Obstructed aqueous outflow tract → aqueous humor builds up → increased intraocular pressure (IOP) → optic nerve damage → vision loss
Increased posterior chamber pressure causes iris to bulge forward (iris bombé) → further obstruction of outflow tract  → further increase IOP<unk>  attack is usually precipitated by pupillary dilation
Acute angle-closure glaucoma
Nontraumatic
Open-angle glaucoma
Acute angle-closure glaucoma^
Orbital cellulitis
Anterior uveitis
Orbital compartment syndrome
Conjunctivitis