An induced draft anti-fog system for goggles and similar optical devices having an air tight goggle with ports, fixedly attached to a hollow elastomeric conduit. Said hollow conduit having an intake port and exhaust fan. The exhaust fan has an on/off switch in communication with two battery packs. When the fan is in operation air is drawn into the intake port and circulated into the goggle housing thereby defogging the goggle lens and then is circulated out through the fan.