Causes

• The cause of glaucoma has not been discovered. Some researchers believe the different types of glaucoma may have different causes.
  
  

Primary Open-Angle

• Primary open-angle is the most common form of glaucoma. Causes may be inefficient eye drainage, pressure buildup in the eye or inadequate blood flow to the eye. Angle-closure glaucoma is less common but may be caused by the same factors.
  
  

Secondary

• Secondary glaucoma occurs when there is eye injury or eye disease. Possible causes include eye abnormalities, medications and medical conditions.
  
  

Normal-Tension

• Normal-tension glaucoma results in damage to the optic nerve. The cause may be limited blood getting to the optic nerve, or an abnormally sensitive optic nerve.
  
  

Uncontrollable Risks

• Risk factors include age, ethnic background and family history. Anyone over 60 and also African-Americans have a greater risk of developing glaucoma.
  
  

Other Risks

• Other risk factors include being nearsighted, previous eye injuries, medical conditions such as diabetes and high blood pressure, and having elevated internal eye pressure.