The present application relates to an apparatus for controllably rotating an object, such as a baseball or any sporting ball, and methods of using the apparatus for measurement of visual acuity and/or training. Specifically, in certain embodiments, an object is rotated at a selected revolutions per minute (RPM) and a subject's exposure to the rotating object is controlled by illumination and/or controlled exposure, and assessing a subject's ability to recognize the direction of rotation.