Acute painless vision loss causes: 
– ischemic optic neuropathy 
– retinal artery occlusion 
– retinal vein occlusion 
– retinal detachment 

Cherry-red spot and narrowed retinal arteries are consistent with a central retinal artery occlusion 
– a branch retinal artery occlusion presents similarly but with vision loss to just part of the visual field and pallor to only a portion of the fundus