Certified Paraoptometric (CPO) Practice Exam 2025

The clear, watery fluid produced by the ciliary body is known as?

1. Vitreous humor

2. Aqueous humor

3. Corneal fluid

4. Retinal fluid

The correct answer is: Aqueous humor

The correct term for the clear, watery fluid produced by the ciliary body is aqueous humor. This fluid plays a crucial role in maintaining intraocular pressure, providing nutrients to the avascular structures of the eye, and facilitating the removal of metabolic wastes. It fills the anterior and posterior chambers of the eye, situated between the cornea and the lens, and is essential for the proper function of the eye. Vitreous humor, for instance, is a gel-like substance that fills the larger space in the posterior segment of the eye, not produced by the ciliary body. Corneal fluid is not an anatomical term typically used in ophthalmology to describe any specific eye fluid, and retinal fluid generally refers to fluids related to the retina, which are not secreted by the ciliary body. Therefore, the precise identification of aqueous humor as the fluid in question underlines its specific function and origin within the eye.