Musculus rectus lateralis
Abducts the eye (turns it outward/temporally). The only extraocular muscle innervated by the abducens nerve (CN VI).
Origin: Common tendinous ring around the optic foramen
Insertion: Lateral sclera of the eyeball
Action: Abducts the eyeball (rotates temporally)
Innervation: Abducens nerve (CN VI)
Abducens nerve damage causes the eye to deviate medially (inward) because the lateral rectus cannot oppose the medial rectus pull. May accompany guttural pouch disease or polyneuritis.
Abducens nerve damage causes the eye to deviate medially (inward) because the lateral rectus cannot oppose the medial rectus pull. May accompany guttural pouch disease or polyneuritis. Signs include: Eye deviated medially (cross-eyed); inability to look laterally; may be accompanied by retractor bulbi weakness and third eyelid prolapse (since CN VI also innervates the retractor bulbi).
See the Lateral Rectus on our interactive 3D horse model. Open 3D Model