KillerLag 1 points 2y ago
There were a few commercial products a few decades ago involving an ultrasonic sensor put into sunglasses, with motors for vibration to sense how far something is. It was not a success, unfortunately.
There is something called a BuzzClip (https://imerciv.com/user-guide/index.shtml), that is something that can be clipped to clothing. It also uses an ultrasonic sensor with a vibrating motor. It works a little better, but it still has certain issues.