Face Shields and Containment of COVID-19,
WHO: COVID 19 Situation Report 66
A Useful Face Mask For Endoscopic Examinations, JAMA, Nov. 1950
"For those persons doing bronchoscopic or laryngoscopic examinations, particularly in cases of tuberculosis, adequate protection has been sought. I have used the item described here for many years with adequate protection and vision. ... It is a face shield used in industry for protection from eye and face hazards. The shield consists of a composition head piece, which is adjustable, and a plastic, transparent face piece measuring 9½ inches (24 cm.) in length and 12⅜ inches (31 cm.) in width. The plastic face piece is removable and easily replaced with snaps and is easily cleaned ... The shield protects the entire face and permits the wearing of glasses without fogging".
Author Bernard Jaffe
Airborne vs. Droplet: Turbulent Gas Cloud of Opinions
Dan Diekema practices infectious diseases, clinical microbiology, and hospital epidemiology in Iowa City, Iowa. After giving an overview over current research and clinical discussion he comes to the conclusion:
"..., I’m confident that SARS-CoV-2 transmission is similar to that of other respiratory viruses we are used to encountering—for which experience suggests droplet + contact spread to be the primary route of transmission. The trick is determining under what conditions a higher-risk aerosol might be produced-