Monastral Fast Blue, BVS paste is mixed with water (1 part to 3 parts, respectively) and injd. under pressure into the central retinal artery in the cut optic nerve of the enucleated eye. The cannula is inserted into the artery under binocular microscopic view. The eye is fixed in 5% formol for a short time before injn. to harden the tissues sufficiently to allow insertion of cannula. After injn. there is a further period of fixation, and then the eye is cut in coronal section through the equator, the vitreous is removed, and the injd. retinal vascular system studied with the slit-lamp and microscope.