From the Guidelines
To look up and right, the superior rectus and lateral rectus muscles contract in both eyes, with the superior rectus primarily responsible for the upward movement and the lateral rectus handling the rightward movement, as supported by the most recent study on adult strabismus preferred practice pattern 1. The movement of the eyes to look up and right involves a coordinated action of multiple extraocular muscles.
- The superior rectus muscle is primarily responsible for the upward movement (elevation) of the eyes.
- The lateral rectus muscle is responsible for the outward movement (abduction) of the eyes.
- In the right eye, the lateral rectus contracts strongly to pull the eye outward (temporally).
- In the left eye, the medial rectus contracts to move that eye inward (nasally), which is necessary for conjugate eye movement. Additionally, the inferior oblique muscles in both eyes assist with the upward movement component, particularly in the adducted position of the eye. This coordinated muscle action is controlled by cranial nerves III (oculomotor) and VI (abducens), with the oculomotor nerve innervating the superior rectus and inferior oblique muscles, and the abducens nerve controlling the lateral rectus, as described in the study on adult strabismus preferred practice pattern 1. The precise coordination between multiple extraocular muscles allows for smooth, conjugate eye movements that maintain single binocular vision as you look in different directions, which is crucial for preventing diplopia and maintaining quality of life, as highlighted in the study on sagging eye syndrome 1.
From the Research
Extraocular Muscles Involved in Eye Movement
To bring both eyes to look up and right, the following muscles contract:
- The superior rectus muscle in each eye, which is responsible for elevation (looking up) [@\5@]
- The lateral rectus muscle in the right eye, which is responsible for abduction (looking right) [@\4@, @\5@]
- The inferior oblique muscle in each eye, which assists in elevation and also rotates the eye outward (looking right) [@\3@, @\5@]
Muscle Contractility and Eye Movement
Studies have shown that the contractility of extraocular muscles can be measured using magnetic resonance imaging (MRI) [@\3@, @\4@]. The superior rectus muscle and inferior oblique muscle contract to elevate the eye, while the lateral rectus muscle contracts to abduct the eye [@\3@, @\4@, @\5@].
Coordination of Eye Movement
The coordination of eye movement involves the contraction and relaxation of multiple extraocular muscles [@\1@, @\2@]. The superior rectus muscle, lateral rectus muscle, and inferior oblique muscle work together to bring both eyes to look up and right [@\3@, @\4@, @\5@].