The presented study was carried out on the fetal specimens of the eye-ball, together with the retrobulbar part of the optic nerve which were obtained from 15 human fetuses aged 16-20 weeks of the intrauterine life. The vascular casts were prepared by injection of low-viscosity resin Mercox which afterwards were analyzed in a scanning electron microscope (SEM). The technique employed allowed the authors to describe both the vascular pattern of the optic nerve as well as the network of arterial vessels which formed the Zinn and Haller's circle. The own original findings are compared with results obtained by other authors on the vasculature of the optic nerve in mammals and humans in different periods of the life.