Eye pain in glaucoma is usually distension, caused by increased intraocular pressure. This symptom is seen in all types of glaucoma (closed-angle, open-angle, secondary), and is especially noticeable in acute elevation of intraocular pressure, such as in acute closed-angle glaucoma attacks. Therefore, if a patient is diagnosed with closed-angle glaucoma, he or she should seek immediate medical attention once severe eye distension and pain occur. Acute closed-angle glaucoma is easier to detect because the onset of symptoms are obvious: rainbow vision (rainbow-like circles when looking at lights), eye pain, significant loss of vision, and eye congestion. In severe cases, there are headaches, nausea and vomiting, and even fever. Some patients are mistaken for “acute gastroenteritis”, “migraine”, “severe cold”, etc. 2/3 of patients with chronic closed-angle glaucoma have a history of recurrent attacks, with painful eye swelling, blurred vision and iris vision. 1/3 of patients with chronic closed-angle glaucoma have no conscious symptoms, and occasionally cover one eye before realizing that the vision of the other eye is severely impaired and the visual field is narrowed. Open-angle glaucoma has no symptoms in the early stage, and only when the lesion develops to a certain extent does eye distention and pain, visual fatigue, and headache appear, while the central vision is generally unaffected and the visual field gradually shrinks. Thus, chronic closed-angle glaucoma and open-angle glaucoma are more insidious, and are called the “thieves of vision”, and only when the disease progresses to an advanced stage do the symptoms appear that the patient can detect, but the best opportunity for treatment is lost at this time. However, the painful swelling of the eye is not always caused by glaucoma, for example, patients with hypertension may also experience this symptom due to elevated eye pressure, but without damage to the optic nerve. Some patients with visual fatigue and dry eyes may experience eye swelling and pain, but they need to rule out glaucoma before treating it accordingly. For patients who suspect glaucoma because of eye swelling, if the IOP is not high when the swelling attacks, visual field and fundus examination should be done to rule out glaucoma. In recent years, due to the increased frequency of computer and cell phone use, the number of patients with eye swelling and pain caused by visual fatigue is growing rapidly. It is common in people who work long hours at close range, such as students, editors, writers, etc. Eye pain usually consists of swelling or soreness, inability to open the eyes, and easy tearing, which often improves after rest. If there is refractive error (e.g., farsightedness, astigmatism), the difference between the refractive power of both eyes is large, and the adjustment power of the eyes decreases in old age, the feeling of eye pain and fatigue is more likely to occur if the glasses are not suitable.