Vascular casts of the human lamina cribrosa region were studied in three autopsy specimens utilizing scanning electron microscopy (S.E.M.) in own modified technique. The lamina cribrosa is supplied from two major sources, the short posterior ciliary artery within the sclera and the distal optic nerve sheath pial vasculature. Recurrent choroidal arteries supplied a small number of centripetal branches to the lamina cribrosa. The central retinal artery did not give off centrifugal branches as it coursed through the lamina. The findings in these three human cases in three-dimensional visualization support other recent studies using serial histologic sectioning techniques. The photomicrographs are presented as a first successful images in S.E.M. for additional appreciation of the topographic morphology of radial arterioles.