Glaucoma is called the “sneak thief of sight” because it can result in the permanent loss of peripheral vision without pain or symptoms until it is too late.

Glaucoma is an increase of pressure within the eye that eventually damages the optic nerve at the optic nerve head. Aqueous humor produced in the ciliary body travels into the anterior chamber through the pupil. If the aqueous cannot drain because the draining system, called the trabecular meshwork, is clogged or closed due to a narrowing, the aqueous is trapped.

Production of aqueous continues but there is nowhere for it to drain so it builds up and creates pressure that pushes backwards on the internal structures of the eye.

Glaucoma damages the nerve fibers, blood vessels and the optic nerve. The result is a loss of the peripheral field of view. (From the companion eBook for “SIGHT, The Story of Vision,” free download at

Cheryl Murphy, O.D., teaches patients that, “Glaucoma is a condition which can slowly rob someone of their vision, and they may not even notice until significant damage has already been done to their eyes. This is because it is usually painless and virtually symptomless until it is already too late. Glaucoma is one more reason why yearly eye exams are so important. Getting eye pressures checked and having the eye doctor examine the physical appearance of a person’s optic nerves can help screen for early warning signs of glaucoma, which a person could have and not even know it; early diagnosis and treatment can make a difference in its prognosis.”