American Board of Opticianry (ABO) Practice Test

Which muscle moves the eye inward?

1. The outer layer of the cornea

2. The type of corneal astigmatism with non-90-degree meridians

3. The muscle that moves the eye inward

4. The unit used to measure the displacement of a ray of light

The correct answer is: The muscle that moves the eye inward

The muscle responsible for moving the eye inward is specifically known as the medial rectus muscle. This muscle is one of the six extraocular muscles that control eye movement. When the medial rectus contracts, it pulls the eye towards the nose, allowing for convergence, which is necessary for binocular vision, especially when focusing on near objects. This muscular action is crucial for activities such as reading or any tasks that require close vision. Proper functioning of the medial rectus helps maintain proper alignment of the eyes and aids in depth perception. Understanding the role of this muscle is important for various aspects of opticianry and vision care, particularly in diagnosing and managing strabismus or other alignment issues that can affect vision.