Abstract Background We report a case of acute onset of cataract after eyelid rejuvenation tightening with intense focused ultrasound (IFUS) treatment without using a protection device. Case presentation A 47-year-old female patient presented at the outpatient clinic with blurred vision in her left eye immediately after undergoing an eyelid tightening procedure, using IFUS, seven days prior. The patient had decreased vision in her left eye, caused by an acute cataract with several drop-like opacities and a rosette-like posterior subcapsular cataract. One month after her first visit, the patient’s visual acuity in her left eye decreased to 20/630. A Swept-Source Anterior Segment optical coherence tomography confirmed that the posterior capsule was not ruptured. The patient underwent uneventful phacoemulsification cataract surgery with intraocular lens implantation, which resulted in full visual recovery. Conclusions This case emphasized the need to evaluate possible ocular side effects, resulting from periocular IFUS without a protection device, including severe cataract requiring surgery.