For years my left eye has intermittently caused bouts of SEVERE pain that sometimes lasted for days. Repeated attempts to diagnose have been unsuccessful and the physician assured me there's no way to relieve the pain. And furthermore, he's known it to make Navy SEALS emote.
Yesterday, after several years without an incident, I spent all day, from about 9 a.m. to 9 p.m. in such intense pain I lost control of my bowels. (I was in the hills near Baker City, Oregon.) I tried several times to use the Debreather but each time, after a few minutes, I felt as if I couldn't breath and had to stop. (See Richard's, the inventor of the Debreather, reply on the link above)
The headgear is part of the Debreather II. The chin strap keeps the mouth closed after a person loses consciousness. The fabric is velcro and holds the face-mask in place.