**Core Concept:**
Muscle resection in ophthalmology refers to the surgical removal of ocular muscles, typically the rectus muscles, which control eye movements. The goal is to correct various ocular disorders such as strabismus (misaligned eyes) and dystrophies affecting these muscles. Understanding the concept of muscle function, innervation, and the importance of maintaining binocular vision is crucial.

**Why the Correct Answer is Right:**
Muscle resection achieves its therapeutic effect by disrupting the balance between the forces generated by the rectus muscles. In conditions like strabismus, the excessive tonicity or imbalance between the antagonistic pairs of muscles (e.g., horizontal rectus muscles: superior and inferior rectus, medial and lateral rectus) leads to eye misalignment. By selectively removing the stronger muscle, the surgeon disrupts the muscle tonicity, causing the weaker muscle to overcompensate and realign the eyes. This is based on the principle of the antagonistic principle, where the removal of one muscle allows the remaining muscles to perform their function optimally, resulting in improved binocular vision.

**Why Each Wrong Option is Incorrect:**

A. **Supralimbal scar:** This is not a direct consequence of muscle resection but rather a potential complication due to incorrect surgical technique or infection.

B. **Increased muscle tension:** Removing a muscle would reduce its tonicity, not increase it. Surgeons aim to reduce excessive muscle tone, not enhance it.

C. **Reduced motility:** Muscle resection does not aim to impair eye motility, but to improve it by restoring the balance between antagonistic muscle pairs.

D. **Absence of tonicity:** Tonicity refers to the muscle's ability to contract and maintain its length. Removing a muscle reduces its tonicity, not eliminates it.

**Clinical Pearls:**

1. **Adequate surgical technique and planning are crucial:** In order to achieve the desired outcome of muscle balance and improved binocular vision, surgeons must meticulously plan the muscle to be resected based on the specific eye misalignment and its underlying cause.
2. **Postoperative rehabilitation:** Following muscle resection, patients may require vision therapy to retrain the eye muscles and improve binocular vision.
3. **Understanding the anatomy and physiology of the extraocular muscles:** The six extraocular muscles (rectus, oblique, and accessory) are crucial for understanding the surgical approach and anticipated outcomes.