Definition

The optic nerve serves as a means for light taken into the eye to travel to the brain and be interpreted. When the vitreous fluid of the eye changes in consistency or amount, this damages the optic nerve causing glaucoma.

Ocular Pressure

Glaucoma is caused when the ducts that drain the fluid that circulates within the eye fail to function properly. Most types of glaucoma can be attributed to increased ocular pressure caused by fluid buildup.

Artheriosclerosis

In low-tension glaucoma the optic nerve becomes damaged even though intra-ocular pressure remains normal. According to The Mayo Clinic, some researchers believe that this is caused by an underlying condition such as artheriosclerosis, which may reduce blood flow to small capillaries feeding the nerve.

Dislodged Pigment Granules

Pigmentary glaucoma results when pigment granules from the iris become dislodged and build-up on in the intra-ocular draining ducts. These temporary increases in fluid buildup damage the optic nerve and cause glaucoma.

Structural Changes

Glaucoma can also be the result of structural changes that occur within the eye from fluid ocular fluid imbalances. An increase or decrease in ocular fluid can change the shape of the lens of the eye, distorting vision.

Source:

National Eye Institute: Glaucoma

Mayo Clinic: Glaucoma

More Information:

Glaucoma Research Foundation