Sagittal section of dog eye

 

Sagittal section of dog eye. 1, tapetum lucidum; 2, nontapetal nigrum; 3, lens; 4, ciliary body; 5, posterior chamber; 6, anterior chamber; 7, iris; 8, cornea; 9, superior eyelid/palpebra; 10, palpebral conjunctiva; 11, bulbar conjunctiva; 12, fornix; 13, sclera; 14, choroid; 15, retina; 16, superior retinal vein; 17, optic disk/disc; 18, optic nerve; 19, dura and arachnoid mater; 20, inferior medial retinal vein; 21, third eyelid. (from Guide to Dissection of the Dog)