Display 14 may have an active area and an inactive area. The active area may, as an example, be formed in a rectangular central portion of the front face of device 10. The active area contains pixels that display images for a user of device 10. Inactive border regions (areas without pixels) may be formed along one or more of the edges of the active area. For example, the active area may be bordered on the left and right and top and bottom by inactive display areas. In other configurations, the active area of display 14 may cover all of the front face of device 10, may cover the front face of device 10 and some or all of the sidewalls of device 10, may have inactive borders at the upper and lower ends of device 10 while being borderless along the left and right edges of device 10, or may have other layouts.

Components such as light sensors (e.g., light-sensors in proximity sensors, ambient light sensors, etc.), cameras (e.g., digital image sensors that capture images), status indicator lights (e.g., light-emitting diodes), and other components may be mounted under windows in display 14 such as windows 20 or other portions of device 10. Sensors such as proximity sensor light sensors may be mounted under a layer of visible-light-blocking and infrared-light-transparent material. Sensors such as ambient light sensors and other components that use visible light such as cameras and status indicator lights may be mounted under windows that are transparent to visible light. Light-based components such as these may also be mounted on the rear face of device 10, on device sidewalls, or in other portions of structures of device 10.