Stereo Goggles
Stereo vision is often included in a VR system. This is accomplished by creating two different images of the world, one for each eye. The images are computed with the viewpoints offset by the equivalent distance between the eyes. There are a large number of technologies for presenting these two images. The images can be placed side-by-side and the viewer asked (or assisted) to cross their eyes. The images can be projected through differently polarized filters, with corresponding filters placed in front of the eyes. Anaglyph images user red/blue glasses to provide a crude (no color) stereovision.
Head Mounted Display
Others use some sort of helmet or goggles to place small video displays in front of each eye, with special optics to focus and stretch the perceived field of view. Most HMDs use two displays and can provide stereoscopic imaging. Others use a single larger display to provide higher resolution, but without the stereoscopic vision. • Most lower cost HMDs ($3000-10,000 range ) use LCD displays, while others use small CRTs, such as those found in camcorders. The more expensive HMDs use special CRTs mounted along side the head or optical fibers to pipe the images from non-head mounted displays. ($60,000 and up). A HMD requires a position tracker in addition to the helmet. Alternatively, the display can be mounted on an armature for support and tracking (a Boom display).