Intraocular pressure, or eye pressure, represents the fluid pressure within the eye. This internal pressure is a fundamental component of ocular health, maintaining the eye’s physical structure and proper function. Keeping eye pressure within a healthy range is important for preserving vision and safeguarding the eye’s delicate internal structures.
What is Eye Pressure?
Eye pressure, or intraocular pressure (IOP), is the force exerted by the fluid inside your eye. This fluid, known as aqueous humor, is a clear, watery substance that fills the front part of the eye. The aqueous humor is continuously produced by specialized tissue called the ciliary epithelium, located behind the iris.
The aqueous humor flows through the pupil into the front chamber of the eye, then drains out through the trabecular meshwork. A balanced production and drainage of this fluid maintains a stable IOP, measured in millimeters of mercury (mmHg).
Typical Eye Pressure Ranges and Age
The normal range for eye pressure is typically between 10 mmHg and 21 mmHg. While 15.5 mmHg is considered an average value, eye pressure can fluctuate throughout the day and varies among individuals.
There is no specific “normal range” for each decade of life; a general healthy range applies across adult ages. Eye pressure can slightly increase with age for some individuals. This is partly because the eye’s natural drainage system may become less efficient over time due to age-related changes, potentially leading to a gradual increase in IOP. Age is considered a risk factor for certain eye conditions linked to elevated IOP.
The Importance of Healthy Eye Pressure
Maintaining healthy eye pressure protects the optic nerve and preserves vision. The optic nerve, which transmits visual information from the eye to the brain, is susceptible to damage from sustained high pressure. Elevated eye pressure can compress and harm its delicate nerve fibers.
This damage can lead to glaucoma, a group of eye conditions resulting in irreversible vision loss. Glaucoma is often called the “silent thief of sight” because it typically progresses without noticeable symptoms in its early stages. While less common, very low eye pressure can also indicate underlying issues, such as fluid leakage or a problem with the eyeball’s structure.
Monitoring and Managing Eye Pressure
Regular eye examinations are important for monitoring eye pressure, especially as individuals age or if they have risk factors like a family history of eye conditions. Eye pressure is measured using a tonometer during a comprehensive eye exam. This procedure, known as tonometry, involves gently assessing the cornea’s resistance to determine internal pressure.
Various tonometry methods exist, including Goldmann applanation tonometry and non-contact or “air-puff” tonometry. If eye pressure is outside the healthy range, or if other risk factors are present, an eye care professional can advise on the appropriate course of action. Management may include lifestyle adjustments, such as a healthy diet and regular exercise, and medical interventions to regulate IOP.