Natural factors that can cause eye pressure include an overproduction of aqueous, eye injuries, slow aqueous drainage and medications containing steroids. A person's ethnicity, age and family medical history are also considered risk factors for conditions associated with eye pressure.
High eye pressure is called ocular hypertension. Although the condition can be benign, it can also lead to glaucoma or vision loss. Ocular hypertension can be diagnosed by a physician through an eye pressure reading. Eye pressure is measured in millimeters of mercury, with a level of 21 or more typically indicating ocular hypertension.
Behind the iris is the ciliary body, which creates the fluid aqueous. This fluid fills the area between the iris and cornea, and drains from that area through the trabecular meshwork. A higher than normal amount of aqueous, caused by either too much production from the ciliary body or slower than normal drainage, causes high eye pressure. Eye injuries can cause either issue, in some cases even if the injury occurred years before the aqueous problem.
Eye pressure can occur in some people due to specific medications. Medications which tend to cause this are those with steroids, including steroid eye drops used after corrective eye surgery. Eye pressure problems are more common in people older than 40 and in African Americans.