Temporal fixation stability. Values are mean±SD of 68% BCEA (the upper table), the horizontal (X) and vertical (Y) fluctuations (the lower table) in the normal (Normal) patients, patients with MG without diplopia (MG diplopia−), patients with MG with diplopia (MG diplopia+) and SO palsy groups during the first (0–20 s), second (20–40 s) and third (40–60 s) fractions in the fixation period