[sevenless]

Sonar or lidar is a great idea if it can be made really small and not use much power.

Simply, don't include a camera, and make it obvious there's no camera - make the conspicuous bit transparent. You don't need a camera for many applications, like a GPS based heads up map display.

[witty_username]

Maybe make the camera physically detachable? And some easy indicator to show whether the camera is plugged in or not?