Intraocular pressure (IOP) is the pressure of the contents of the eyeball on the wall of the eyeball. The normal value of IOP is usually around 10 mmHg to 21 mmHg, and patients may have elevated IOP, but there is no maximum value. When glaucoma patients develop, intraocular pressure will be elevated, the severity of the disease is different, the magnitude of the elevation is also different, and there is no maximum value. Normally, IOP should fluctuate between 10 mmHg and 21 mmHg. Intraocular pressure is one of the important monitoring indicators when performing eye examinations, and refers to the pressure exerted by the aqueous humor, vitreous humor, and other contents inside the eyeball on the wall of the eyeball. If the IOP is too low, it can easily cause atrophy of the eyeball, while too high IOP can lead to atrophy of the optic nerve, which can lead to blindness if not treated in time. It is recommended that patients with abnormal intraocular pressure seek medical attention to evaluate their condition and follow the doctor’s instructions for treatment.