46-year-old man comes to the emergency department due to worse | Uworld | Step 1

46-year-old man comes to the emergency department due to worsening blurry vision, difficulty swallowing, and dry mouth for the past hour. He has also been having nausea and abdominal discomfort but has no headache or fever. The patient has no prior medical conditions and takes no medications. He smokes a pack of cigarettes daily but does not use alcohol or illicit drugs. The patient has not traveled recently but attended a community potluck event yesterday where he sampled home-canned foods. Physical examination shows bilateral ptosis and sluggish pupillary response.