Disclosed are a head mountable device and a method for measuring eye movement. The head mountable device comprising: 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 a user with a first frame rate and a first resolution, wherein the first frame rate is selected such as to enable the processing unit to detect eye saccades of the first eye.； a processing unit configured to process the obtained first set of images and providing a processor output based on the first set of images； an interface connected to the processing unit, for providing a device output based on the processor output.
