Glaucoma can be caused by increased pressure of the fluid in the eye. The inside of the eye contains fluid that is constantly flowing into and being drained out of the eye.
If the drainage mechanism in an area called Trabecular meshwork gets blocked, fluid starts accumulating in the eye, exerting pressure inside the eye.
This extra fluid that builds up in the eye presses against the optic nerve at the back of the eye, thus damaging parts of the optic nerve. This damage appears as gradual visual changes and then loss of vision, if it remains untreated.. .
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The most common type of glaucoma,known as Chronic Open Angle( COAG ) or primary open angle, occurs when the canals darining the eye of aqueous humor become clogged.
This blockage can gradually increase pressure within the eye to damaging levels. no pain occurs,so indiduals or usually unaware that these changes are occurring.
These are no erly signs or symptoms but over the years vision will be lost starting in the periphery and moving towards the central vision.
When eye pressure builds up rapidly ,it is called Acute Angle Closure Glaucoma.This type of glaucoma commonly occurs in indiduals who have narrow anterior chamber angles
In these cases,aqueous fluid behind the iris cannot pass through the pupil thus pushing the iris forward,preventing aqueous drainage through the angle.
It is as through a sheet of paper floating near adrain suddenly drops over the opening and blocks the flow out of the sink.In cases of acute angle closure glaucoma,one may experience blurred vision .