Abstract: A system for gathering fixation distance calibration data may include eyeglasses with adjustable lenses and an electronic device with a depth sensor. During fixation distance calibration operations, a user wearing the eyeglasses may view the electronic device while the electronic device provides instructions for the user to hold the electronic device at different distances from the user. At each distance, a depth sensor in the electronic device may determine the distance to the eyeglasses and a camera in the eyeglasses may be used to determine a distance between the user's pupils. The calibration measurements may be used to generate calibration data that maps different pupil locations to different fixation distances. The calibration data may be stored in the eyeglasses so that control circuitry in the eyeglasses can determine a user's fixation distance and adjust lens power accordingly without requiring an outward facing depth sensor in the eyeglasses.