A pterygium is a benign growth on the eye’s surface that most people notice as a fleshy pink-white triangle creeping in from the corner. Small ones rarely cause trouble. Once they start affecting your cornea, that changes.
A pterygium (the plural is pterygia) is an abnormal growth of conjunctival tissue that spreads from the white of the eye onto the clear cornea. It almost always starts at the nasal side, moving toward the centre of the eye. The condition is benign – it is not a tumour, it will not spread to other parts of the body – but it can cause persistent redness, irritation, and over time, significant distortion of the cornea that affects vision. UV light is the main driver. People who spend a lot of time outdoors, particularly in sunny, dusty, or windy environments, are far more likely to develop one than people who don’t.
What You Need to Know About Pterygium
- A pterygium grows from the conjunctiva onto the cornea and can affect vision if it reaches the visual axis or causes significant astigmatism
- UV exposure is the primary cause – it is sometimes called “surfer’s eye” for good reason
- Small pterygia that don’t threaten vision are managed conservatively with lubricating drops and UV protection
- Surgery is indicated when vision is affected, astigmatism worsens, the growth approaches the pupil, or symptoms are intolerable
- Recurrence after surgery is common – rates are much lower with conjunctival autograft than with older bare-sclera excision techniques
- A related but distinct lesion, the pinguecula, is a similar yellowish deposit that does not grow onto the cornea
What Causes a Pterygium?
UV radiation is central. Chronic exposure to ultraviolet light, particularly UV-B, causes changes in the limbal stem cells – the stem cells that sit at the junction between the cornea and conjunctiva. Over years, this leads to abnormal conjunctival proliferation that extends across the corneal surface. The pattern of distribution globally matches UV exposure almost exactly: the condition is far more prevalent in populations living within 40 degrees of the equator.
Dry, dusty, and windy environments compound the risk. Outdoor workers – farmers, fishermen, construction workers – and people who spend significant time outdoors without adequate eye protection have substantially higher rates. The name “surfer’s eye” comes from the combination of UV exposure and the dry, wind-exposed environment surfers spend time in, though the condition is far more widespread than that group.
Age plays a role too. Pterygia typically appear in adults over 30, reflecting the cumulative nature of UV damage. There is a genetic predisposition in some families. Dry eye disease frequently coexists and can make symptoms worse – the unstable tear film irritates the pterygium and vice versa.
Symptoms
Many people discover a pterygium when they notice a visible growth in the mirror, or when someone comments on the appearance of their eye. Symptoms when present include:
- Persistent redness, particularly at the medial corner of the eye
- A sensation of grittiness or a foreign body
- Dryness and irritation, often worse in wind or air conditioning
- Blurred vision, particularly if the growth distorts the corneal surface
- Induced astigmatism causing progressive blurring or doubling of images
- Occasional tearing or light sensitivity during active growth phases
The growth is usually slow but not always predictable. Some pterygia remain stable for years; others progress steadily. Periods of rapid growth can occur, particularly after UV exposure or in dry, irritating conditions. Pain is not typical – if an eye with a pterygium becomes acutely painful, something else is going on.
Diagnosis and Monitoring
Diagnosis is clinical – a slit-lamp examination is all that is needed. The ophthalmologist will measure how far the growth extends onto the cornea, assess the quality of the corneal surface, and check for induced astigmatism. Corneal topography is useful when significant astigmatism is suspected, providing a detailed map of corneal curvature changes caused by the pterygium’s pull.
Monitoring matters. A pterygium that is small and stable today might be approaching the visual axis in two years. Most ophthalmologists recommend annual review for established pterygia, with more frequent monitoring if growth appears to be active.
Treatment
Lubricating drops and UV protection
For a small, stable pterygium that isn’t affecting vision, conservative management is entirely appropriate. Preservative-free lubricating drops reduce irritation and dryness. Wearing UV-blocking wraparound sunglasses outdoors is the most important thing a patient can do to slow progression and reduce the likelihood of recurrence after surgery. Mild inflammation can be managed with short courses of topical anti-inflammatory drops, but these are not a long-term solution.
