January is Nation Glaucoma Awareness Month. Currently, 2.7 million people in the United States over age 40 have glaucoma. Glaucoma is a group of eye diseases that slowly steal sight without warning. There are two main types of glaucoma: primary open-angle glaucoma and angle –closure glaucoma. Glaucoma is marked by checking the intraocular pressure or pressure in the eye. Glaucoma is the second leading cause of blindness in the world, according to the World Health Organization. There are virtually no symptoms. Vision loss begins with side vision. The best way to prevent losing sight due to glaucoma is to get a comprehensive eye examination. Early detection is very important towards treatment of the eyes.