Optrex warming eye masks are activated by air and start to warm up once they are opened after you have placed the comfy mask over your eyes optrexs microsteam technology delivers a gentle warming steam thats designed to moisten and soothe your eyes after use eyes feel relaxed and revitalisedr r perfect to use while travelling before bed or whenever you want to relaxr fragrance free r comfortable straps secure the mask in positionr unique air activated microsteam technologyr suitable fo