Head-mounted device with active optical foveation

A pass-through camera in a head-mounted device may capture image data for displaying on a display in the head-mounted device. However, only low-resolution image data may be needed to display low-resolution images in the periphery of the user's field of view on the display. Therefore, the pass-through camera may only capture high-resolution images that correspond to the portion of the user's field-of-view that is being directly viewed and may capture lower resolution image data that corresponds to the real-world objects in the user's peripheral vision. To enable the camera module to selectively capture high-resolution images, the pass-through camera may include an image sensor with two or more pixel densities, a distortion lens, and/or one or more planar or curved mirrors. Any of the components in the camera module may be adjusted to change which portion of a scene is captured with high-resolution image data.