<prompt> The only intact eye movement in one and a half syndrome isAbduction of Ipsilateral eyeAbduction of contralateral eyeAdduction of Ipsilateral eyeAdduction of contralateral eye  <response>: One-and-a-half syndrome is due to a lesion of MLF combined with PPRF of same side. Loss of all horizontal movements except contralateral abduction, which shows abduction nystagmus. One and One half syndrome right sided lesion Eight and half syndrome consists of one and half syndrome with 7th nerve palsy. 