HMD - Head Mounted Display
A device worn on the head to provide a personal computing display. HMD's are typically low resolution devices, but recent advances have allowed for full VGA (600x480), SVGA (800x600), and higher with full color (6, 8, 12, 16, and 24 bit).
Mine is a hacked CyVisor DH4400. I have converted it from bi-optical to monocle use. It provides SVGA at 24bits and accepts standard PC video, NTSC, and PAL inputs.