Glaucoma is mainly caused by raised eye pressure. It is the gradual loss of nerve cells in the eye, resulting in a slow loss of vision until eventually the eye is blind. To date, dead nerve cells cannot be replaced. Loss of vision is therefore, as yet, permanent. It cannot be reversed by treatment.

People with glaucoma rarely notice any symptoms until the disease is very advanced. This is firstly because you feel no pain. Moreover, you can read and perform most tasks for many years, because the visual loss is not a blurred vision. What is affected first is side vision or the visual field, which is the area an eye can see when it looks straight ahead. And what makes the disease actually treacherous is that the blind areas do not manifest themselves by black clouds. That is because these areas are being filled-in with the colors and patterns of the surrounds. Your brain is able to do that by use of visual information received from adjacent, still functional, nerve cells in the eye. Only after loss of a very substantial part of the eye’s nerve cells, the brain is not able anymore to compose a plausible image. Thus you are unable to realize you have the disease, up to the point where your visual field is narrowed dramatically and permanently. In the last stage of the disease central vision is also lost and the eye is blind. Both eyes are commonly affected, and one eye more so than the other.

Although damage from glaucoma cannot be reversed, treatment can prevent nerve cell death and visual loss, if initiated in time. Early detection through regular eye exams of people who are at risk for glaucoma, is the key to protect them from visual loss, or to preserve their remaining vision.