It may even play a part in standard desktop usage. One machine was set up to run at 75fps on a 75Hz refresh, and the other to run at 75fps on a 150Hz refresh. At the end of the test I got each volunteer to make a judgement as to their resultant level of neuralgia. The following day I repeated the test but with the machines swapped around. Now I know that this wasn't a particularly robust test, but the fact that a higher refresh-rate may under certain circumstances actually be worse for the eyes might surprise some people.
Conclusions There is really only one.
To produce maximal image clarity and to help alleviate fatigue, it is imperative that image changes are performed at the same rate as the refresh-rate of the display medium. Although simple tests and observations support the previous conclusions, I would still be interested in hearing from anyone who can devise some more robust tests. The only one remaining doubt in my mind derives from the operation of a movie projector. In this way each unique frame is displayed for three refresh periods.