The triangular-shaped flesh-like tissue with many blood vessels inside is called pterygium because it resembles the wings of an insect, and in Chinese medicine it is called pterygium pandorum. The disease is more common in people who work outdoors for a long time, such as farmers, fishermen, and salt workers, whose eyes are often irritated by dust, ash, sand, and sunlight, making them susceptible to the disease. Pterygium does not affect vision and does not cause any discomfort in the eyes, but when the pterygium reaches the center of the cornea and blocks the pupil, it can cause vision loss. However, if not treated properly, it can lead to recurrent attacks and even blindness. Pterygium mostly occurs on the inner side of the cornea, but some grow on the outer side. It can be divided into three parts: the tip of the pterygium, which is fixed to the cornea, is called the head; the grayish-white, slightly elevated part, which grows at the edge of the cornea, is called the neck; and the fan-shaped part of the white bulbous conjunctiva, which has many blood vessels on its surface, is called the body; there are two types of pterygium: progressive and stationary. The body and neck of a pterygium are congested, hypertrophied, and have a distinctly elevated head with a grayish-white edge at the front. It gradually grows toward the center of the cornea. The other type of pterygium stops at a certain point, is not congested, is thin, has a flattened head, and is in a resting state. Another type of pterygium, which can grow anywhere on the edge of the cornea, is usually small and thin, not congested, grayish, and does not develop. It is formed when there is an ulcer or trauma to the edge of the cornea, and it adheres to the corneal wound due to a high degree of edema in the nearby conjunctiva. This type of pterygium is called a pseudopterygium and it is completely different in nature from the pterygium described earlier. Patients with pterygium have no conscious symptoms, but they do not look good. When the pterygium progresses toward the center of the cornea, it can cause astigmatism, and if it obscures the pupil, it can seriously affect vision or blindness. A thick contracted pterygium can restrict eye movement and even cause diplopia. When inflammation is evident, photophobia, tearing, and foreign body sensation may be present. The goal of pterygium treatment is twofold: 1. to remove the pterygium and improve the symptoms. 2. Cosmetic treatment. How should a pterygium be treated? 1. Quiescent phase: No treatment is necessary for asymptomatic. When there is inflammation, anti-inflammatory eye drops should be ordered, especially hormonal eye drops are more effective, but should be used under the guidance of a doctor. 2. Progressive phase: Generally, the above medications are used first, and surgery should be performed after the congestion of pterygium is controlled, but there is a recurrence rate of 15% to 30% after surgery. Some measures are also used after surgery to prevent recurrence. Recurrence of pterygium after surgery is the biggest problem in the treatment of this disease. There are many surgical methods for this disease, and pterygium excision combined with corneal limbal stem cell transplantation is more effective. Aggressive control of inflammation and prevention of congestion before and after surgery are also key to treatment.