As one of the leading causes of blindness, glaucoma is characterized by a progressive degeneration of the optic nerve in the eye. If it isn’t detected early on, glaucoma can serve as the catalyst to a loss of nerve tissue, leading to gradual and irreversible vision loss, or full blindness.

Associated with increased fluid pressure in the eye, there are four distinct types of glaucoma: angle-closure, secondary, normal-tension and, the most common form, primary open-angle glaucoma. The latter occurs when the eye’s fluids stop draining properly, causing intense pressure on the optic nerve, which is responsible for transmitting all of the information the eye sees to the brain.

A complicated disease, glaucoma produces virtually no symptoms in its initial stages. In fact, most people who experience open-angle glaucoma typically show no signs because the first bit of vision loss comes from the side, or periphery, and the acuity and sharpness of vision is maintained until the disease has progressed.

Symptoms of glaucoma is likely include hazy and blurred vision; severe eye and head pain; nausea and vomiting; sudden sight loss; and the appearance of rainbow-coloured circles appearing around bright lights. When one of or more of these signs appear, it’s imperative to see an ophthalmologist immediately.