Some 3 million Americans have glaucoma. Unfortunately, half of them are unaware they have this potentially blinding disease because they have no symptoms. “Too many people believe they can tell if they’re developing glaucoma,” says Dr. Gregory K. Harmon, Chairman of The Glaucoma Foundation and author of What Your Doctor May Not Tell You About Glaucoma. “That’s one dangerous myth among numerous others,” he adds. Here are some of the myths Dr. Harmon explodes in his book.

Myth 1: Your vision will deteriorate or blur if you are developing the disease.
Most forms of glaucoma have no symptoms or cause and no change in vision until late in the course of the disease. Once vision has been lost due to glaucoma, permanent damage has already been done to the optic nerve, and sight cannot be regained. This is why early detection and treatment before vision loss occurs is so vital.

Myth 2: Only old people get glaucoma.
Though frequency increases with age, glaucoma can strike at any time in a person's life. Approximately one in 10,000 babies is born with glaucoma, and children between the ages of 4 and 10 may develop a form of the disease called late congenital glaucoma. For those affected between ages 10 and 35, the most common causes are hereditary disorders.

Myth 3: Glaucoma is always inherited.
Family history is a strong risk factor for glaucoma, but an absence of family history does not mean a person is risk-free. If there is a family history of glaucoma, everyone in the family -- from children on up -- should be sure to get regular eye exams.

Myth 4: Ethnicity has nothing to do with glaucoma risk.
African Americans and Asians are at particularly high risk for developing glaucoma. Researchers have also recently discovered that glaucoma is far more common among U.S. Hispanics than originally thought. African Americans, who are 6 times as likely to suffer from glaucoma as Caucasian Americans, develop glaucoma 10 years earlier and are 14 to 17 times more likely to go blind than their Caucasian counterparts.

Myth 5: All people with glaucoma have elevated intraocular pressure (IOP).
Elevated IOP is a risk factor for glaucoma and is not the disease itself. There are more than 40 different types of glaucoma, and not all of them are associated with elevated IOP. Glaucoma specialists believe that some forms of glaucoma are strongly related to vascular changes and impaired “nutrition” (poor blood flow) to the optic nerve. The common thread among all glaucoma is damage to the optic nerve rather than elevated IOP.

Myth 6: If you don't have high blood pressure, you cannot have high eye pressure.
Blood pressure and eye pressure vary independently. Controlling blood pressure does not mean IOP is controlled. However, high blood pressure is often - but not always - associated with elevated intraocular pressure. Interestingly, low blood pressure is strongly associated with some forms of glaucoma, such as normal-tension glaucoma.

Myth 7: You can test your own peripheral vision to see if you have glaucoma.
Most forms of glaucoma affect peripheral (to-the-side) vision rather than central (straight-ahead) vision. It is impossible to evaluate the state of your vision without a true visual field test conducted in the eye doctor's office. Furthermore, visual field testing is just one of the three vital diagnostic tests for glaucoma. It is also important for the doctor to look at the optic nerve head (disc) and to measure the IOP.

Myth 8: Glaucoma always leads to blindness.
This is one of the most dangerous myths of all. Some 90% of all glaucoma-related blindness could have been prevented with proper treatment. In fact, glaucoma is the leading cause of preventable blindness. But you can’t get treatment unless you know you have a problem!

January is Glaucoma Awareness Month. Whether or not you know you have glaucoma, it is crucial to talk with your doctor about diagnosis and treatment plans. Early diagnosis and treatment are the keys to controlling this “sneak thief of sight.” Call today and make an appointment to get your eyes examined. Make sure to encourage your friends and family to do the same.