Anterior segment of eyeball

The anterior segment is the front third of the eye that includes the structures in front of the vitreous humour: thecornea, iris, ciliary body, and lens.

Within the anterior segment are two fluid-filled spaces:

• the anterior chamber between the posterior surface of the cornea (i.e. the corneal endothelium) and the iris.
• the posterior chamber between the iris and the front face of the vitreous.

Aqueous humor fills these spaces within the anterior segment and provides nutrients to the surrounding structures.