A eye_data_validata_bit_mask defined in struct SingleEyeData to indicate which data's validness listed below. Usually, the data becomes invalid when eye closed.
enum SingleEyeDataValidity {
SINGLE_EYE_DATA_GAZE_ORIGIN_VALIDITY,/*!<The validity of the origin of gaze of the eye data */
SINGLE_EYE_DATA_GAZE_DIRECTION_VALIDITY,/*!<The validity of the direction of gaze of the eye data */
SINGLE_EYE_DATA_PUPIL_DIAMETER_VALIDITY,/*!<The validity of the diameter of gaze of the eye data */
SINGLE_EYE_DATA_EYE_OPENNESS_VALIDITY,/*!<The validity of the openness of the eye data */
SINGLE_EYE_DATA_PUPIL_POSITION_IN_SENSOR_AREA_VALIDITY/*!<The validity of normalized position of pupil */
};