A pterygium is a small triangular shaped growth that occurs on the front surface of the eye. It starts on the white part of the eye (the outer lining called the conjunctiva) and then grows onto the cornea – the usually clear front surface of the eye.
It is caused by exposure to ultraviolet rays from sunlight and is therefore is more common in people who work outdoors or spend a lot time in the sun. Sometimes a pterygium causes eye irritation or redness. Rarely it grows to the centre of the cornea to causing blurred vision. The only way to treat a troublesome pterygium is to surgically remove it, which is normally performed under local anaesthetic.