Which drug is a powerful mydriatic and cycloplegic that can take up to two weeks to wear off?

Atropine is recognized as a potent mydriatic and cycloplegic agent, which means it effectively dilates the pupils and temporarily paralyzes the ciliary muscle, resulting in blurred vision for near objects. One of the notable aspects of atropine is its duration of action, which can last from several days up to two weeks, depending on the dosage and individual patient factors. This prolonged effect is particularly significant in clinical settings where extended pupil dilation is desired for diagnostic procedures or therapeutic effects.

In contrast, other drugs like homatropine have a shorter duration of action, typically lasting just a few days. Tropicamide is known for its rapid onset and much shorter duration, generally lasting only a few hours. Phenylephrine, while effective as a mydriatic as well, does not provide the cycloplegic effect that atropine and the others do; it primarily dilates the pupil by stimulating alpha-adrenergic receptors. Therefore, when considering the powerful mydriatic and cycloplegic properties along with the extended duration of effect, atropine stands out as the correct choice.