A lightweight face shield which protects the face of the wearer from debris and/or hazardous materials, such as biological materials, and is particularly well suited for medical and dental applications. The face shield utilizes a two-piece tiered structure with a preferably canted retention frame joined...http://www.google.co.uk/patents/US7490359?utm_source=gb-gplus-sharePatent US7490359 - Lightweight ventilated face shield frame
