Abstract: An electronic device may have a display panel with an array of display pixels. Light from the display panel may be focused by a lens assembly towards a viewer. The presence of the lens assembly may cause geometric distortion for a viewer viewing images on the display through the lens assembly. To mitigate geometric distortion, geometric distortion compensation may be performed in the electronic device. The electronic device may include both a fixed lens element and a removable lens element in the lens assembly. The removable lens element may be changed, allowing the distortion function associated with the lens assembly to change over time. To dynamically compensate for geometric distortion caused by a lens assembly with a removable lens, ray tracing may be used to determine the geometric distortion caused by the lens assembly depending upon the particular removable lens that is present in the lens assembly.

Abstract: A head-mounted display may display images in eye boxes. Right and left gaze tracking sensors may gather left eye gaze information from a left eye box and right eye gaze information from a right eye box. During operation in a first mode in which the right and left gaze tracking sensors are not impaired, gaze information from the right and left gaze tracking sensors may be used in presenting foveated and distortion-corrected image content on the displays and/or in otherwise operating the left and right displays. During operation in a second mode in which one of the gaze tracking sensors is impaired, gaze information for the impaired sensor may be estimated from gaze information for the unimpaired sensor in combination with an object depth estimate based on depth buffer information, vestibulo-ocular-reflex gain information, and historical information.