Eye Movements

The stabilization of eye movement is accomplished by six extraocular muscles that attach to each eyeball and perform their horizontal and vertical movements and rotation. These muscles are controlled by impulses from the cranial nerves that tell the muscles to contract or to relax. When certain muscles contract and others relax, the eye moves.

The six muscles and their function are listed here:

• Lateral rectus–moves the eye outward, away from the nose
• Medial rectus–moves the eye inward, toward the nose
• Superior rectus–moves the eye upward and slightly outward
• Inferior rectus–moves the eye downward and slightly inward
• Superior oblique–moves the eye inward and downward
• Inferior oblique–moves the eye outward and upward

There are five different types of eye movements:

• Saccades–looking from object A to object B
• Pursuit–smoothly following a moving object
• Convergence/divergence–both eyes turning inward/outward simultaneously
• Vestibular–eyes sensing and adjusting to head movement via connections with nerves in the inner ear
• Fixation maintenance–minute eye movements during fixation