Hirsutine nitrate eye drops work by lowering intraocular pressure. Hirsutine acts by directly stimulating muscarinic receptors located on the pupillary sphincter, ciliary body and secretory glands. By contracting the pupillary sphincter, it causes the peripheral iris to leave the anterior wall of the atrial angle, opening up the angle and increasing aqueous drainage. At the same time can also be through the contraction of the longitudinal fibers of the ciliary muscle, increase the scleral protrusion tension, so that the trabecular meshwork gap is open, the resistance to atrial aqueous drainage is reduced, increasing atrial aqueous exclusion, reducing intraocular pressure. Hirsutine nitrate eye drops are used for acute closed-angle glaucoma, chronic closed-angle glaucoma, open-angle glaucoma, and secondary glaucoma. It can be used in combination with other pupil shrinkers, beta-blockers, carbonic anhydrase inhibitors, sympathomimetic drugs or hypertonic dehydrating agents for the treatment of glaucoma. After ophthalmoscopy, eye drops may be used to shrink the pupil to counteract the effects of ciliary muscle paralyzers or dilators. This drug may cause tingling, burning sensation, conjunctival congestion causing ciliary spasm, superficial keratitis, temporal or periocular headache and other adverse reactions, and should be used under the supervision of a physician. This drug is contraindicated in patients with any ophthalmic disease that should not be pupil reduction, such as iridocyclitis, pupillary block glaucoma, etc.; contraindicated in people who are allergic to any of the ingredients of this product.