Aqueous humor

aqueous humor

Aqueous humor is the clear, watery fluid that fills the front part of the eye between the cornea and the lens. It is produced by a structure called the ciliary body and flows through the pupil into the front chamber before draining out through specialized drainage pathways. This fluid brings oxygen and nutrients to parts of the eye that don’t have blood vessels, such as the cornea and the lens, and it helps carry away waste products. Aqueous humor also helps maintain the eye’s shape and contributes to intraocular pressure, the internal pressure that keeps the eyeball properly formed. If production and drainage are balanced, eye pressure stays in a healthy range; if drainage is blocked or production is too high, pressure can rise and damage the optic nerve, which is what happens in glaucoma. The fluid is mostly water but also contains salts, glucose, and small proteins that support cell health and keep the interior of the eye chemically stable. Because it is constantly produced and drained, doctors measure its flow and pressure during eye exams to check for problems. Treatments for some eye conditions work by reducing how much of the fluid is made or by improving how easily it leaves the eye, which lowers harmful pressure. The composition and flow can change with time of day, medications, and other health factors, so those are taken into account when evaluating vision health. In short, aqueous humor is a small but vital component that nourishes, supports, and protects the eye, and keeping its balance is essential for good sight.