
Most active ingredients in presbyopia-correcting eye drops, including pilocarpine, aceclidine, and carbachol, are direct-acting cholinergic agonists that activate the iris sphincter muscle, causing pupil constriction.

Most active ingredients in presbyopia-correcting eye drops, including pilocarpine, aceclidine, and carbachol, are direct-acting cholinergic agonists that activate the iris sphincter muscle, causing pupil constriction.