Recently, a nationally renowned glaucoma expert, Prof. Yuan Yansheng, came to Tianjin to give a presentation on his many years of experience in glaucoma research and treatment. The highest goal of glaucoma treatment is to protect visual function (vision, visual field, optic nerve). The relationship between intraocular pressure (IOP) and optic nerve damage has been found to be as follows: IOP at 20-24 mmHg with 3% loss of optic nerve per year; IOP at 25-29 mmHg with 7% loss of optic nerve per year; IOP at 30-34 mmHg with 14% loss of optic nerve per year; IOP at 35-39 mmHg with 52% loss of optic nerve per year; and IOP at 40 mmHg or more with >60% loss of optic nerve per year. The optic nerve loss is >60% per year for IOP of 40 mmHg or more. The reduction of visual field and damage to the optic nerve caused by glaucoma is irreversible, so the treatment of glaucoma should be aimed at lowering intraocular pressure and protecting visual function. After long-term observation, glaucoma IOP at 12.3mmHg, long-term observation of the visual field is stable, IOP at 14.7mmHg, the third year the visual field began to slowly shrink, and IOP at 16.9mmHg, the third year the visual field damage began to progress significantly. Therefore, patients with glaucoma should observe the intraocular pressure, monitor the changes of the visual field and optic nerve, and adjust the treatment program in time.