Pilocarpine, which has been used since the 1870s, is a medication used to reduce pressure inside the eye and to treat dry mouth. As eye drops, this medication is used to manage angle closure glaucoma until surgery can be performed, ocular hypertension, primary open angle glaucoma, and to bring about constriction of the pupil following its dilation. Basically, Pilocarpine eye drop works by causing the pupil of the eye to shrink and decreasing the amount of fluid within the eye. However, due to its side effects, it is no longer typically used in the long term management. These side effects include irritation of the eye, increased tearing, headache, and blurry vision. There are also other side effects that you need to take into consideration, such as allergic reactions and retinal detachment. Bear in mind that the use of Pilocarpine eye drop is generally not recommended during pregnancy.