Atropine eye drops are used to temporarily paralyze the accommodation reflex and as a long-lasting pupil dilating agent, or mydriatic. what action of atropine causes the dilation effect? atropine eye drops are used to temporarily paralyze the accommodation reflex and as a long-lasting pupil dilating agent, or mydriatic. what action of atropine causes the dilation effect? blocks contraction of sphincter pupillae muscle decreases contraction of dilator pupillae muscle increases contraction of sphincter pupillae muscle enhances parasympathetic responses by intrinsic eye muscles