A 3-year-old girl was presented to the local hospital with a 12-h history of ocular swelling and pain in her right eye. She lived with her grandmother, a farmer. The local doctor found a large number of yellow-brown granular foreign bodies in the conjunctival sac, conjunctival hyperemia, and edema. The doctor rinsed the conjunctival sac, but no other foreign bodies were found. On admission, an orbital CT scan revealed a metallic foreign body between the right eyelid and the eyeball (shown in ). Simultaneously, the symptoms worsened and yellow-brown foam appeared in the conjunctival sac. The foreign body was immediately removed under general anesthesia. During surgery, a button battery was found in the superonasal fornix, the local tissue was burned and necrotic, and the superonasal cornea showed flaky yellow-brown degeneration, which was considered to be caused by a burn (shown in ). The necrotic fascia and conjunctiva were removed after removal of the button battery. It had been 39 h since the onset of symptoms in the child. As in other cases, the child could not clearly express where the button battery came from and how it entered the eye. After the operation, the child was transferred to our department for further treatment. As the child did not cooperate with the examination, we performed a second surgery under general anesthesia to further understand whether the child had scleral dissolution and to prevent the occurrence of symblepharon. During surgery, the conjunctiva and fascia of superonasal fornix were absent, the sclera was exposed, and there was no necrosis (shown in ). We further removed the remaining necrotic tissue, then transplanted the amniotic membrane, and transferred the adjacent conjunctiva to cover it. Due to our surgery, the patient was exempted from daily separate the bulbar and tarsal conjunctiva treatment for the first week postoperatively. We have learned that button batteries may contain heavy metals. Previous literature has reported that button battery ingestion can cause mercury or lithium poisoning in the digestive tract []. To our knowledge, there have been no reports of heavy metal poisoning due to ocular exposure to button batteries. In this case, because the eye was exposed to a button battery for a long time, we tested for the heavy metal concentrations in the blood. The results showed that the blood mercury concentration was less than 1 μg/L, and the blood metallic lithium concentration was 0.00961 mmol/L, which did not reach the toxic level (>1.3 mmol/L []). We also tested for manganese and silver and found them to be within the normal range. The child had no symptoms of heavy metal poisoning. The girl was then given steroid eye drops 4 times daily and steroid eye ointment twice daily and gradually tapered over 3 months. After 3 months, her vision was severely impaired only the FC, and the cornea was opaque and had foci of flaky burn degeneration. Fortunately, there was only conjunctival pigmentation in the superonasal fornix and no symblepharon. The parents are satisfied with our treatment, even though the patient’s vision cannot be restored.