A head mountable device for measuring eye movement of a user, the head mountable device includes: a frame a camera system comprising a first camera, wherein the camera system is configured to obtain a first set of images of a first eye of the user and a projection system for projecting a first projection comprising a visible object in a field of view of the first eye when the user wears the head mountable device, wherein the projection system is configured to move the visible object relative to the head mountable device.
