A basic question in cognition is how visual information obtained in separate glances can produce a stable, continuous percept. Previous explanations have included theories such as integration in a trans-saccadic buffer or storage in visual memory, or even that perception begins anew with each fixation. Converging evidence from primate neurophysiology, human psychophysics and neuroimaging indicate an additional explanation: the intention to make a saccadic eye movement leads to a fundamental alteration in visual processing itself before and after the saccadic eye movement. We outline five principles of 'trans-saccadic perception' that could help to explain how it is possible - despite discrete sensory input and limited memory - that conscious perception across saccades seems smooth and predictable.