Abstract: A device is presented for determining patient's pupils locations in natural reading mode. The device includes a target member with a reading material on its outer surface, and a video camera mounted within the target member. The target member is orientable by the patient in a manner corresponding to his habitual reading position. The video camera is disposed such that the patients eyes are located within the depth of field of the camera, the camera thereby acquiring an image of the patients' eyes in a frame of his spectacles in his habitual reading position.