The arterial vasculature of the eye in mule depends mainly on the branches of the A. ophthalmica externa, however, the internal ophthal mic artery shares also in the vasculature of the retina and eye ball. A retinal branch, in addition to the central artery of the retina was found to share in the nutrition of the nervous tunic of the eye ball. A great similarity was found between mule and other equines in the pattern of branching and distribution of the ophthalmic arteries.