Glaucoma is a leading cause of vision loss and blindness. The damage to the optic nerve that carries images to the brain generally occurs due to a build-up of pressure in the eye. The National Eye Institute recommends regular eye exams by an optometrist or ophthalmologist to detect glaucoma early and prevent vision loss. As some types of glaucoma do not have symptoms in the early stages, it is important to have regular eye exams.
The optic nerve is comprised of several nerve fibers that carry images from the eye to the brain. When glaucoma develops, it causes gradual damage to the optic nerve, causing symptoms that affect the vision. The Eye Institute lists symptoms of changes to vision such as blind spots, blurry vision and tunnel vision. Blank spots may also begin to appear in line of sight. At first, the blank spots may be too small too notice, but may become more obvious as they become larger. Tunnel vision is an early specific symptom of some types of glaucoma and occurs as a gradual loss of peripheral vision that affects both eyes simultaneously. If glaucoma is left untreated, vision worsens as all the optic nerve fibers are completely damaged, leading to blindness.
Changes to vision include symptoms related to light. Eye Care America notes that people with some types of glaucoma may see rainbow-colored halos around lights and other bright objects.
The University of Maryland Medical Center says that some types of glaucoma can begin and worsen quickly and cause pain. Pain symptoms include severe eye and headache pain. In some cases and types of glaucoma, the pain symptoms may be accompanied by nausea and vomiting. Closed-angle glaucoma is one type that progresses very rapidly causing pressure build-up and pain. It occurs when the iris of the eye blocks the drainage channels completely causing sudden and acute symptoms.