What are the risks of pterygium? Even a quiescent pterygium can affect the normal ocular surface structure and transient activity, resulting in abnormal tear film distribution, squamous conjunctival epithelial metaplasia, and recurrent dryness, congestion, tearing, stinging and burning sensation in the eye, requiring topical application of corticosteroids, non-steroidal anti-inflammatory drugs or artificial tears, but long-term application must be alert to the adverse effects of drugs. As pterygium progresses, in addition to producing more ocular irritation, pterygium can affect visual function by pulling and compressing the cornea, causing cis-regular astigmatism. And when the deepening of pterygium infiltration has reached deep stromal layer and formed scar, it is still difficult to recover to the best vision status after surgery, resulting in causing irreversible blindness, which brings a heavy burden to the society, family and individual.