In one embodiment, an electronic device may include a light source configured to emit light that penetrates into a portion of a user's body, a plurality of light sensors configured to detect a pattern of diffusion of the emitted light, and a controller configured to detect a gesture made by the user based on the detected pattern of diffusion of the emitted light. The controller may be configured to control the light source and the plurality of light sensors to detect the gesture made by the user.
