1. Chronic open-angle glaucoma (the most common form) – the increase in intraocular pressure is slow and has a sneaky onset, as defects in the visual field develop gradually.
  2. Closed-angle glaucoma (narrow-angle glaucoma) – can cause acute glaucoma attacks with eye pain and eye irritation. This condition requires immediate laser therapy (iridectomy).
  3. Congenital glaucoma – appears in childhood.
  4. Secondary glaucoma – occurs as a consequence of other eye diseases, traumas, surgeries or tumours.
  5. Low pressure glaucoma – has a sneaky onset and is difficult to diagnose as intraocular pressure can stay normal.
  6. Ocular hypertension – increase in intraocular pressure without actual damage to the optic nerve.