The manifestations of the disease are varied, and if the following symptoms occur then there is a high probability that glaucoma is present 1. Headache: Headache that cannot be relieved by sedative and pain relieving drugs. Because glaucoma headache is caused by the pressure of the eye tissue, it can be reduced or eliminated only after the pressure of the eye drops. Glaucoma headache is often accompanied by orbital and nasal root swelling pain, and the headache in one eye may also be manifested as severe migraine. 2. Visual impairment: one of the diagnostic criteria for glaucoma, glaucoma disease has significant vision loss during acute attacks. In addition to corneal edema, the main cause is the damage to the optic nerve caused by the increase in intraocular pressure. The higher the intraocular pressure, the greater the pressure on the optic nerve, and the more pronounced the vision loss. Some early patients do not have obvious vision loss, but only foggy vision and blurred vision at night, which disappears the next day after a good rest, are the precursor symptoms of glaucoma onset, which should not be ignored. 3. iris vision: one of the diagnostic criteria for glaucoma, is that when the patient develops, there is a rainbow-like circle of light around the light when looking at it. The outer circle is red and the inner circle is green or violet-blue. This is due to increased intraocular pressure, which causes corneal edema due to impaired fluid circulation in the eye and produces refractive changes. When the eye pressure returns to normal, the iris disappears. However, iridophoria is not unique to glaucoma and can occur with cloudy lens or conjunctival secretions, although the hue is not as sharp as typical iridescence. It is also not as episodic as the iris of glaucoma and is not accompanied by symptoms such as headache. 4, nausea and vomiting: one of the diagnostic criteria for glaucoma, nausea and vomiting caused by gastrointestinal disorders are also common, but they are also often accompanied by symptoms such as abdominal pain or changes in the number of bowel movements, which can mostly be relieved with anti-vomiting and analgesic drugs, which can be differentiated. In contrast, nausea and vomiting during glaucoma attacks will only be reduced or eliminated when the IOP drops. Sometimes after vomiting, the IOP can fall and there is a momentary improvement, but the IOP is still high, and the iris and headache are still there. 5, IOP is an important basis for the diagnosis of glaucoma, but it is not the only factor, you can not mechanically determine whether glaucoma by the level of IOP. Clinically, there is a kind of glaucoma until blindness, the IOP is still within the normal range, we call it “low IOP glaucoma”, this is because its own basic IOP is low, even in the range of fluctuations in normal IOP, it is enough to cause damage to the fundus of the eye. There is another kind of high intraocular pressure, but there is no clinical manifestation of glaucoma and IOP destruction, we call it “high IOP”, only 10% of these people develop glaucoma. Therefore, IOP is an important and indispensable basis for the diagnosis of glaucoma, but it is not the only basis. IOP needs to be checked at a regular hospital.