Sixth nerve palsy, or abducens nerve palsy, is a disorder associated with dysfunction of cranial nerve VI, which is responsible for contracting the lateral rectus muscle to abduct (i.e. , turn out) the eye. The inability of an eye to turn outward results in a convergent strabismus or esotropia of which the primary symptom is double vision or diplopia in which the two images appear side-by-side. The condition is commonly unilateral but can also occur bilaterally. The unilateral abducens nerve palsy is the most common of the isolated ocular motor nerve palsies .