Certified Paraoptometric (CPO) Practice Exam 2025

Which extraocular muscle is the most powerful and turns the eye toward the nose?

1. Lateral Rectus

2. Superior Oblique

3. Medial Rectus

4. Inferior Rectus

The correct answer is: Medial Rectus

The most powerful extraocular muscle that turns the eye toward the nose is the medial rectus. This muscle is responsible for adduction, which is the movement of the eye inward towards the midline of the body. When the medial rectus contracts, it pulls the eye in a direction that aligns it towards the nose, facilitating gaze adjustments for both focusing on nearby objects and coordinating binocular vision. In contrast, the lateral rectus muscle moves the eye outward away from the midline, while the superior oblique and inferior rectus have different primary functions related to elevation, depression, and rotation of the eye. Therefore, the medial rectus is key for the adduction of the eye, making it the muscle that effectively turns the eye toward the nose.