High intraocular pressure (IOP) refers to the pressure of the contents of the eye on the wall of the eye being higher than the average normal value for the population. High IOP is divided into two conditions: true high IOP and pseudo high IOP. Genuine high IOP may be glaucoma, which requires a comprehensive analysis combined with multiple IOP measurements, visual field examinations, fundus examinations, etc. After the diagnosis of glaucoma is confirmed, the IOP needs to be controlled with medication or surgery to slow down the progression of glaucoma; it may also be hypertelorism, which is mostly seen in developing adolescents and shows only high IOP, dynamically observed for several years, without visual field damage and enlarged fundus cup-to-disc ratio and other glaucomatous manifestations, which do not require treatment and do not cause any ocular damage. Pseudophakic hypertension may be related to the patient’s nervousness and squeezing of the eyes during the measurement, instrument measurement errors, and the patient’s corneal thickness being higher than the average. The operation should be standardized during the measurement and examination, and the patient should be asked to take sufficient rest and measure in a relaxed state, and a more accurate IOP meter should be replaced, such as using a flattening IOP meter under surface anesthesia and performing corneal thickness measurement to correct the measured IOP value according to the thickness of the cornea. If the IOP is pseudohypertension, no special treatment is needed. In conclusion, there are many causes of high IOP, which need to be determined after a comprehensive analysis by going to the ophthalmology department for relevant examinations and follow-ups, and then taking appropriate countermeasures.