Final answer:
The posterior chamber of the eye is filled with the vitreous humor, a viscous fluid that helps maintain the eye's shape and optical properties.
Step-by-step explanation:
The posterior chamber of the eye is filled with a gelatinous substance known as the vitreous humor. This is a viscous fluid that fills the space behind the lens and extends to the posterior side of the interior eyeball, up to where the retina is located. Unlike the anterior chamber, which contains the aqueous humor, a watery fluid, the posterior chamber's vitreous humor has a jelly-like consistency that helps maintain the eye's shape and optical properties.