Internuclear ophthalmoplegia is the inability of eye to adduct properly. Normally when we look towards an object both eye balls move towards that side in a conjugate lateral gaze. But in INO the effected eye is not able to cross the center point when looking towards the opposite side and also causes nystagmus of contralateral eye. This is caused by lesion in the medical longitudinal fasciculus which is a collection of nerve fibers from all cranial nerves III, IV and VI in the brainstem. The condition is the result of: stroke, Multiple sclerosis, Lyme's disease, brainstem encephalitis, Bechet’s disease, fungal infection (cryptococcus), Gullain Barre syndrome, systemic lupus erythematous, trauma to head and neoplasms. The outlook of the disease is usually good if the cause is manageable. For example surgical removal of a cancer.