The changes in the pupils of subarachnoid hemorrhage are mainly manifested in the following ways: 1. If the hemorrhage is a simple subarachnoid hemorrhage, and the hemorrhage is located in the cerebral sulcus or gyrus, the convex surface of the brain, then the patient’s pupils can appear as bilateral pupils of equal size and roundness, with sensitive reflexes to light. 2. If the subarachnoid hemorrhage breaks into the ventricular system, such as the third or fourth ventricle, or the lateral ventricle, the patient will have pinpoint-like 3. If the subarachnoid hemorrhage is large and the patient has brain herniation, the pupils may be unequal in size, with one pupil dilated and the light reflex dull or absent, while the other pupil is normal. 4. Bilateral pupil dilatation and loss of light reflex. The pupillary changes in subarachnoid hemorrhage are mainly based on the size and location of the hemorrhage.