What is the function of the aqueous humor?

• A. Transmits light to retina
• B. Maintains intraocular pressure
• C. Nourishes the cornea exclusively
• D. Controls accommodation

Answer: (B)

The essential role of the aqueous humor is to keep the eye’s shape by maintaining intraocular pressure. It’s a clear fluid produced by the ciliary body, circulating from the posterior chamber through the pupil into the anterior chamber, and exiting mainly via the trabecular meshwork and Schlemm’s canal. This continuous production and drainage balance preserves the globe’s pressure, which is crucial for proper focusing and optical stability. While the aqueous humor does provide nutrients to avascular tissues like the cornea and lens, its primary functional emphasis in this context is upholding intraocular pressure. Light transmission and accommodation involve other structures: light travels through the cornea and lens, and accommodation is controlled by the ciliary muscle changing the lens shape.