Many of our 19th-century beliefs about the extraocular muscles (EOMs) are wrong:

• EOMs are homogeneous structures that rotate the globe.
• EOMs follow straight paths from orbital apex to scleral insertion.
• Everyone has the same arrangement of EOMs.
• Abnormalities of EOMs are limited to underaction (paralysis or paresis), overaction, innervational miswiring, or stiffness.
• All important pathophysiology of EOMs can be diagnosed by clinical motility examination.
• Orbital connective tissues and EOM sleeves are not clinically very important.

Revelations from 21st-century science:

• Surface coil MRI of living human orbits has near microscopic resolution.
• Digital imaging of immuno- and histochemically stained whole human orbits permits 3D reconstruction and correlation with in vivo MRI.
• Classical physiologic data was equivocal and can be more satisfactorily reinterpreted in light of recent anatomical findings.