**Core Concept**
Pilocarpine is a muscarinic receptor agonist used topically to treat glaucoma by increasing aqueous humor outflow. Its side effects are primarily due to its muscarinic agonist activity.

**Why the Correct Answer is Right**
Pilocarpine's side effects include miosis (constriction of the pupil), accommodation spasm, and increased salivation. These effects are caused by the activation of muscarinic receptors in the eye, leading to increased parasympathetic activity. The eye's ciliary muscles contract, causing the lens to thicken and focus light on the retina, while the pupils constrict to reduce light entry. Additionally, salivary glands are stimulated to produce more saliva.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because pilocarpine does not cause mydriasis (pupil dilation), which is the opposite of what occurs with its use.

**Option B:** This option is incorrect because pilocarpine can cause increased tear production, but this is not a common side effect of topical pilocarpine solution. However, it might be related to another option.

**Option C:** This option is incorrect because pilocarpine can cause increased lacrimation (tear production), but it is not the best answer in this context.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that pilocarpine's side effects can be mitigated by using shorter-acting formulations or by administering the medication at bedtime to minimize interference with daily activities.

**Correct Answer: A. Mydriasis**