, spotted by on Tuesday, was originally filed by Apple in 2006, and is titled "Peripheral treatment for head-mounted displays". It describes apparatus that could project an image in a head-mounted device for the user to view.

"This invention relates to displaying images in a head-mounted display," reads Apple's patent description. "A head-mounted display (HMD) is a display device that a person wears on the head in order to have video information directly displayed in front of the eyes."

This could be achieved by embedding one or two small displays in a helmet, glasses or a visor, says Apple. With two displays, the HMD could show 3D stereoscopic images. It could also use reflective mirrors to create augmented reality, in which a see-through image is imposed on a real world view, Apple's patent describes.

Apple explains that augmented reality could be a benefit to surgeons, military, police, fire fighters, engineers and scientists, for example. It could also be used by consumers for gaming and entertainment purposes.

Apple's head-mounted display would be adjustable to ensure comfortable and effective use, and peripheral vision techniques could be used to prevent motion sickness.