In optometry, binocular coordination is measured subjectively. The result is subjective fixation disparity. In research different experiments have proven, that subjective and objective fixation disparity are different. A binocular eyetracker has to be calibrated. There are two well known calibration methods: associated and dissociated calibration. Objective fixation disparity is measured in arcMin. Therefore, the precision of the eyetracker plays a crucial role. Now, the investigators try to compare dissociated calibration with polarized filters and associated calibration under different test paradigms.