Glaucoma is a group of eye diseases that damage the optic nerve
and cause vision loss. It is usually caused by increased pressure
in the eye, known as intraocular pressure (IOP), which damages the
optic nerve that transmits visual information from the eye to the
brain. If left untreated, glaucoma can lead to permanent blindness.

Glaucoma often develops slowly and can be asymptomatic in its early stages.
As the disease progresses, it may cause the following symptoms:

• Gradual loss of peripheral vision
• Tunnel vision
• Blurred or hazy vision
• Severe eye pain
• Headaches
• Eye redness
• Nausea or vomiting

There are several types of glaucoma, the most common ones being:

1. Open-angle glaucoma:
   This is the most common type of glaucoma, characterized by a gradual
   clogging of the drainage canals, resulting in increased eye pressure.
2. Angle-closure glaucoma:
   This type occurs when the iris is too close to the drainage angle,
   blocking the flow of fluid and causing a sudden increase in eye
   pressure.
3. Normal-tension glaucoma:
   In this type, optic nerve damage occurs even with normal intraocular
   pressure levels.

Glaucoma can be diagnosed through various tests, including:

• Comprehensive eye exam
• Visual field test
• Tonometry to measure intraocular pressure
• Optic nerve evaluation

While there is no cure for glaucoma, the progressive loss of vision can
usually be controlled with the following treatment options:

• Medication:
  Eye drops or oral medications are commonly prescribed to reduce intraocular
  pressure.
• Laser therapy:
  Laser trabeculoplasty or iridotomy can help improve drainage and lower eye
  pressure.
• Surgery:
  In advanced cases, surgical procedures like trabeculectomy or shunt implantation
  may be necessary to enhance fluid drainage.