At first it causes no vision problems, but all the while it is robbing you of sight that you will never get back. Think of your eye as a fountain, with fluid constantly circulating to nourish the tissues and maintain the eyeball's round shape.
Chronic glaucoma progresses very slowly.
Often, the first sign of trouble is reduced side vision. Other indicators may include blurred vision, seeing colored halos around lights, adjustment problems on entering a dark room, and repeated difficulties that new eyeglass prescriptions do not help. Acute glaucoma comes on suddenly, causing severe eye pain and nausea and vomiting along with these vision problems. Yes, and the earlier the better. These medications must be taken faithfully every day for life.