The main causes of pterygium in the eye include ultraviolet light, chronic inflammation of the eye, viral infection, and genetic factors. 1. Ultraviolet light: Ultraviolet light exposure is a common cause of pterygium of the eye, because ultraviolet light exposure can lead to lesions on the surface of the patient’s eyeball. 2. Chronic inflammation of the eyeball: if the patient’s eyeball is stimulated by pollen, wind and sand for a long time, it can lead to chronic inflammation of the surface of the eyeball, which may make the patient’s eye grow pterygium. 3. Viral infection: Herpes simplex virus infection can increase the risk of pterygium in the patient’s eye. 4. Genetic factors: mutations in the P53 gene may also increase the risk of pterygium. In addition to the above factors, fishermen, farmers, construction workers, etc., which are exposed to ultraviolet light for a long time, and the eyeballs are easily irritated by foreign objects, are also prone to pterygium. It is recommended that patients who develop pterygium in the eye should seek prompt medical attention to evaluate their condition and follow the doctor’s instructions for treatment.