Symptoms of a pituitary tumor compressing the optic nerve can primarily affect vision. A pituitary tumor that grows saddle up or compresses the optic nerve or optic cross has the potential to significantly affect vision. Some patients may have decreased visual acuity, some may have visual field defects, and in severe cases, blindness may occur in both eyes. This situation is mainly related to the size of the tumor, but also related to the location and direction of the growth of the pituitary tumor. Some pituitary tumors are not particularly large, but the direction of growth is more inclined to compress the optic nerve, which is prone to impaired vision. Some patients often take vision loss or visual field defect as the reason for their first visit to the doctor, and tumor growth in the pituitary gland is often found during cranial magnetic resonance, which is a situation that needs to be paid attention to.