There are various symptoms of high intraocular pressure (IOP). IOP is the pressure exerted by the contents of the eye on the wall of the eye. Under normal circumstances, IOP is stabilized within a certain range to maintain the normal shape and physiological function of the eye. The production and excretion of atrial fluid is a dynamic equilibrium, meaning that the total amount of atrial fluid produced and excreted is equal over a certain period of time. If for some reason the excretion of atrial fluid is blocked or the amount produced increases, this can lead to a buildup of atrial fluid and an increase in intraocular pressure. 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 IOP is <8mmHg in a 24-hour day. If it is higher than the above range, it is considered high IOP. Increased intraocular pressure can lead to eye swelling, increased fatigue, a feeling of soreness and swelling when the eyes are slightly used, and iris-like vision, i.e., a rainbow-like circle of light, mostly accompanied by ipsilateral headache and even nausea and vomiting, which can be easily confused with gastrointestinal diseases. Therefore, patients with high intraocular pressure can have a variety of symptoms, not just ocular symptoms, and should seek medical attention to determine the cause and receive appropriate treatment.