What is pilocarpine, used in eye drops that reduce need for reading glasses in 15 minutes?

PresVu eye drops, approved by DCGI, improves near vision in 15 minutes, claimed Entod Pharmaceuticals. It contains 1.25% pilocarpine hydrochloride. Eye surgeon Dr Maansi Sethi said pilocarpine is a lactone alkaloid used in ophthalmology to reduce intraocular pressure and manage various eye conditions. By constricting pupils, pilocarpine increases depth of field, improving near vision, she added.