After having been the subject of several studies during the first half of the 20th century, the anatomical and morphological measurements of the ocular rectus muscles have recently been reinvestigated (e.g. L. Apt). At the Anatomy Institute in Geneva, similar measurements were performed on 25 human orbits as well as the depth of the subtenon space. The results show a large variation from one individual to another, although the "Tillaux spiral" was always respected. We have also shown that the ratio of the arc between each pair of opposed rectus muscles is a constant equal to 1 (0.997 +/- SD = 0.031). The subtenon space was defined morphometrically and confirmed histologically. All these measurements are important for practical aspects involved in the surgery of strabismus.