A WOMAN NAMED Melanie in Ventura, California had a strange experience while sitting on her own living room sofa. While just staring at the wall, she became, she believes, invisible. Her husband walked around the house looking for her. He even walked right by her - just a few feet away - and did not see her. The episode lasted about 10 minutes, then suddenly she was visible again.
This unusual story is one of several documented by Donna Higbee who is conducting extensive, ongoing research into a phenomenon she calls Human Spontaneous Involuntary Invisibility. According to the anecdotes Higbee tells at her website, The Research and Writings of Donna Higbee, people suddenly and unexpectedly become invisible. They don't seem to feel any differently when this occurs, and they can see and move around normally, just as if nothing has changed. Yet other people don't see them. They are ignored - totally - as if they aren't there.
Full Story: About.com
(*NOTE - The article by Donna Higbee (linked in the story) is quite interesting. However, I have lived in Ventura more than 35 years and have never heard of "Vera" or "Melanie" or anyone else in town becoming invisible. )