For how long can the effects of atropine in the eye last?

The effects of atropine in the eye can indeed last for several days. Atropine is a potent anticholinergic agent that works by blocking the action of acetylcholine on the muscarinic receptors in the eye, leading to pupil dilation (mydriasis) and paralysis of the ciliary muscle (cycloplegia).

When atropine is applied topically to the eye, it penetrates the tissues and binds to the receptors for an extended period. This prolonged binding is due to the compound's high affinity for the receptors and the slower rate at which it is metabolized and eliminated from the body, particularly when compared to other shorter-acting anticholinergic agents.

In clinical settings, atropine is often used in ophthalmology, for instance, during examinations or to prevent synechiae in inflammatory conditions. The lasting effects can significantly inconvenience patients, as it may blur vision and increase sensitivity to light for a substantial duration, often requiring several days for complete recovery. Hence, the choice indicating that the effects can last for days is accurate based on the pharmacokinetics of atropine.