Causes of unilateral vision loss

Painful

• acute angle-closure glaucoma
• optic neuritis
• open-globe injuries
• orbital cellulitis / endophtalmitis / panophtalmitis

 Painless

• central retinal artery occlusion (CRAO)
• central retinal vein occlusion (CRVO)
• retinal detachment
• retinal break
• vitreous hemorrhage
• macular disorders (macular degeneration / trauma / infective – toxoplasmosis, CMV)
• optic nerve ischaemic neuropathy (giant cell arteritis, diabetes, compression by mass)
• optic nerve toxic neuropathy (methanol)
• chiasmal visual loss – pituitary tumours / craniopharyngioma / meningioma
• neuro-ophtalmologic causes (pathology involving post-chiasmal optic tract – occipital lobe: infarction / tumour / AVMs)
• functional (hysteria / malingering)

With thanks to Yusuf.