A switchable grating may be used to redirect illuminating light for illuminating a user’s eye in an eye tracking system, to facilitate the determination of eye position and/or orientation. The eye tracking system may be used in a near-eye display. An eye tracking camera obtains an eye image, and a controller performs an initial determination of the eye position. The controller may switch the switchable grating to direct the illuminating light beam onto the eye, for a better position and/or eye orientation determination.