With an Automatic-Darkening Welding Helmet, its lenses are clear under normal lighting but automatically darken when the arc is ignited. This enables the user to always see clearly the working environment without his eyes having to adjust, eliminating the need to manually change lenses. Besides protecting the eyes, the helmet also guards face and skin from ultra-violet light radiation, harmful infrared light, and spatter; and its secure fit leaves the hands free for welding. (Some makes/models have as options a ventilation system that draws, filters, and blows air inside the helmet and/or side lenses to increase peripheral vision.)