Which of the following is an example of a mydriatic?

A mydriatic is a substance that causes the dilation of the pupils. Neo-Synephrine, which is the correct answer, contains phenylephrine, a synthetic substance that acts as an adrenergic agonist. When applied topically to the eye, it stimulates the dilator muscle of the iris, leading to pupil dilation. This property makes it useful in ophthalmology, particularly for diagnostic procedures and therapeutic uses.

Atropine can also cause dilation of the pupils; however, it primarily acts as an anticholinergic rather than a classic mydriatic. While pilocarpine is a medication used to treat glaucoma and works by constricting the pupil, it is not a mydriatic since it does the opposite of what dilators do. Timolol is a beta-blocker that is used in managing intraocular pressure in glaucoma but does not cause pupil dilation.