Early 20th century ophthalmology drugs. Ophthalmology is the study of the eye and its disorders and their treatment. Dating from the first decade of the 20th century, there are three coloured drug bottles here, labelled with their contents (atropine, eserine, euphthalmine). At left is an undine bottle, designed to be used to add drops of a drug to a patient's eye. Atropine and euphthalmine are both used to dilate (enlarge) the pupil of the eye, while eserine is used for the opposite effect, to contract the pupil of the eye. The dropper bottle is named for undines (also called ondines), water nymphs found in European folklore.