A common cause of a bump on the eye involves chronic changes to the tissue itself, resulting in growths known as pinguecula and pterygium. These conditions develop due to prolonged exposure to environmental factors like ultraviolet (UV) radiation from the sun, wind, and dust. They represent a slow, adaptive response by the conjunctival tissue to these external irritants over time.
A pinguecula presents as a yellowish, raised deposit on the conjunctiva, generally located close to the edge of the cornea, often on the side nearer to the nose. This growth is composed of deposits of protein, fat, or calcium accumulated over many years. A pinguecula is considered benign and remains confined to the conjunctiva, meaning it does not extend onto the cornea and typically avoids impacting vision.
A pterygium, sometimes referred to as “surfer’s eye,” often begins similarly to a pinguecula, but is a fleshy, wedge-shaped growth. This tissue mass is highly vascularized and can slowly grow across the cornea, which is the clear, dome-shaped front surface of the eye. As a pterygium advances, it can physically block or distort the cornea, potentially leading to decreased or blurred vision.
Both conditions are associated with dry eyes and can cause symptoms like redness, irritation, or the sensation of having a foreign body present. Protection from further environmental exposure is a standard preventative measure, including wearing wraparound sunglasses that block UV light and using artificial tears. While a pinguecula rarely requires removal, a pterygium may be surgically excised if it threatens to impair sight.
Acute Fluid Accumulation (Chemosis and Cysts)
Some bubbles in the eye result from a rapid, acute accumulation of clear fluid, a condition often referred to as chemosis. Chemosis involves the swelling of the conjunctiva due to inflammation, causing the tissue to visibly bulge and sometimes appear like a large, clear blister. This swelling occurs when the tiny blood vessels in the conjunctiva become permeable, allowing fluid to leak into the surrounding tissue.
The most frequent triggers for chemosis include allergic reactions, such as exposure to pollen or pet dander, which prompt the body to release histamines. Infections, specifically viral or bacterial conjunctivitis (pink eye), also cause inflammation that leads to this pronounced swelling. Physical irritation, like excessive eye rubbing, or trauma from a foreign body or chemical splash, can similarly induce the rapid fluid buildup. In many cases, chemosis resolves spontaneously once the underlying cause, such as the allergen or infection, is addressed or removed.
Less commonly, a bubble on the eye may represent a conjunctival cyst, which is a small, localized pocket of fluid or mucus trapped beneath the surface of the conjunctiva. These cysts can form slowly or suddenly, often resulting from a blockage of a tiny gland on the eye’s surface. Unlike the broader swelling of chemosis, these cysts are discrete, dome-shaped structures that are usually translucent. While many small cysts disappear on their own, larger or persistent ones may require minor intervention, such as drainage by an eye care professional.
Blood Beneath the Surface (Subconjunctival Hemorrhage)
A different type of alarming “bubble” appearance is the subconjunctival hemorrhage, characterized by a bright red patch on the white of the eye. This condition occurs when one of the delicate, small blood vessels located just beneath the conjunctiva ruptures. Because the blood is trapped between the conjunctiva and the underlying sclera, it pools and creates a sharply defined red mark.
Despite the dramatic appearance, a subconjunctival hemorrhage is typically painless and benign, generally not affecting vision. The rupture often happens following a sudden, temporary increase in blood pressure within the head or chest. Common causes include vigorous sneezing, coughing fits, straining during heavy lifting, or vomiting. Minor trauma to the eye can also be a trigger, though sometimes the cause remains unknown.
The extravasated blood will reabsorb naturally over time, similar to a bruise on the skin. Resolution usually takes between one and two weeks, with the bright red color fading and sometimes turning yellowish as the blood is metabolized. No specific treatment is usually required, although artificial tears can be used if the eye feels scratchy or irritated during the healing process.
Warning Signs and When to See a Doctor
While many bubble-like symptoms are harmless, certain signs indicate the problem is more serious and requires prompt medical attention.
- Any sudden change in vision, including blurriness, distortion, or partial loss of sight, should be evaluated immediately.
- Severe or increasing pain in the eye, rather than just a feeling of irritation or grittiness, necessitates an urgent consultation.
- If the bubble or growth is accompanied by light sensitivity (photophobia) or a continuous discharge from the eye, it could signal an infection or severe inflammation.
- A bubble that begins to grow rapidly or change color quickly also warrants a professional examination.
- If the symptom appears after a significant injury to the eye, such as a direct hit or a chemical splash, seeking immediate medical care is mandatory.
Vision changes suggest that the underlying issue may be affecting the cornea or deeper structures of the eye. An eye care professional can accurately diagnose the cause of the bubble and determine if intervention is necessary.