part of part of contributes to morphology of anterior chamber of eyeball aqueous humor of eyeball http://upload.wikimedia.org/wikipedia/commons/1/1e/Schematic_diagram_of_the_human_eye_en.svg (...) we reach the inescapable conclusion that the last common ancestor of jawless and jawed vertebrates already possessed an eye that was comparable to that of extant lampreys and gnathostomes. Accordingly, a vertebrate camera-like eye must have been present by the time that lampreys and gnathostomes diverged, around 500 Mya (reference 1); Although the eye varies greatly in adaptative details among vertebrates, its basic structure is the same in all. The human eye is representative of the design typical for a tetrapod. (...) A watery aqueous humor fills the spaces in the eye in front of the lens (...) (reference 2).[well established][VHOG] EHDAA:10196 FMA says A+P chambers, and MA states A chamber. ZFA states A chamber and tha it is produced primarily by dorsal ciliary epithelial cells.To be investigated across taxa. ZFA:0005564 GAID:890 EHDAA2:0000139 The fluid produced by the ciliary process in the eye and occupying the anterior and posterior chambers. It provides nourishment for the lens and cornea and maintains the ocular pressure, and hence the optical integrity of the eyeball. [TFD][VHOG] aqueous humor MESH:D001082 FMA:58819 ENVO:02000024 EMAPA:18232 UBERON:0001796 A thick watery refractive medium that fills the space between the lens and the cornea[WP]. humor aquosus SCTID:280587006 aqueous humour VHOG:0000548 MA:0001236 Wikipedia:Aqueous_humor UMLS:C0003662 NCIT:C13190 ocular refractive media bodily fluid