An electronic device such as a head-mounted device may have displays that are viewable by the eyes of a viewer through adjustable lenses. The adjustable lenses may be liquid crystal lenses. A camera and other sensors in the head-mounted device may monitor the eyes of the user and gather other information. Control circuitry in the head-mounted device may control the adjustable lenses based on measured characteristics of the eyes of the user such as interpupillary distance and direction-of-view. The control circuitry may match the distance between the centers of the adjustable lenses to the measured interpupillary distance and may align the lens centers with the measured direction-of-view. The adjustable lenses may have transparent electrodes that are supplied with time-varying control signals by the control circuitry.