Glaucoma is the root cause of about 10 percent of total blindness in the United States, and many of the people affected are seniors (those over the age of 65). Additionally, the American Academy of Family Physicians notes that about 75 percent of those who are legally blind because of glaucoma are seniors. The overall number of Americans who have glaucoma is estimated to be around three million, but as the Glaucoma Research Foundation points out, it’s believed that half of people with glaucoma haven’t been diagnosed yet. Read more here