<prompt> An elderly male with hea disease presents with sudden loss of vision in one eye; examination reveals cherry red spot; diagnosis is:Central retinal vein occlusionCentral retinal aery occlusionAmaurosis fugaxAcute ischemic optic neuritis  <response>: B i.e. Central Retinal Aery Occlusion Central retinal aery occlusion characteristically presents with sudden painless loss of vision, cherry red spot cattle-truck appearanceQ of retinal veins usually. Source of emboli from carotid aery hea disease, and thrombus from aeriosclerosis along with hypeension aeritis are predisposing factors. 