VASCULAR
- Microvascular infarction (diabetes, HTN)
- Internal carotid aneurysm or dissection
- PICA aneurysm
- Cavernous sinus thrombosis
- Brainstem infarct
INFECTIOUS/AUTOIMMUNE
- Multiple sclerosis
- Myasthenia gravis
- Graves' ophthalmolpathy
- Botulism
- Neurosyphilis
- Systemic lupus erythematosus
- Sarcoidosis
- Orbital cellulitis
- Sphenoid sinusitis
- Temporal arteritis
- Tuberculous meningitis
- Diphtheria
NEUROLOGIC
- Wernicke's encephalopathy
- Mass compressing nerves to extraocular muscles
- Pseudotumor cerebri
- Ophthalmocataract
- Ophthalmoplegic migraine
- Progressive supranuclear palsy
MUSCULOSKELETAL
- strabismus
- muscle entrapment (orbital blowout fracture)
MONOCULAR DIPLOPIA
- Refractive error
- Early cataract
- Lens dislocation
- Corneal opacity (scar, pterygium)