Conjunctival autograft – the current standard
Surgery is performed when the pterygium is encroaching on the visual axis, causing visually significant astigmatism, producing intolerable symptoms, or continuing to grow. The pterygium is excised and the bare area is covered with a graft of healthy conjunctiva taken from the upper part of the same eye. This conjunctival autograft technique has substantially lower recurrence rates than the older bare-sclera method, where the sclera was simply left exposed after excision. Mitomycin C, an antiproliferative agent, is sometimes applied during surgery to further reduce recurrence risk. The procedure is typically done under local anaesthesia as a day case.
UV protection is not optional
Recurrence is the main concern after pterygium surgery. Even with autograft, 5–10% recur, and recurrent pterygia are more aggressive and harder to treat than primary ones. The most important thing a patient can do postoperatively is consistent UV protection – good quality sunglasses worn regularly, especially outdoors. Steroid drops in the postoperative period reduce inflammation and recurrence risk.
Pterygium and Dry Eye: An Uncomfortable Combination
Pterygium and dry eye disease frequently occur together and each makes the other worse. The pterygium disrupts the smooth corneal surface that a stable tear film depends on, while dry eye irritation promotes inflammation and may stimulate pterygium growth. Managing both simultaneously produces better outcomes than treating only the visible lesion.
Patients with significant dry eye should have this addressed before pterygium surgery – dry eye increases surgical discomfort, slows healing, and may contribute to recurrence. Similarly, after surgical removal, dry eye symptoms often improve as the smooth corneal surface is restored. The overlap with cornea and refractive surgery specialists is considerable here, particularly when the pterygium has induced significant corneal changes.
See Your Ophthalmologist If You Notice
- A change in vision – blurring or distortion that is new or worsening
- Rapid growth of a known pterygium over weeks to months
- Significant redness and discomfort that doesn’t respond to lubricating drops
- The growth appearing to cross the pupil margin
- Any pigmented lesion on the conjunctiva – pterygia are not pigmented, and any dark lesion needs prompt assessment to exclude conjunctival melanoma
Frequently Asked Questions About Pterygium
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Does a pterygium always need surgery?
No. Most small pterygia are managed conservatively for years or indefinitely. Surgery is reserved for pterygia that are growing toward the visual axis, causing significant astigmatism, or producing symptoms that affect daily life. Having a pterygium doesn’t automatically mean you need an operation – but it does mean you should have it monitored regularly.
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Will it grow back after surgery?
It can. With the modern conjunctival autograft technique, recurrence rates are around 5–10%. Recurrent pterygia tend to be more aggressive than the original. Consistent UV protection postoperatively is the single most important factor in reducing recurrence. Patients who go back to working outdoors without adequate eye protection have much higher rates.
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Can a pterygium make you go blind?
Not in the way most people mean. A pterygium can cause significant visual impairment if it grows to cover the pupil or induces severe corneal astigmatism, but these situations are addressed by surgery. The key is not letting it reach that stage. Regular monitoring and timely surgery when indicated prevent serious visual loss.
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Is a pterygium the same as a cataract?
No – completely different. A cataract is a clouding of the lens inside the eye. A pterygium is a surface growth on the white of the eye extending onto the cornea. They can coexist in the same patient but are unrelated conditions requiring different treatments.
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How do I stop my pterygium from growing?
UV protection is the primary tool. Wraparound sunglasses with UV-blocking lenses worn consistently outdoors, a hat with a brim, avoiding prolonged exposure to wind, dust, and dry environments. Keeping dry eye under control with lubricating drops also helps by reducing the chronic irritation that can stimulate growth. There’s no medication that stops a pterygium from growing – protection and monitoring are what matter.
The American Academy of Ophthalmology’s pterygium page gives a clear patient overview of the condition and its treatment options. For detailed surgical outcome data, the published literature on conjunctival autograft techniques gives a thorough account of why autograft has become the standard of care. Our cornea and refractive surgery section covers the broader range of conditions affecting the front of the eye.