Edward O’Brien patented this “body-attached rearview mirror” in 1905 “to facilitate the dressing of the hair and the inspection of the back of the head and head dress.” Essentially it’s a harness that bears three mirrors and an illuminating bulb, replacing a bothersome hand mirror.
“By this means, both hands of the wearer are free to properly arrange the head dress, brush the hair and the like, without disturbing the adjustment of the mirror and illuminating means.”
Just remember to take it off afterward …