Glaucoma is a group of eye diseases that cause glaucomatous optic nerve damage and visual field defects when the intraocular pressure exceeds the limit that the tissues in the eye, especially the optic nerve, can withstand. IOP is the pressure generated by the contents of the eye, including atrial fluid, crystal, vitreous humor, and intraocular blood, on the wall of the eye. Normal IOP values range from 10-21 mmHg. IOP can fluctuate 24 hours a day, but not by more than 5 mmHg, and the difference in pressure between the two eyes is less than 5 mmHg. What is the risk of glaucoma blindness? Glaucoma is the second most blinding eye disease in the world, and it is irreversible blindness. The risk of glaucoma causing blindness in one and both eyes is related to the duration of the disease. Fifteen years after diagnosis, the risk of blindness is 50% for one eye and 20% for both eyes. The lifetime risk of blindness after diagnosis was 16 percent for binocular blindness and 43 percent for monocular blindness. A community-based glaucoma screening study in Beijing showed that about 60% of patients were unaware that they had glaucoma and most patients were diagnosed with glaucoma at an intermediate or late stage. So a significant proportion of glaucoma is very insidious and more dangerous. Glaucoma is the thief of light and can unknowingly lead to blindness in both eyes. Primary glaucoma is divided into two main categories: primary closed-angle glaucoma and primary open-angle glaucoma. Patients with primary closed-angle glaucoma often have pathophysiological features such as hyperopia and narrowing of the shallow anterior chamber, which can be triggered by anxiety, mood swings, staying up too late, or staying too long in a dimly lit environment. At the beginning, there can be nasal root and eye soreness, blurred vision, and iris vision at night when looking at incandescent bulbs, which can be relieved after rest and can be easily ignored. If timely consultation and timely laser treatment can prevent the acute attack of glaucoma. The acute attack of primary acute closed-angle glaucoma can have severe eye pain, headache, nausea, vomiting, and sharp loss of vision, which can lead to blindness within a few days if not treated in time. Primary open-angle glaucoma is divided into simple open-angle glaucoma and normal intraocular pressure glaucoma glaucoma. This type of glaucoma is mostly asymptomatic in the early stages, and when it develops to the middle and late stages before going to the hospital, the visual function is already severely damaged, and the doctor is often unable to help. In particular, normal intraocular pressure glaucoma, normal intraocular pressure, can still occur glaucoma, more insidious and deceptive. Family history of glaucoma, high blood pressure, diabetes, myopia, hyperopia, advanced age (over 60 years old), and long-term use of glucocorticoids are all high-risk factors for glaucoma. It is recommended that the above people visit the hospital regularly for screening to rule out and detect glaucoma early. Glaucoma screening includes slit lamp, fundus, IOP 24-hour IOP, ultrasound microbial microscopy, fundus photography, optical coherence tomography and other examinations. Glaucoma is a class of eye disease that is extremely harmful to visual function. The key to prevention is early detection, early diagnosis, and early treatment to ensure that we retain useful vision and quality of life during our lifetimes. Glaucoma patients need lifelong review.