What potential effect does long-term Pilocarpine use have on vision?

Long-term use of Pilocarpine can lead to a myopic shift in vision due to its mechanism of action as a muscarinic agonist. Pilocarpine primarily stimulates the ciliary muscle, leading to increased accommodation. As a result, this enhanced accommodation can make the eye more nearsighted, or myopic, because the lens focuses images better on the retina for close objects.

This myopic shift occurs typically because the constant stimulation and contraction of the ciliary muscle can lead to changes in the eye's overall refractive state. The eyes may adapt over time to these conditions, causing a greater tendency to focus on nearer objects while the ability to focus on distant objects may decline slightly.

Other potential effects of Pilocarpine, such as changes in glare sensitivity and peripheral vision, are less significant in the context of long-term use. While Pilocarpine can affect pupil constriction and visual comfort, the predominant and clinically relevant effect observed in many patients under long-term treatment is indeed this shift towards myopia. Therefore, understanding the pharmacological outcomes of Pilocarpine helps explain the association with a myopic shift.