The Head Mounted Display, or HMD was one of the first true VR interfaces. It has gone through many changes over the years, and introduced new medical conditions. HMDs remain popular even today, but what are these strange boxy devices? How do they work?

In early 2005, Icuiti corporation produced the V920. The first commercially released HMD/HUD hybrid. Now, in early 2007, it seems they have changed their minds, and greatly modified the v920 into three new models, each one an advancement over the original. Here, we examine the VR920.

It is an icon of past failures of VR. The Virtual Boy, once hailed by Nintendo as the future of gaming. All the basic science is sound, and the concept was a good one, so where did this abortive attempt to revolutionise interfaces, go so terribly wrong?

A look at the Sega VR, a head mounted display and fully immersive interface of the early 1990s, that somehow never quite managed to make it off the ground.

Bad name puns aside, CamAR is exactly what it sounds like. Its an augmented reality camera system. Designed by Vuzix, it clips onto the outside of their VR920 virtual reality video eyewear, turning the 400 usd device into an augmented reality visor.

What if you could take the physical world, and overlay virtual reality images directly onto it? See the physical world, but with bits added from computer mediation? The Heads Up Display, or HUD is one method of doing this.

The SportVue heads-up display for motorcycles and other motion sports is designed to augment the rider?s vision with a continuing display of computerised data about the terrain, weather warnings, their speed, and exact location on the course, without taking their eye off the path ahead.

The Perspecta display system was released by Actuality Systems in May 2005. Its intended purpose is as a 3D volumetric display capable of projecting a virtual object right in front of you.

The Dextroscope is a holographic display system designed specifically to help surgeons visualize and practice on the area to be operated on, prior to actual surgery.

A technical look at the Perspecta suspended display system, released by Actuality Systems in May 2005. Its intended purpose is as a 3D volumetric display capable of projecting a virtual object right in front of you.

Remember StarWars? That iconic moment when the hologram of Princess Leia is projected from R2 D2? Heliodisplay is that technology made real. It is literally, the production of holograms that hover in thin air.

The virtual laser keyboard first appeared in mid 2005, and is a product of machine vision and projection technology. The emitter itself is about the size of a small mobile phone, and so can be discretely attached to any handheld device.

The Binocular Omni Orientation Monitor or BOOM was one of the very first immersive VR interfaces, predating even the HMD. Massive and unwieldy, they none the less have some valuable properties which still see them in use today.

Released December 2005, the CyberMan GVD510-3D head-mounted display is a stereoscopic display unit, with a resolution of 640 x 480. Made by Kopin Corporation, China, this unit is essentially part of the new trend of video eyewear, combining HUD and HMD in one device.

The first of the ?video eyewear? phenomenon, the Icuiti V920 arrived in the world in early 2005. This thin strip was the first time the concept of a hybrid head mounted / heads up display had been launched. It turned out to be quite a nice unit, certainly betterthan many attempts since.

At CES 2009, Nvidea unveiled a system of active glasses. Specifically, shutter glasses. The frames alternate polarisation to block light out every second frame, so that each eye gets half the screen update rate of any normal monitor, but will work with a normal output stream just fine.

Taking a look at shutter glasses, one of the staple technologies for sterioscopic vision in VR and AR.

eMagin Corporation's Eyebud 800 personal display system. This is a video eyewear display, which is specifically designed to interface with an ipod.

Logitech's G19 keyboard is in its own way, a serious attempt at a mainstream VR interface. It is designed as a gamers keyboard, attempting to heighten immersion for gaming for the majority of users who do not touch-type. The board actually has an adjustable liquid crystal monitor built into the back of it, above the function keys.

In early 2005, Icuiti corporation produced the V920. The first commercially released HMD/HUD hybrid. Now, in early 2007, it seems they have changed their minds, and greatly modified the v920 into three new models, each one an advancement over the original. Here, we examine the AV920.

In early 2005, Icuiti corporation produced the V920. The first commercially released HMD/HUD hybrid. Now, in early 2007, it seems they have changed their minds, and greatly modified the v920 into three new models, each one an advancement over the original. Here, we examine the DV920.

A different sort of iWear device, Vuzix's AV 230XL is panoramic, yet designed solely for audio-visual playback, not for interactivity,

In November 2008, Vuzix (formerly Icuiti) launched two new additions to their video eyewear range, designed to make you look like Geordi La Forge from Star Trek. One of these new HMDs, the AV 310, is something of a first. It is a widescreen head mounted display, specifically designed for 16:9 format.

The Barco 42 inch HDTV, specially designed for use in operating theaters, and DICOM data networks, is one of the first of a new breed of display device, delivering up to the second information to the surgeon.

The Barco R-360 is a double hemisphere display system for flight simulation that offers carefully balanced highly dynamic displays of up to 140 megapixel, completely surrounding the user.

A curious device, a biowall installation - several exist at this current time - is in essence, an organically growing computer composed of inorganic modules. It might almost be described as an ultimate augmented reality system of a sort.

BrainLab?s Digital Lightbox is essentially a single-screen geowall interface. Looking like nothing so much as a vastly oversized iPhone, this flatscreen display sits long ways on the wall, and is as many display screens as the users need it to be at the time.

The Star CAVE is the first of the third generation of CAVE VR interfaces - Computer Augmented Virtual Environments. As its name suggests, it is star-like in that it has five corners, like an pictographic star. However, the outline of its form resembles a pentagon, not a pentagram.

Virtual sight devices, sometimes termed virtual light, are a class of display system which is a mix of AR, prosthetics, and VR. They have no actual display units as such, and completely bypass the human eye. Instead, they tap into the optical nerve directly, and deliver processed information to the neurons heading into the brain.

The 'virtual light' class of retinal displays, are perhaps unique in the display industry, because they don't actually display anything. The entire concept is built round bypassing the eye entirely, and dropping visual encoded information directly into the optic nerve.

Augmented reality tagging has begun to creep forwards as a technology for some years now. If you can co-ordinate virtual data with physical locations, you can tag something, and correlate to a virtual database. Researchers at the University of Tokyo have developed a system which is designed as a memory aid for the elderly, to build on this concept.

It may look a little ungainly, and perhaps not best for use in outside environments, but the EyeSeeCam, developed by biomedical engineers and clinical neurologists at the University of Munich Hospital, is camera designed to store and transmit the exclusive point of view of its wearer's eyes.

At CHI 2009 (computer Human Interaction conference,) many new modalities of interface were demonstrated. One of the more practical was the product of a team from ETH Zurich's Wearable Computing lab. Vaguely resembling the bastard child of a set of safety glasses and a HMD, the EOG goggles are an eye movement tracking system, that requires no external hardware to operate.

The Readius is a rollable display unit, no larger than a pocket tape recorder. It has been 'about to be released' since late 2006, but is finally making steps towards commercial viability. The technology of foldable electronic paper, taken one step further to that of rollable electronic paper, in an attempt to make such displays as lightweight and convenient as possible.

A low-budget native DICOM supporting digital/analogue projector, designed to handle complex and subtly shaded medical data from every DICOM compatible device, in the training and presentation environment.

A native DICOM supporting digital/analogue projector, designed to handle complex and subtly shaded medical data from every DICOM compatible device, in the training and presentation environment.