The extraocular muscles function to move the eyes together. There are four recti muscles, two oblique muscles which make the movements of the eye possible. In this article, we will not only cover the muscles that move the eye, but also the accessory muscles of the eye involved in eyelid action.
There are six muscles in each eye which function to move the eye around in the orbit in various directions. These are:
The four recti are arranged at the top, bottom and sides of each eye as shown in the diagram below:
Diagram showing the recti muscles of the eye.
The four recti all converge at the back of the orbit on a common tendinous ring (also called the annulus of Zinn), as shown here:
Diagram showing a lateral view of the eye showing the recti muscles.
The oblique muscles have a different origin, which will be discussed below.
The superior oblique muscle originates on the lesser wing of the sphenoid bone, passes through a pulley called the trochlea and then changes its angle to attach onto the superolateral aspect of the eyeball, as shown in the diagram below.