Drawing of a cross section of an eye showing no diabetes damage with the retina, blood vessels on the retina, the optic nerve, the vitreous, and the lens labeled. Drawing of a cross section of an eye showing some diabetes damage with the retina, blood vessels on the retina, the optic nerve, the vitreous, and the lens labeled. Drawing of a cross section of an eye showing a lot of diabetes damage with the retina, blood vessels on the retina, the optic nerve, new blood vessels, the vitreous, and the lens labeled.