The purpose of a glaucoma visual field examination is twofold: to detect the presence or absence of optic nerve damage and to monitor the progression of the disease. The presence or absence of optic nerve damage is determined by detecting the presence or absence of visual field defects. The diagnosis of glaucoma is not entirely determined by IOP. A high IOP alone without optic disc damage and corresponding visual field defects can only be diagnosed as hypertensive IOP. On the contrary, in normal IOP glaucoma, the IOP is normal and only optic disc changes and visual field defects are present. Therefore, visual field defects are one of the main indicators for the diagnosis of glaucoma, which is especially important in primary open-angle glaucoma. Patients with high IOP are not treated clinically, but the fundus and visual field are followed regularly and treated as soon as early optic disc damage and visual field changes appear. The technology of visual field examination has made great progress, especially the computer-aided visual field examination, which is significantly more accurate and reliable, and can accurately record and save the examination results for comparison. In patients receiving anti-glaucoma treatment, comparison of consecutive visual field examination results is a sensitive indicator of progression of the disease. Stable and unchanged visual field defects mean that treatment is effective, while progressive worsening of defects is an indication that treatment needs to be intensified. So, what exactly is the frequency of glaucoma visual field review? If a patient with glaucoma is not treated, the natural process from the appearance of visual field damage to complete blindness varies according to the level of IOP: about 14.4 years for those with IOP between 21 and 25 mmHg; about 6.5 years for those with 25 to 30 mmHg; and about 2.9 years for those with more than 30 mmHg. Therefore, patients with stable disease are generally reviewed every six months to a year, and those with faster progression or unstable IOP are reviewed every 2 to 3 months or even less. Since there are also short-term fluctuations and long-term fluctuations in visual field changes, a single review of visual field deterioration is not sufficient to suggest deterioration, and only multiple visual field reviews can minimize the effects of long-term fluctuations.