Described herein is an eye tracking system comprising an image display configured to display an image of a surgical field to a user. The image display is configured to emit a light in first wavelength range. The system further comprises a right eye tracker configured to emit light in a second wavelength range and to measure data about a first gaze point of a right eye of the user. The system further comprises a left eye tracker configured to emit light in the second wavelength range and to measure data about a second gaze point of a left eye of the user. The system further comprises an optical assembly disposed between the image display and the right and left eyes of user. The optical assembly is configured to direct the light of the first and second wavelength ranges such that the first and second wavelengths share at least a portion of a left optical path between left eye and the image display and share at least a portion of a right optical path between the right eye and the image display, without the right and left eye trackers being visible to the user. The system further comprises at least one processor configured to process the data about the first gaze point and the second gaze point to determine a viewing location in the displayed image at which the gaze point of the user is directed.
