There are four different types of glaucoma: Open-angle glaucoma: The most common form of the disease. Pressure from the trabecular meshwork in your eye is partially blocked, which damages your optic nerve. This type happens slowly and it’s hard for you to notice changes in your vision Angle-closure glaucoma (also called closed-angle glaucoma): If the iris in your eye bulges forward, it can prohibit fluid from circulating in your eye, causing pressure. It can occur suddenly (a medical emergency) or gradually Normal-tension glaucoma: This type happens when your eye pressure is healthy, but your optic nerve still somehow becomes damaged Pigmentary glaucoma: Pigment granules from your iris build up in your eye’s drainage channels, making it hard for fluid to leave your eye