Isopto Homatropine contains homatropine hydrobromide which blocks the action of certain parasympathetic nerves and cholinergic drugs. In ophthalmology, homatropine is used for its mydriatic and cycloplegic effects. Its peripheral effects are much weaker than those of atropine. It is preferred to atropine for diagnostic purposes because its action is more rapid, less prolonged and is readily controlled by physostigmine. The effect is exerted in 15 to 30 minutes and passes off in 12 to 24 hours. In children homatropine does not usually produce complete paralysis of accommodation.