Yellowing in the white part of the eye, known as the sclera, indicates an underlying change in the body. When this discoloration is localized to the corners or edges, it often points toward common, non-systemic growths. If the yellowing is uniform and covers the entire sclera, it suggests a more serious, systemic issue related to internal processes, often involving the chemical bilirubin. Understanding this distinction is important because the cause can range from a minor cosmetic issue to a condition requiring immediate medical attention.
Benign Localized Growths
Yellowing confined to a distinct area, particularly near the inner or outer corner of the eye, is frequently caused by non-cancerous changes to the conjunctiva. The conjunctiva is the thin, transparent membrane covering the white part of the eye. These localized spots typically result from long-term exposure to harsh environmental elements.
One common growth is a pinguecula, which appears as a yellowish, slightly raised patch or bump on the conjunctiva, usually closer to the nose. This growth is composed of accumulated deposits of fat, protein, and calcium, often due to sun exposure, wind, and dust irritation. Pingueculae are generally slow-growing and do not extend onto the cornea.
Another possibility is a pterygium, sometimes called “surfer’s eye” due to its association with prolonged sun exposure. A pterygium is a fleshy, wedge-shaped growth that also begins on the conjunctiva, often near the inner corner. It contains visible blood vessels, giving it a pinkish-yellow hue.
The defining difference from a pinguecula is that a pterygium can grow across the cornea, potentially distorting its shape and affecting vision.
Both conditions arise because the exposed tissue of the conjunctiva is vulnerable to ultraviolet (UV) radiation damage. This damage causes the tissue’s elastic fibers to degenerate and clump together, resulting in localized yellowing and thickening. While these growths are typically monitored, they may cause irritation, dryness, or the feeling of something being in the eye. These symptoms can be managed with artificial tears or anti-inflammatory drops.
Bilirubin and Systemic Health Issues
When the entire sclera develops a yellow tint, this condition is known as scleral icterus, a symptom of systemic jaundice. Jaundice is caused by an excessive buildup of bilirubin, a yellow-orange pigment, in the bloodstream. Bilirubin is a natural byproduct formed when old red blood cells are broken down in the body.
Normally, the liver processes this unconjugated bilirubin, converting it into a water-soluble form called conjugated bilirubin, which is then excreted in the bile. Jaundice occurs when there is a disruption at any point in this process, leading to high levels of the pigment depositing in the body’s tissues. The yellowing of the eyes is often the earliest and most noticeable sign of this elevated level.
Systemic issues that cause jaundice are broadly categorized based on where the disruption occurs. Pre-hepatic causes involve conditions that lead to excessive red blood cell breakdown, such as hemolytic anemia, which overwhelms the liver’s capacity to process bilirubin. Hepatic causes include liver diseases like hepatitis, cirrhosis, or alcohol-related liver damage, where the liver cells themselves are unable to properly process the pigment. Post-hepatic, or obstructive, causes occur when there is a blockage in the bile ducts that transport conjugated bilirubin out of the liver, such as from gallstones or tumors.
The key distinction here is the appearance: unlike the specific bumps of localized growths, jaundice presents as a diffuse yellowing that covers the entire white of the eye. This widespread discoloration is a medical concern because it indicates a problem with liver function, blood cell metabolism, or bile flow.
Knowing When to Seek Medical Care
While a small, stable yellow bump may be a benign pinguecula, any change in eye color warrants professional evaluation. Seek medical care if the yellowing is new, rapidly worsening, or accompanied by other systemic symptoms. An eye care professional or physician can accurately determine the underlying cause by examining the eye and considering the overall health picture.
Immediate medical attention is recommended if the yellowing is widespread across the entire sclera or if you experience accompanying signs of systemic issues. These serious indicators include:
- Unexplained fatigue
- Dark-colored urine
- Pale or clay-colored stools
- Persistent abdominal pain
- Fever
- A sudden change in vision
These symptoms suggest a possible issue with the liver or bile ducts that requires prompt diagnosis and treatment.
A healthcare provider will perform a visual inspection and may order blood tests to measure bilirubin levels and liver enzymes. Treatment depends entirely on the diagnosis. A benign growth may only require monitoring and lubricating eye drops. Systemic jaundice necessitates addressing the underlying medical condition, such as managing liver disease or surgically removing a bile duct obstruction.