This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cornea and sclera, Subject name: Ophthalmology
[{'content': 'Fleischer ring is due to \nSelect and explain. \nA. Iron deposition, B. Copper deposition, C. Aluminum deposition, D. Molybdenum Deposition', 'role': 'user'}, {'content': "Answer: A \nExplanation: (Refer: AK Khurana Comprehensive Ophthalmology, 6th edition, pg no. 194)Some confusion exists between Fleisher rings and Kayser-Fleischer (KF) ring. Kayser-Fleischer (KF) rings are caused by copper deposits and are indicative of Wilson's disease, whereas Fleischer rings are caused by iron deposits and are indicative of keratoconus.", 'role': 'assistant'}]