<prompt> All of the following drugs causes mydriasis except: March 2012PhenylephrinePilocarpineEpinephrineAtropine  <response>: Ans: B i.e.. Pilocarpine Cholinergic stimulation causes contraction of both the pupil the ciliary body, while sympathomimetic stimulation leads to dilatation of the pupil Anticholinergic dilates pupil causing mydriasis impair accommodation leading to cycloplegia Drugs uses Phenylephrine 5-10, a selective alpha-1 agonist, dilates pupil are used prior to fundus examination or retinal laser procedures Pilocarpine parasympathomimetic use in glaucoma is limited by the occurrence of miosis, browache accommodative spasm Epinephrine 1 adrenaline use is contraindicated in patients with narrow anterior chamber angles due to the mydriasis it produces. Commonly used cycloplegics anticholinerics are atropine 1, homatropine 2, cyclopentolate 1 tropicamide 0.5 