When it comes to eye diseases, many people think of “glaucoma and cataract”. People are not unfamiliar with the word glaucoma, but they may not know exactly what kind of eye disease it is and why they should pay attention to it. So, what is glaucoma? Glaucoma is an irreversible, blinding eye disease that causes damage to visual function because the pressure in the eye (intraocular pressure) exceeds what the optic nerve can tolerate. The eye, like a tire, must have a certain amount of pressure inside it in order to function properly, but when the pressure is too high, the tire will burst and the eye tissue will be damaged, manifesting itself as a visual field defect. When we talk to newly diagnosed glaucoma patients in the clinic, we often hear them say, “No way, my eyes are fine, my vision is 1.5, how can I have glaucoma? Actually, visual acuity is only one part of visual function, it is the clarity of our vision when we look at something. Visual function also includes another important basic component – the visual field. Visual field is the extent of what the eye can see when looking forward. In everyday life, a good field of vision is just as important as good visual acuity. Patients with a small field of vision often bump into each other because they can’t see objects around them, and they have close calls when crossing the street because they can’t see the cars coming and going on either side of them. Glaucoma begins with damage to the visual field only, which is manifested as a smaller and smaller range of vision, and only in advanced stages does it damage vision, so it is important not to judge whether an eye is diseased only by how well it sees. Whether or not a disease should be taken seriously by society and individuals depends on whether or not the disease is prevalent and whether it is harmful. Glaucoma meets exactly these two requirements. First, the prevalence of glaucoma is high, and it is currently the second most blinding eye disease in the international ranking after cataracts. It can occur at any age, but is commonly found in middle-aged and older adults. According to some data, the prevalence of glaucoma is about 1% in the overall population and about 3% in people over 45 years of age, and it is conservatively estimated that there are 66 million glaucoma patients worldwide. Second, glaucoma is a blinding eye disease. If patients with glaucoma are not treated effectively, depending on the type, the affected eye can go blind in a few days or a dozen days, or in a few years or a decade. It is important to emphasize that the blindness of glaucoma is irreversible, which means that current medical technology and techniques cannot restore the sight of patients who have lost their eyesight due to glaucoma. In contrast, cataracts, the number one cause of blindness, can be treated surgically to restore visual function. In this sense, glaucoma is a much greater threat to visual function than cataracts. You may ask, “Can we do anything to reduce the prevalence of glaucoma? Unfortunately, current technology is not yet able to reduce the occurrence of glaucoma, but it is possible to reduce the rate of glaucoma blindness. Our country is technologically advanced in the clinical treatment of glaucoma and is in step with international standards. With early detection, diagnosis and treatment, the vast majority of glaucoma patients can maintain useful visual function throughout their lives. The premise of early detection of glaucoma is that each of us can understand and pay attention to the dangers of glaucoma.