First, it was difficult to find good early-stage sections because of tilting of the sectional planes. Likewise, specimens from near-term fetuses are difficult to obtain, not only in Japan but elsewhere. Rather than using fetal specimens, we are now preparing a further study using a larger number of adult cadavers. Second, sections of specimens taken from elderly adults did not include all of the bony elements at and around the orbital apex, and only parts of the sphenoid. Therefore, the topographical anatomy at and along the superior orbital fissure might not have been well demonstrated. For further study, it would be important to obtain larger tissue blocks from intact cadaver orbits. Third, although it might be out of focus, the present study showed individual variations in several morphologies: (1) a site of origin of a common tendon of three recti, (2) a site of origin of the SR, and (3) an additional slip of the MR; thus, we wish to find the individual variation between more specimens of almost the same age.