<prompt> Antitubercular drug causing ophthalmic toxicity is:IsoniazidRifampicinEthambutolNone of above  <response>: 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. 