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substances that cause dilation of the pupil, or mydriasis, by increasing the tension of the radial fibers of the iris (sympathomimetics) or by decreasing the tension of the pupillar sphincter (M-cholinolytic substances, such as atropine, which also cause paralysis of accommodation). Mydriasis may also be caused by synthetic mydriatics.
Mydriatics are used as therapeutic agents (causing functional rest in acute inflammatory diseases and traumas of the eye) and for diagnostic purposes (for example, during examination of the fundus oculi). Mydriatics are applied in the form of solutions or ointments to the conjunctival sac of the eye. The use of mydriatics to treat glaucoma is contraindicated, since mydriatics increase intraocular pressure.