- Open angle glaucoma is painless and does not have acute attacks. Its symptoms are gradual field vision loss and optic nerve changes.
- Closed angle glaucoma is on the other hand painful and includes acute attacks. Its symptoms are sudden ocular pain, seeing halos around lights, having a red eye, nausea, vomiting, headache, sudden decreased vision and fixed midriasis (mid-dialet pupils).
Though, glaucoma in general is classified into primary, developmental, secondary and absolute.