Glaucoma causes vision loss through damage to the optic nerve, and according to the Glaucoma Research Foundation, about three million Americans suffer from the disease, but only about half know that they have it. Glaucoma is also the leading cause of preventable blindness in the United States.

But glaucoma can be prevented, and exercise is a great way to reduce your risk. Aerobic exercise lowers eye pressure, a major risk factor for glaucoma. Whether you have glaucoma or you’re trying to avoid it, regular aerobic exercise can help keep fluid flowing to and from the eye, thereby avoiding a buildup of pressure in the eye compartment.

For people with glaucoma, though, there are a few exercise precautions. Don't choose exercises that require you to stand on your head or shoulders or upside down; some yoga moves, scuba diving or bungee jumping may increase eye pressure, so instead, try walking, swimming or bicycling. In addition, after working out, make sure to rehydrate slowly. Drinking water or other fluids too quickly can also increase pressure in the eye compartment.

This January start a regular fitness routine in the name of your sight and in celebration of National Glaucoma Awareness Month. Another tip? Schedule a comprehensive eye exam that includes a test for glaucoma. Glaucoma often shows up without any symptoms, so you won't know you have it until you're tested.

Sources:  The Glaucoma Foundation, www.glaucoma-foundation.org; Glaucoma Research Foundation, www.glaucoma.org.