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Medical Author:

Andrew A. Dahl, MD, FACS

Andrew A. Dahl, MD, FACS

Andrew A. Dahl, MD, is a board-certified ophthalmologist. Dr. Dahl's educational background includes a BA with Honors and Distinction from Wesleyan University, Middletown, CT, and an MD from Cornell University, where he was selected for Alpha Omega Alpha, the national medical honor society. He had an internal medical internship at the New York Hospital/Cornell Medical Center.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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High pressure inside of the eye is caused by an imbalance in the production and drainage of the fluid in the front of the eye (aqueous humor). The channels that normally drain the fluid from inside the eye consequently do not function properly or are blocked. Since more fluid is continually being produced within the eye but cannot be drained because of the improperly functioning or blocked drainage channels, the result is an increased amount of fluid inside the eye itself, thus raising the pressure.

Another way to think of high pressure inside the eye is to imagine a water balloon. The more water that is put into the balloon, the higher the pressure inside the balloon. The same situation exists with too much fluid inside the eye, which unlike a balloon, is not distensible. The more fluid, the higher the pressure within the fixed space of the eye. Also, just like a water balloon can burst if too much water is put into it, the optic nerve in the eye can be damaged by pressure that is too high.

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