The signs or symptoms of glaucoma can vary depending on the type Primary open-angle glaucoma often develops slowly and painlessly, with no early warning signs. It can gradually destroy your vision without you knowing it. The first indication that you have glaucoma may occur after you’ve already lost some vision. Acute-angle closure glaucoma results from a sudden blockage of drainage channels in your eye, causing a rapid buildup of pressure. In this form of the disease you will have blurred vision, the appearance of halos or colored rings around lights, and pain and redness in the eye.