Today I saw a 75 YO Neuroscientist who complained of Ainisoconia for 5 years. He only started wearing glasses a few years ago and had no hx of lazy eye ir strabismus. His refraction was + 1.75 ou with small astigmatism sensory exam was perfect 20/20+ ou nl color plates, Amsler and 24-2 pupils equal no Rapd. He exhibited a tiny left hyper of 1-2 in primary which alternated to left hyper of 1-2 and back and forth every 13-16 seconds. He saccadic pursuit in vertical more in down than up an very minimal horizontal saccadic pursuit to right and left. Some noted conjugate torsion to righ and than to left of 2 degrees on iTorsion test. No evidence of third or aberrent regeneration or fatigue or nystagmus even between phases. No nystagmus retractorious or up gaze palsy. Corbett et al in Annals if neurology described this in markedly impaired pts in midbrain any body seen a form frust