Summary1. The nutrition of the peripapillary region of the retina depends in part on the blood vessels of the optic nerve.2. There is an axial nutrition system in the optic nerve.3. The central retinal artery is not responsible for the nutrition of the optic nerve.4. The chiasma is irrigated by II arteries and by a network of anastomotic arterioles (prcchiasmatic, arteriolar arcade).5.The optical tract has a double vascularisation system (the anterior choroidal artery and the posterior communicating artery). This can explain the frequent absence of homonyme hemianopsia after ligation of the anterior choroidal artery.