Fig. 3. Location of average muscle insertions with respect to the corneal limbus, based on measurements in 100 autopsy eyes. Dimensions are in millimeters. IR, superior rectus; MR, medial rectus; IR, inferior rectus; LR, lateral rectus. (Apt L: An anatomical reevaluation of rectus muscle insertions. Tr Am Ophth Soc 78:365, 1980.)