An eyeball is often likened to a single-joint limb, with three degrees of freedom for movement (horizontal, vertical, rotatory). For securing stable accurate vision, however, eyeballs are equipped with four major reflexes. These are evoked by vestibular and visual afferent signals, and they compensate for movements of the head and its environment. In this chapter we review current knowledge about these ocular reflexes and their cerebellar control. The four reflexes provide relatively simple control system models of cerebellar adaptation and compensation, and they have helped considerably in the design of robust experimental paradigms for testing several aspects of the function of the cerebellum.