This clinical study investigates whether virtual reality (VR)-based cognitive training can help prevent postoperative delirium (POD) in elderly non-cardiac patients with pre-existing cerebral small vessel disease (CSVD). With the global aging population undergoing more surgical procedures, POD has emerged as a serious complication in surgical patients that can prolong hospital stays and increase the risk of developing Alzheimer's disease. The study utilizes an innovative VR system that combines eye-tracking cognitive assessment with interactive rehabilitation games to evaluate and train patients' cognitive function before non-cardiac and non-intracranial operations. Conducted at Peking University Third Hospital and First Hospital, this research specifically targets patients undergoing general surgery, orthopedic surgery and other non-intracranial/non-cardiac procedures to determine if this technology-based intervention can effectively reduce POD incidence in this population while exploring its underlying mechanisms. The findings could lead to a practical solution for protecting cognitive health in elderly patients undergoing routine surgical procedures during recovery