How many muscles are there in an eye?
There are six muscles outside the eyeball and one muscle inside the eyeball. What do the external (outside) muscles of the eye do? What are they used for? The eyeball is kept in the desired position, and turned from place to place, by the use of six muscles. These muscles are identically placed in both eyes to permit synchronous movement. There are essentially four muscles, termed rectus (Latin for straight) muscles, which by their actions move the eyes up or down (the superior and inferior rectus), outwards towards the temple or inwards towards the nose (lateral and medial rectus). There are also two oblique muscles which move the eye in oblique directions called the superior and inferior oblique muscle. The movements of the two eyeballs in the cardinal directions require the muscles of both eyes working together. Thus the medial rectus (which turns the eye in) of one must work together with the lateral rectus (which turns the eye out) of the other to permit the eyes to move simultane
