A discussion on the role of smart glasses in the Industry 4.0 context firstly requires a classification on the different types of smart glasses. A taxonomy for smart eyewear allows to map use cases and business requirements of the industry with the strengths and weaknesses of each class. The gap between business reality and hardware aspiration is the basis to discuss future trends and the expected evolution. Smart glasses are a key component to provide human-centered support and to connect the desk-less operator with the IoT and other elements of the cyber-physical factory of the future.