Pterygium is a benign tissue growth on the surface of the eye. If untreated it has the potential to affect your vision by covering your pupil or by causing astigmatism.

What is pterygium?

A pterygium is a benign conjunctival tissue growth on the surface of the eye. Typically, it begins as a small reddened and thickened area in the corner of the eye – usually the corner that’s closest to the nose - and is most commonly triangular in shape. It can often extend across the surface of the cornea.  Not only can it look unattractive, but also if left untreated it has the potential to affect your vision by covering the pupil or creating astigmatism.

What are pterygium symptoms?

The symptoms of pterygium vary from person to person. Some people may not experience any symptoms at all, but can see a fleshy raised area on their eye. Others may experience symptoms that include dryness, irritation, inflammation and redness, or a gritty feeling like there is a foreign object in the eye. They can also make it more difficult or uncomfortable to wear contact lenses. If the pterygium extends onto the cornea it can cause blurred vision if the curvature of the cornea is altered, and it can also obscure your vision.

What are the causes of pterygium?

There are a number of causes that may contribute to a person developing a pterygium, but the most significant contribution is exposure to increased amounts of UV light. It is much more common for those living in sunny areas and in people whose profession exposes them to UV light – like arc welders, farmers and sailors. The risk of pterygia forming is higher in countries like New Zealand as we are in an area where there is less filtering of UV light because of the hole in the ozone layer. Environmental irritants like dust, wind and air pollution are also possibly connected to pterygia diagnoses, as are hereditary factors.

Is pterygium painful?

Thankfully, a pterygium is generally not painful, unless it becomes inflamed.

Can you prevent pterygium?

The best way to try and prevent a pterygium forming is to reduce the risk of being exposed to the elements by wearing sunglasses that provide good coverage and a hat when outdoors. If you work in a profession where your eyes are exposed to high amounts of UV light, use appropriate safety equipment and eye wear. People who spend a lot of time on the water or snow should be extra careful to protect their eyes from UV light. If you’ve already had a pterygium diagnosed, protecting your eyes from UV light can help limit the progression of grows.

What is a pinguecula on the eye?

A pinguecula (or pingueculae for more than one) is very similar to a pterygium and the two are often confused. However, a pinguecula is a small raised area that occurs only on the conjunctiva, which is the thin, protective membrane that covers the surface of the eye, and it does not grow across the cornea.

How do you diagnose pterygium?

A pterygium is usually diagnosed from its distinctive appearance. It can be confused with a pinguecula, especially in its earlier stages. Seeing an eye specialist is the easiest way to gain an accurate diagnosis. Any eye troubles should be seen by a professional, as it could be something more serious.

Pterygium Treatment

Eye Drops

Treating pterygia varies depending on the size, nature and symptoms of the pterygium. There are two main treatments, the use of eye drops and surgery. Eye drops may be used to reduce any redness or irritation. Where dryness of the eye is a problem, eye drops are used as well, to keep the eye lubricated.


Surgery is an option especially when vision is affected or your symptoms are problematic. Surgery involves the pterygium being carefully removed and a graft – taken from the conjunctiva (the transparent skin that covers the eye) - being put over the same area where the pterygium was. If you do need to have your pterygium surgically removed, it will be under a local anaesthetic and it takes about 30 minutes to perform. Post-surgery, eye drops and eye ointment are prescribed to prevent infection, keep your eye lubricated and assist with healing. It is possible that the pterygia may recur after removal although this only occurs in a small percentage of cases.