Pituitary tumor affects the patient’s vision in the left eye, which needs to be considered for surgical treatment. Pituitary tumor causing patients to suffer from left eye vision loss is usually caused by the compression of optic nerve by pituitary tumor, which requires surgical resection of the tumor, and pathological biopsy is sent to clarify the nature of the tumor after surgery. Timely surgical resection of the tumor can avoid further compression of the optic nerve, which may lead to poorer and poorer vision or even blindness. Surgical methods include transnasal butterfly microsurgery and transfrontal craniotomy. Pituitary tumor is often a benign tumor, when the tumor is small, there may be no clinical symptoms, when the tumor is large, it can produce pressure on the surrounding tissues, and clinically, it mainly shows increased intracranial pressure, such as headache, dizziness, nausea and vomiting, and impaired vision and visual field. Patients with pituitary tumors are recommended to go to the hospital in time and be treated under the guidance of doctors so as not to miss the best time for treatment.