This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cornea, Subject name: Ophthalmology
KF ring is seen in - 
Select and explain. 
A. Chalcosis, B. Diabetes mellitus, C. Keratoconus, D. Anterior Uveitis
A: Chalcosis
Answer: A: Chalcosis 
Explanation: Ans. is 'a' i.e., Chalcosis Chalcosiso Chalcosis is perforating injury to eye with metal containing copper (Cu). o Copper deposition can lead toi) Grayish-green/golden brown discoloration of peripheral cornea called Kayser-Fleisher ring.ii) Sunflower (Petal of flower) cataract due to deposition of copper under the posterior capsule of the lens.iii) Golden plaque at posterior pole of the retina.