The semiconductor device comprises one layer including interconnections 32a to 32d formed above a substrate 10, and an insulation layer 34 formed over said one layer, a cavity 40 being included in said one layer. In one embodiment, an optical system is provided that is configured to receive an image provided by an image generator and which forms a light path along which light is transmitted from the image generator to an eye of the user. The shell is positioned radially inside the throat support to cover the inner surface of the throat support.