Table 4

 Common visual symptoms

Main visual symptomCausesClinical clues
Double vision (diplopia)Cranial nerve palsyAbnormal eye movements
Weakness of ocular muscles—for example, multiple sclerosis, myasthenia gravis, Guillain–Barré syndromeOften associated with other neurological symptoms and signs
Sudden visual loss
    CompleteCentral retinal vein occlusionAbnormal funduscopy
Retinal artery occlusion
Retinal detachmentFlashing lights
Optic neuritisAssociated with pain
    PartialStrokeAssociated with other neurological signs
Multiple sclerosisMay be other neurological symptoms/signs
GlaucomaPainful red eye, vomiting
    TransientTransient ischaemic attack, amaurosis fugaxRisk factors for cerebrovascular disease. May be other neurological symptoms
Migrainous auraOccur in approximately 80% of people with migraineUsually precede onset of headache
Typically flickering zigzag lines starting in centre of vision and gradually proceeding towards the periphery of one visual field often leaving a scotoma. Usually resolves in less than an hour