A wireless hands-free portable headset computer with a micro display arranged near but below a wearer's eye in a peripheral vision area not blocking the wearer's main line of sight. The headset computer can display an image or portions of an image, wherein the portions can be enlarged. The headset computer also can be equipped with peripheral devices, such as light sources and cameras that can emit and detect, respectively, visible light and invisible radiation, such as infrared radiation and ultraviolet radiation. The peripheral devices are controllable by the wearer by voice command or by gesture. The headset computer also can be broken down into component parts that are attachable to another article worn by an individual, such as a helmet or respirator mask.