The metronome is a frequently used time-keeping tool in music instrument practice. However, if its speed is set beyond a comfortable level for the performer, their eye movement (EM) patterns can betray pressure that might have been placed on the visual processing system. The patterns of the eyes moving forward or back, (saccades); when the eye stops between saccades to take in visual information, (fixations) and/or the time taken to programme a saccade (saccadic latency), are indicative of processing ability and differ with expertise. What is not known is how various levels of speed demand might affect the EM patterns of musicians with differing sight-reading abilities. This study measured the EM patterns of expert and non-expert music sight-readers. Musical excerpts were played on a keyboard--initially at the individual's fastest speed ensuring accuracy and then at a metronome setting of 120MM. The study showed that imposing excessive relative speed demands on less skilled sight-readers resulted in an inability to sustain performance. While this result might be expected, examination of the EM patterns of the experts indicated that smaller speed increments relative to their fastest accurate speed, resulted in less processing stress.