Glaucoma is a disease that damages the optic nerve. It usually happens when fluid builds up in the front part of the eye. That extra fluid increases the pressure in the eye, damaging the optic nerve . leading to blindness over time  

the  eye makes (fluid ). As new aqueous flows into the  eye, the same amount should drain out  through an area called the drainage angle . This will keep the pressure in the eye normal. But if the drainage angle is not working properly, fluid builds up. causing damage to the optic nerve .

- Open-angle glaucoma: a gradual vissual loss , with out any warning signs or pain  .
- Acute closed-angle glaucoma include :
o Eye pain
o A sense of nausea .
o blurry vission  .
o Seeing halos around light .
o Redness of the eye .
- Normal tension glaucoma: these people have normal eye pressure but show symptoms of gluacoma , like vission loss and optic nerve damage

- medication including eye drops

Lasers
-eye surgery
-

- If left untreated glaucoma, it causes a loss of vision, usually graded through the following stages :
- Blind spots in the peripheral vision .
- Peripheral vision loss completely .
- Total blindness .