The concept of glaucoma Glaucoma is a group of diseases characterized by characteristic optic nerve atrophy and visual field defects as a common feature, and pathologically increased intraocular pressure is its main risk factor. Manifestations of glaucoma Glaucoma is divided into three main categories: primary, secondary and congenital. Different types of glaucoma have different clinical manifestations, such as: acute closed-angle glaucoma with a major attack will manifest as eye distension and pain, eye redness, photophobia, vision loss, accompanied by severe headache on the same side, and some patients will also have nausea and vomiting; while patients with chronic closed-angle glaucoma and open-angle glaucoma often have few symptoms and will gradually lose their eyesight without realizing it. The clinical manifestations of secondary glaucoma vary depending on the primary disease. How can I tell if I have glaucoma? Glaucoma is determined by the patient’s intraocular pressure, visual field, atrial angle, and fundus performance, as well as by the patient’s symptoms, medical history, and family history. Does high eye pressure mean glaucoma? In patients with glaucoma, the IOP is usually higher than normal (the normal value of IOP is 10-21 mmHg), however, it cannot be simply understood that high IOP is glaucoma. In some patients, although the IOP is above the upper limit of normal (the range of normal IOP is 10-21 mmHg), there is no damage to the optic nerve or visual field. This condition cannot be called glaucoma and does not require medication. Recommendation: Glaucoma is an eye disease that can lead to blindness, therefore, once it is diagnosed as glaucoma, it is important to use medication as prescribed by the doctor even if there are no symptoms.