Homonymous diplopia resulting from an abducens nerve paralysis is a not infrequent symptom which confronts the ophthalmologist. This symptom with the objective finding of deficient abduction on attempted lateral gaze is often the prelude of a more extensive neuro-ophthalmologic disorder yet to be unfolded. Many times, however, it remains the isolated expression of a disease process.1
This survey is designed to show the relative frequency of the various causes of isolated abducens nerve paralysis that the ophthalmologist is likely to see, because it concerns itself with only those cases that presented themselves initially to the ophthalmologist with complaints and findings referable to the abducens nerve alone. Such a study dealing in specifics should aid the clinician to settle more definitely the problem of etiology and to answer more precisely the question of prognosis, so ubiquitously similar.2
Only patients with acquired abducens nerve paralysis have been included in this