When fixating our eyes appear still
Sensitive devices measure miniature movements
Fixation eye movements include
High frequency (mircotremor)
Slow drifts
Micro saccades
Slow drift: both eyes work together in light
Separate from each other in dark
Micro saccades are
Involuntary
Unlike tremor and drift, micro saccades are always
Binocular and correlated
Error correcting