The glaucomas are a group of conditions with varying causes. The common feature is that they all cause a particular pattern of damage to the optic nerve (that connects the back of the eye to the vision parts of the brain), which usually damages the peripheral or side vision before the central vision is involved. Because this often happens slowly, and we concentrate so much on our central vision, most patients with glaucoma are unaware of the damage occurring to their sight until it is very advanced. Because this damage cannot be reversed, early detection of glaucoma is critical. This can only occur with regular eye assessments, which is one reason why it is recommended that anyone over the age of 45 should have a regular assessment by an optometrist. Once glaucoma has been detected, further damage can be minimised or prevented with treatment.
Many people think of glaucoma as meaning a high pressure in the eye (which is a fluid filled ball, and therefore has a certain level of pressure within it). While the pressure in the eye is a major risk factor, many patients with glaucoma have a pressure that is within the normal population range. Conversely, many patients with pressure above the normal range do not have glaucoma. An ophthalmologist or optometrist can assess your eyes to decide if there is any likelihood that you have glaucoma.