By now, followers of castAR already know that Jeri Ellsworth created the projected augmented reality glasses back when she worked for Valve Software. But not everybody knows that its invention was, well, an accident. I was trying to figure out why people got sick when they wore virtual reality rigs, said Ellsworth to us as we chatted in the tiny castAR booth tucked away in the corner of Moscone North during GDC 2014.