The retina is the only part of the body where the pattern of small blood vessels can be directly observed. The retinal vascular system is affected by hypertension with corresponding damage, and these fundus changes are called hypertensive retinopathy. A fundus examination can detect hypertensive retinopathy, provide a general estimate of the extent of damage to the vascular system caused by hypertension, and guide the treatment of hypertensive disease. For patients with particularly high blood pressure or even malignant hypertension, fundus examination has a more important significance. The blood pressure measured in the outpatient clinic is often after the onset of the disease or after the use of medication, when the blood pressure has dropped considerably compared to the onset of the disease. A fundus examination that reveals characteristic changes – cotton wool spots – indicates a diastolic blood pressure greater than 110 mmHg at the onset of the disease, while an edema of the optic disc in the fundus indicates a blood pressure of 250/150 mmHg at the onset of the disease – that is, malignant hypertension. Funduscopy can also detect other fundus diseases associated with hypertension, such as retinal artery blockage, venous blockage, and ischemic optic neuropathy, facilitating early detection and treatment of the disease.