This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti Microbial, Subject name: Pharmacology
Antitubercular drug causing ophthalmic toxicity is: 
Select and explain. 
A. Isoniazid, B. Rifampicin, C. Ethambutol, D. None of above
C: Ethambutol
Answer: C: Ethambutol 
Explanation: Ans, C EthambutolOptic neuritis due to ethambutol:* Reversible* Loss of red green color discrimination* Central scotomasExtra Edge points:Rifabutin and Rifampin can also orange tan discoloration of tears and contact lenses.