A study of adults 40 and older suggests high cholesterol levels are associated with increased risk for the most common form of glaucoma, while longer use of a cholesterol-lowering statin, compared with never using, was associated with lower risk. Data for this observational study came from more than 136,000 adults who participated in three national study groups and provided information on their statin use and cholesterol levels over 15 years. There were 886 new cases of primary open-angle glaucoma (POAG) identified among the adults. The association between longer statin use for five or more years and lower risk of POAG was stronger among those 65 and older. The study is limited by self-reported statin use and cholesterol levels, and the results also may not generalize to other groups because study participants were mostly white health care professionals. These results need to be confirmed in other studies but they are of interest given the widespread use of statins in older persons at risk for this type of glaucoma.