State the Uni-ocular Movements
In each eye, for every movement there is an agonist, antagonist, and a synergist. An agonist is the main muscle that is active in carrying out the movement. A synergist is another muscle in the same eye that along with the agonist produces an effect. An antagonist is a muscle in the same eye that acts in the opposite direction to the movement. Adduction is the inward movement along the vertical axis. Abduction is an outward movement along the vertical axis. Elevation is an upward movement along the horizontal axis and depression is a downward movement along the horizontal axis. Intortion (Incycloduction) is a rotatory movement along the antero-posterior axis in which the superior pole of the cornea moves medially. Extortion (Excycloduction) is a rotatory movement along the antero-posterior axis in which the superior pole of the cornea moves laterally.