The cause of the flashing sensation after retinal detachment surgery is complex. It may be caused by the vitreous body pulling on the retina or by gas or silicone oil filling the vitreous cavity irritating the retina, which is related to the patient’s condition and surgical procedure. If the retinal detachment is treated with scleral buckling surgery without removing the vitreous body, the vitreous body in the eye may have pulled on the retina to varying degrees after the surgery, thus stimulating the retinal cells, which in turn triggers the flashing sensation in front of the eyes of the patient, and the patient needs to go to the hospital for follow-up checkups on a regular basis in order to avoid recurrence of the retinal detachment. After vitrectomy, the vitreous cavity will be filled with gas or silicone oil, which may irritate the retina and cause the patient to experience flashes of light. It is recommended that postoperative retinal detachment patients follow their doctor’s instructions, have regular checkups, and seek prompt medical attention when discomfort occurs.