It is very important that anyone at high risk for glaucoma be screened for the disease. This group includes African-Americans, those with a family history of glaucoma, those with a history of increased eye pressure or existing visual field defects, as well as users of oral contraceptives. Research indicates that women who have taken oral contraceptives for three or more years are twice as likely to suffer from glaucoma. The study analyzed data from the National Health and Nutrition Examination Survey (NHANES), which included 3,406 female participants aged 40 years or older from across the United States. While it does not pinpoint a causative factor, it does suggest that all women at risk undergo glaucoma screening. Glaucoma cannot be prevented, but the earlier it is diagnosed, the greater the likelihood that it can be slowed down or even stopped with medication before vision is significantly impacted. Most people do not even know they have glaucoma until they suffer irreversible vision loss (which is why screenings are so important).