Eye movements by extra-ocular muscles and cranial nerve innervation

Monocular Diplopia

  • Double vision that persists when one eye is closed
  • Related to intrinsic eye problem[1]

Binocular Diplopia

  • Double vision that resolves when the other eye is closed
  • Related to a problem with visual axis alignment[2]

3 Main Causes Binocular Diplopia

  • Eye Musculature Dysfunction
  • Cranial Nerve Dysfunction
  • Brainstem or Intracranial process

Clinical Features


  • Determine Monocular vs Binocular
  • Eval for Visual Field Defect
  • Evalulate for Visual Acuity
  • Determine if there is a Cranial Nerve Deficit
  • Check extraocular muscle function
  • Entrapment will show extraocular muscle restriction with extremes of gaze

  • Multiple cranial nerve involvement suggests an intracranial process or cavernous sinus involvement
  • Sudden painful or non painful onset suggest a vascular cause such as thrombosis, dissection, ischemia, or vasculitis
  • Other neurodeficits should raise suspicion for a CVA or MS
  • Systemic illness is more likely with meningitis involving the brainstem
  • Bilateral symptoms are more likely with neuromuscular problems such as Miller Fischer syndrome, Botulism, or Myesthenia

Differential Diagnosis

Algorithm for the Evaluation of Diplopia

Monocular Diplopia

  • Cataract
  • Lens Dislocation
  • Macular Disruption

Binocular Diplopia



  • Slit Lamp Exam
    • Assess for Cataract
    • Lens Symmetric
    • Posterior Orbital Mass
    • Macular Dysruption
  • Consider Ophthalmology Consult
  • Consider Ocular Ultrasound


  • Third nerve palsy: eye is down and out
    • Always needs CTH/CTA to r/o aneurysm given that nerve runs under PCA
  • Fourth nerve palsy
    • These are tough to catch and can be referred to optho outpt for prisms
    • No imaging needed unless other deficits present
  • Sixth nerve palsy: eye can't track laterally
    • Children need imaging to r/o tumor
    • In > 50, m/l ischemic and can get MRI outpt or just watch, assuming no papilledema as it can cause isolated CN VI palsy
    • If other nerves/deficits noted, consider MRI and further wu
  • Other imaging studies also include:
    • CTH with and without contrast ± CTA neck to rule out dissection and intracranial mass
    • MRV or CTV to eval for cavernous sinus thrombosis
    • CT orbits w/ contrast to eval for orbital apex syndrome (like CST above, but with CN II involvement)
    • MRI + DWI to if concern for CVA
    • MRI ± MRA if unable to classify intracranial process on initial contrast CT with contrast
    • MRI if concerned for MS


  • Neurology or Neurosurgical consult is warranted if evidence of an Intracranial bleed, Aneurysm or CVA
  • Metabolic workup to rule out diabetes or cause of mononeuropathy
  • If concern for basilar meningitis perform Lumbar Puncture


Depends greatly on the cause of the diplopia

  • Monocular Diplopia - can generally have opthalmology follow-up unless there is evidence of an open globe,
  • Binocular Diplopia

Neurology or Neurosurgery consult is useful depending on the cause of diplopia

  • Isolated Cranial Nerve III and VI palsy can be discharge if close Neurology follow-up and cause due to diabetes, microvascular ischemia and intracranial process ruled out[5]

See Also

External Links


  1. Coffeen P, Guyton DL: Monocular diplopia accompanying ordinary refractive errors. Am J Ophthalmol 1988; 105:451
  2. Rucker JC, Tomsak RL: Binocular diplopia. A practical approach. Neurologist 2005; 11:98-110
  3. Kusner LL, Puwanant A, Kaminski HJ: Ocular myasthenia: Diagnosis, treatment, and pathogenesis. Neurologist 2006; 12:231-239
  4. Bushra JS: Miller Fisher syndrome: An uncommon acute neuropathy. J Emerg Med 2000; 18:427-430
  5. Sanders SK, Kawasaki A, Purvin VA: Long-term prognosis in patients with vasculopathic sixth nerve palsy. Am J Ophthalmol 2002; 134:81-84