A personal breathing device for filtering, diffusing, and conditioning air inhaled by a person. The device includes an eyewear frame with an attached nose piece and air-permeable membrane which is positioned to surround the nose and permit normally inhaled volumes of air to pass through the membrane as the air is inhaled, and thereby filter and condition the inhaled air. The device can be conveniently placed on and removed from the face, does not obstruct speech, and is suitable for wearing during a variety of normal daily activities to filter and condition inhaled air. The air permeable membrane can be impregnated with various liquids or other agents to enhance filtering and antimicrobial functions, or to provide cooling, moisturizing, or scenting of the inhaled air. The device can be provided with a detachable air permeable membrane which can be easily replaced as needed.