Some of the causes of acute vision loss are:

• Cardiac Causes include:
  • Emboli -- causes can be atherosclerotic plagues, atrial fibrillation, endocarditis.
  • Arteritis
  • Dissection
• Hematologic causes
  • Hypercoaguable state
  • Hyperviscosity
  • Anemia
• Ocular Causes
  • Angle-closure glaucoma
  • Papilledema/neoplasm: Intracranial hypertension
  • Intraocular foreign bodies:
  • Central retinal artery occlusion
  • Anterior ischemic optic neuropathy
  • Ruptured globe
• Miscellaneous
  • Migraine
  • Hysteria
  • Drugs (i.e.: viagra and its counterparts)

References

Farino GA, Feliciano A, Lorenzo NY. Sudden Visual Loss.  eMedicine. Accessed November 27, 2009.