Glaucoma is a chronic eye condition that affects the optic nerve, which is responsible for transmitting visual information from the eye to the brain. People with glaucoma have their optic nerve damaged when the intraocular pressure (IOP) within the eye increases and is not managed properly. This damage to the optic nerve can lead to vision loss and, if left untreated, may eventually result in blindness. Types of glaucoma There are two main types of glaucoma: Open-angle glaucoma and narrow-angle glaucoma. Open-angle glaucoma, also called primary open-angle glaucoma, is the most common form. It is characterized by a gradual increase in intraocular pressure (IOP) over time, which can damage the optic nerve. In this type of glaucoma, the drainage angle between the iris and cornea remains open, but the trabecular meshwork that controls the flow of fluid out of the eye is blocked or damaged. This fluid buildup can lead to increased intraocular pressure and damage to the optic nerve. Patients with open-angle glaucoma may have no symptoms in the early stages of the disease and gradually lose vision. On the other hand, angle-closure glaucoma, also known as closed-angle glaucoma or narrow-angle glaucoma, is less common but can be a medical emergency for patients. It occurs when the iris is pushed forward, and the drainage angle between the iris and cornea is blocked, resulting in a rapid increase in intraocular pressure. This sudden increase in intraocular pressure can cause severe eye pain, nausea, blurred vision, and seeing halos around lights. This type of glaucoma requires immediate medical attention to prevent permanent blindness. Angle-closure glaucoma is common in people of Asian descent and people with farsightedness. Risk factors There are several factors that increase the risk of developing glaucoma, including age, genetics, race, diabetes, and high blood pressure. However, some people can also develop the condition without these risk factors. This is why regular eye exams are essential for early detection of glaucoma. Common symptoms and diagnosis Symptoms of glaucoma vary depending on the type and stage of the disease. In open-angle glaucoma, patients may experience patchy blind spots in their peripheral vision, narrow vision, as well as difficulty adjusting to dim light. Meanwhile, angle-closure glaucoma can cause severe eye pain, headaches, nausea, blurred vision, and seeing halos around lights. Diagnosing glaucoma involves several tests, including measuring eye pressure, testing for optic nerve damage, and testing your visual field. Glaucoma is a serious condition that can lead to vision loss and blindness. While it is asymptomatic in its early stages, regular eye exams are necessary for early detection and management of the condition. If you are experiencing any symptoms or are at risk of developing glaucoma, it is important to consult with an eye care professional for proper prevention or diagnosis.