Microsaccades are the largest and fastest of the fixational eye movements, which are involuntary eye movements produced during attempted visual fixation. In recent years, the interaction between microsaccades, perception and cognition has become one of the most rapidly growing areas of study in visual neuroscience. The neurophysiological consequences of microsaccades have been the focus of less attention, however, as have the oculomotor mechanisms that generate and control microsaccades. Here we review the latest neurophysiological findings concerning microsaccades and discuss their relationships to perception and cognition. We also point out the current gaps in our understanding of the neurobiology of microsaccades and identify the most promising lines of enquiry.