Embodiments are disclosed that relate to tracking a user’s eye based on time-of-flight depth image data of the user’s eye are disclosed. For example, one disclosed embodiment provides an eye tracking system comprising a light source, a sensing subsystem configured to obtain a two-dimensional image of a user’s eye and depth data of the user’s eye using a depth sensor having an unconstrained baseline distance, and a logic subsystem configured to control the light source to emit light, control the sensing subsystem to acquire a two-dimensional image of the user’s eye while illuminating the light source, control the sensing subsystem to acquire depth data of the user’s eye, determine a gaze direction of the user’s eye from the two-dimensional image, determine a location on a display at which the gaze direction intersects the display based on the gaze direction and the depth data, and output the location.揭示有關於根據使用者之眼之時差測距深度影像資料追蹤使用者之眼的實施例。舉例而言，一個揭示的實施例提供眼動追蹤系統，眼動追蹤系統包括光源、感測子系統及邏輯子系統，感測子系統經配置以藉由具有未受拘束的基準線距離的深度感測器來取得使用者之眼之二維影像及使用者之眼之深度資料，邏輯子系統經配置以控制光源發射光，控制感測子系統以當點亮光源時獲得使用者之眼之二維影像，控制感測子系統以獲得使用者之眼之深度資料，從二維影像決定使用者之眼之注視方向，根據注視方向及深度資料來決定注視方向與顯示器交會處在顯示器上的定位，及輸出該定位。
