The posterior chamber of the eye is smaller than the anterior chamber. It extends from the iris to the vitreous body - in it lies the lens. The aqueous humor - which fills both the posterior and anterior chambers of the eye - is formed in the ciliary body and serves to nourish the lens and cornea. It also stabilizes intraocular pressure and thus the shape of the eye.

The transparent aqueous humor consists of 98 percent water, in which nutrients and oxygen are dissolved. Incidentally, the aqueous humor - even though it is transparent instead of red - resembles blood serum. However, it does not contain proteins.