There are several types of glaucoma, including primary open-angle glaucoma, angle-closure glaucoma, congenital glaucoma and secondary glaucoma. Primary open-angle glaucoma develops slowly and painlessly when normal eye fluid known as aqueous humor doesn’t drain properly, causing pressure to build up within your eye. It accounts for 60 percent to 70 percent of all glaucoma cases.
About 10 percent of people with glaucoma have angle-closure glaucoma, which occurs suddenly and often causes dramatic symptoms. This type of glaucoma is a medical emergency and requires immediate treatment. A much smaller number of people have congenital glaucoma, which is present at birth, or secondary glaucoma, which results from trauma, chronic steroid use or disease. Still, the news about glaucoma is encouraging. When it’s detected and treated early, glaucoma need not cause blindness or even severe vision loss for most people.