Glaucoma is a disease that damages your eye’s optic nerve. It usually happens when fluid builds up in the front part of your eye. That extra fluid increases the pressure in your eye, damaging the optic nerve.
Primary open-angle glaucoma the most common type of glaucoma. It happens gradually, where the eye does not drain fluid as well as it should , As a result, eye pressure builds and starts to damage the optic nerve. This type of glaucoma is painless and causes no vision changes at first
The optic nerve is part of the central nervous system and carries visual information from the eye to the brain. This cranial nerve is made up of over one million nerve axons, which are nerve fibre extensions of the retinal ganglion cells. When the eye pressure is increased and/or other inciting factors exist, the optic nerve becomes damaged and the retinal ganglion cells undergo a slow process of cell death termed "apoptosis." The death of the retinal cells and degeneration of the nerve fibers results in permanent vision loss. Early diagnosis and treatment of glaucoma can help prevent blindness.