Following are the causes of sudden loss of vision except
Sudden painless loss of vision  Central retinal aery occlusion  Massive vitreous hemorrhage  Retinal detachment involving macular area  Ischaemic central retinal vein occlusion The sudden painless onset of defective vision  Central serous retinopathy  Optic neuritis  Methyl alcohol amblyopia  Non-ischemic central retinal vein occlusion Sudden painful loss of vision  Acute congestive glaucoma  Acute iridocyclitis  Chemical injuries to the eyeball  Mechanical injuries to the eyeball Corneal ulceration causes Gradual painful defective vision Reference : AK KHURANA COMPREHENSIVE OPHTHALMOLOGY, Edi4, Page-462
Angle closure glaucoma
Endophthalmitis
Central serous retinopathy
Corneal ulceration
Anatomy, Development and clinical examination