The extraocular muscles are the six muscles that turn each eye, all inside the eye socket: four recti that run forward from a tendon ring at the back of the socket to the eyeball, and two obliques. The oculomotor nerve works four of them; the trochlear and abducens nerves work one each. [1][2]
The 3D brain needs JavaScript. The text below still says where the extraocular muscles are and what they do.
Takes part in: eye movements — see every part of each lit together.
Where it is
The four recti (superior, inferior, medial and lateral) start from the common tendinous ring (annulus of Zinn) at the back of the orbit, around the optic canal, and run forward along the four sides of the eyeball to attach to the sclera in front of its equator. [1][5]
The superior oblique starts above the ring, runs forward along the upper inner wall of the orbit, passes through a small cartilage pulley, the trochlea, and turns back to attach to the top of the eyeball behind its equator. [1][2]
The inferior oblique is the only one that starts at the front of the orbit, from its floor near the nose, and runs back under the eyeball to its outer side. [1][2]
What it does
Medial rectus: turns the eye in toward the nose. Lateral rectus: turns it out. Superior rectus: turns it up (and slightly in, rolling its top inward). Inferior rectus: turns it down (and slightly in, rolling its top outward). [1]
Superior oblique: rolls the top of the eye inward and turns it down and out, most strongly when the eye already looks toward the nose. Inferior oblique: rolls it outward and turns it up and out. [1]
Nerves: the abducens nerve (VI) works the lateral rectus, the trochlear nerve (IV) the superior oblique, and the oculomotor nerve (III) the other four. [1][6]
Every eye movement, from a quick saccade to smooth pursuit, is these muscles pulling in pairs; the brainstem gaze centres drive the two eyes together so both point at the same place. [7][1]
A seventh muscle in the orbit, the levator palpebrae superioris, is often counted with them, but it lifts the upper eyelid rather than the eye; it is not drawn on this site’s model. [1][3]
Connections
From: the oculomotor, trochlear and abducens nerves, which bring the commands from their nuclei in the midbrain and pons. To: the sclera of the eyeball, where each muscle’s tendon attaches. [1][6]
Other names
Extrinsic eye muscles, extraocular muscles; the recti (rectus muscles) and the obliques. Musculi bulbi (Latin). [1]
Size
On this model the six muscles of the left eye fit in a box about 47 mm front to back, 31 mm top to bottom and 32 mm side to side (the box they fit in, not their volume); the right set is its mirror image. [3]
Facts describe anatomy and normal function only. The 3D model is the adult male BodyParts3D brain (credits and licence); real brains vary in size and shape, so its measurements describe one model, not anyone’s brain.