I am going to use separate haar cascades to detect left and right eyes. My question is: is haarcascade_mcs_lefteye.xml applicable to the left eye of the person on the photo or to the eye at the left from the observer’s point of view? I cannot decide on my own because both haarcascade_mcs_lefteye.xml and haarcascade_mcs_righteye.xml detect both eyes on the photos that I have tried.