Differentiate monocular vs. binocular
Monocular suggests medial pontine stroke or medial longitudinal fasciculus damage
Look for contralateral internuclear opthalmoplegia (INO)
Differentiate between central versus peripheral lesions
Monocular suggests medial pontine stroke or medial longitudinal fasciculus damage
Look for contralateral internuclear opthalmoplegia (INO)
Optokinetic reflex develops ~6 months of age
Slow pursuit of eyes towards direction of vertical bar movement with quick saccade towards the opposite side to find the next bar to fixate on
Abnormal in congenital<unk> 
In parietal or parietal-occipital lesions, optokinetic<unk>  is impaired when the drum is rotated towards side of lesion
See OKN drum to the right
See OKN drum to the left
See OKN drum to the right
See OKN drum to the left
Trace H in space
The best clinical test for the Vestibulo-Optic reflex
Water irrigated into the external auditory canal will exaggerate<unk>  if present
Temperature of the irrigated water will control the direction.
Cold water will exaggerate a<unk>  to move contralaterally
Warm water will exaggerate a<unk>  to move ipsilaterally
Cold water will exaggerate a<unk>  to move contralaterally
Warm water will exaggerate a<unk>  to move ipsilaterally
COWS: Cold Opposite, Warm Same.
Nystagmus
Optic nerve hypoplasia
Internuclear ophthalmoplegia
Macular disease
Ataxia
Noonan syndrome
Ataxia 
Head trauma, tympanic membrane rupture