A yellow spot on the white part of the eye, known as the conjunctiva, often represents a change in the tissue of the eye’s outer layer. While the presence of a spot or growth may seem alarming, it is frequently a sign of a non-cancerous condition caused by environmental factors. This article clarifies the most frequent causes of this symptom, distinguishing between common, harmless growths and those requiring professional attention.
Pinguecula: The Common Non-Cancerous Deposit
A pinguecula is the most frequent cause of a yellow spot on the eye, presenting as a slightly raised, yellowish or white mass on the conjunctiva. This benign growth typically appears on the side of the eye closer to the nose, though it can also occur on the temporal side. The spot is an accumulation of protein, fat, or calcium deposits within the conjunctival tissue.
The primary cause is chronic exposure to environmental irritants, especially ultraviolet (UV) radiation from the sun. Years of sun exposure can lead to a breakdown of the collagen fibers in the conjunctiva. Exposure to wind, dust, and dry conditions also contributes to the irritation and development of these growths.
Pingueculae are generally asymptomatic. However, the raised bump can interfere with the natural spread of the tear film, sometimes leading to dry eye symptoms. This disruption can cause mild irritation, a gritty sensation, or occasional redness and inflammation, a condition known as pingueculitis.
While a pinguecula may slowly increase in size, it remains confined to the conjunctiva and does not grow onto the clear dome of the eye, the cornea. It is essentially a sign of aging and environmental wear on the ocular surface. Since it does not threaten vision, treatment is usually unnecessary unless symptoms become persistent or severe.
Pterygium: The Potential for Growth
A pterygium, often referred to as “surfer’s eye,” is a different form of growth that starts on the conjunctiva and is concerning due to its progressive nature. Unlike a pinguecula, a pterygium is a fleshy, wedge-shaped growth of conjunctival tissue that contains blood vessels. It commonly begins near the corner of the eye closest to the nose.
The defining difference is the pterygium’s ability to invade and grow over the cornea. This growth is an abnormal process triggered by chronic inflammation and damage, overwhelmingly linked to prolonged UV light exposure. The tissue thickens and extends beyond its normal boundaries, gradually spreading toward the center of the visual axis.
The progressive growth carries several risks to vision. As the tissue advances over the cornea, it can physically block light, directly impairing central vision. More commonly, the tissue pulls on the corneal surface, changing its shape and inducing an irregular curvature known as astigmatism.
This change in refractive power can cause blurry vision even before the growth reaches the direct line of sight. Monitoring by an eye care professional is always necessary, even if it is small and currently asymptomatic.
When to Seek Professional Diagnosis
While many yellow spots are benign growths, professional examination is necessary to confirm the diagnosis and rule out rarer conditions. An eye care provider uses a specialized tool called a slit-lamp biomicroscope to examine the growth in detail and determine its exact nature and size. A confirmed diagnosis is the only way to differentiate between the harmless pinguecula and the potentially vision-threatening pterygium.
Prompt medical evaluation is needed if there is any rapid change in the size, shape, or color of the yellow spot. Severe or persistent pain, sudden changes in vision, or a feeling that the eye cannot close properly are also urgent symptoms.
Consultation is warranted if the yellow spot is accompanied by severe redness that does not improve with over-the-counter drops, or if the growth appears to be actively expanding onto the clear cornea. Yellow discoloration can rarely signal systemic issues like jaundice or ocular surface tumors. A thorough eye exam is the only way to exclude these possibilities and establish an appropriate long-term care plan.
Management and Long-Term Eye Care
Management strategies for both pinguecula and pterygium focus on controlling symptoms and preventing further growth. For mild cases, the primary treatment involves the use of lubricating eye drops to keep the ocular surface moist and reduce irritation. These artificial tears help alleviate the gritty sensation or dryness that the raised growth can cause.
If the growth becomes inflamed and red, a condition often referred to as a flare-up, an eye doctor may prescribe short-term anti-inflammatory drops. These often contain a low-dose steroid to reduce swelling and discomfort.
The most effective long-term measure for preventing progression is strict protection from UV light. Wearing high-quality sunglasses that block 100% of UVA and UVB rays is highly recommended, especially when spending time outdoors. Wide-brimmed hats provide additional shade and protection from wind and dust, which are known irritants.
Surgical excision is typically reserved for pterygium when it threatens vision by either growing over the pupil or causing significant astigmatism. It may also be considered if a pinguecula causes chronic discomfort that fails to respond to medical treatment.