Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 7 Sept 2026Clinical review pending
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Double vision with neurological or orbital warning signs
Acute diplopia with severe headache, pupil change, ptosis, neurological deficit, proptosis, fever or reduced vision may reflect a life-threatening neurological process or an orbital emergency.
Action: Arrange immediate emergency assessment for these combinations, record pupils and ocular movements and seek appropriate eye, stroke or neurological input; do not label a new palsy microvascular solely from age or diabetes.
Synopsis
Characterise double vision, examine ocular alignment and movement, and connect the pattern with the appropriate orbital, neuromuscular or neurological assessment.
Ask the patient to describe two distinct images, blur or distortion, then test the effect of covering each eye in turn.
Binocular diplopia resolves when either eye is covered; monocular diplopia remains when the affected eye views alone.
Record onset, intermittency, image separation, gaze dependence, near versus distance symptoms, pain, trauma and neurological or bulbar symptoms.
Key red flags
Sudden severe headache or an enlarged pupil with diplopia requires emergency assessment; pupil sparing does not independently exclude a dangerous cause of a new third-nerve palsy.
Investigation priorities
01
Sequential monocular occlusionFirst step
Distinguish binocular misalignment from doubling that persists through one eye.
Management branches
Symptom definitionEstablish what the patient sees
A patient reports new or recurrent doubling, ghosting or visual confusion.
Clarify onset, image orientation and gaze dependence, then cover each eye in turn to distinguish monocular from binocular symptoms.
Ask about pain, headache, trauma, previous squint, eye surgery, medicines and neurological or swallowing and respiratory symptoms.
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 7 Sept 2026; clinical approval remains outstanding.