ABSTRACT
This chapter examines some of the conditions affecting the extraocular muscles. There are six extraocular muscles such as superior rectus, inferior rectus, medial rectus, lateral rectus, superior oblique, inferior oblique which move the eye in the directions of gaze. Muscular branches of the ophthalmic artery and vein are responsible for the supply and drainage of blood. Both eyes must move together in a coordinated manner. In order for this to occur, each extraocular muscle is paired with a muscle in the opposite eye. These pairs of muscles are known as synergistic or 'yoke' muscles. For example, to look to the right, the right eye looks outwards, i.e. abducts, while the left eye looks inwards, i.e. adducts. The right lateral rectus muscle abducts the right eye, while the left medial rectus muscle adducts the left eye. These two muscles work together to cause the eyes to look to the right.
