Glaucoma develops when excess pressure within the eye begins to damage the optic nerve. This nerve is vital to your sense of sight, transmitting visual data from the eye to the brain. Without a properly functioning optic nerve, blindness results.
By the time you notice glaucoma-related changes to your vision, it is usually too late. One type of glaucoma does announce its presence with a few early symptoms, however. Patients with “angle-closure” glaucoma report blurry vision, rainbow halos around bright lights, eye pain and often nausea.