Normal IOP is 10mmHg-21mmHg (1.33kPa-2.80kPa) with a mean value of 15.8mmHg (1mmHg≈0.133kPa) and a standard deviation of 2.6mmHg, and the difference in pressure between the two eyes is <4mmHg-5mmHg (0.53kPa-0.67kPa), and the difference in pressure between the two eyes is <8mmHg in a 24-hour day. If it is higher than the above range, it is generally considered as high IOP. High IOP is an important indicator of eye abnormalities, and we should not take it lightly if IOP increases. Generally speaking, the most common cause of elevated IOP is glaucoma, a serious blinding eye disease that can cause irreversible vision loss or even blindness if left untreated. Therefore, if there is high intraocular pressure, the first step is to determine whether it is glaucoma, and if it is, to treat it as soon as possible. The main purpose of treatment is: to lower IOP, reduce eye tissue damage, and protect visual function. There are several methods to control IOP: 1) medication: eye drops, oral carbonic anhydrase inhibitors and other IOP-lowering drugs, and dehydrating agents such as mannitol; 2) laser treatment: YAG laser iridotomy; 3) surgery: anti-glaucoma surgery (atrial angle dissection, trabeculectomy, glaucoma adjustment valve implantation, etc.). IOP control by one of the above methods (one of them or in combination).