Dr. Max Snodderly and colleagues recently published an article in Vision Research entitled 'Eye movements between saccades: Measuring ocular drift and tremor". The paper describes guidelines to assess the precision and resolution of eyetracking systems and analyses and compares the intersaccadic eye movements of humans to those of a non-human primate.
Ko HK, Snodderly DM, Poletti M. Eye movements between saccades: Measuring ocular drift and tremor. Vision Research. 2016. doi:10.1016/j.visres.2016.03.006