Architecture and designs of wearable display devices are described. According to one aspect of the present invention, at least one optical conduit is embedded in or integrated with a temple of the wearable display device. The optical conduit is used to transport an optical image from one end to another end, where the optical image is generated in an image source (e.g., microdisplay) in accordance with image data. The microdisplay is powered and receives the image data and control signals via an active optical cable.