Virtual reality, otherwise known as VR, immersive media, or compute-simulated reality, is technology that replicates an environment that simulates having a physical presence in either the real or an imagined world. The virtual setting is constructed through sensory experiences such as touch, sight, hearing, and smell. This resultant simulated physical presence allows the user to interact with the world in question. The most popular form of VR is currently a head mounted display, or HMD, in which a tethered headset uses special curved lenses to stretch and magnify a screen across the subject's visual field. The first HMD's were released in the 1990's for gaming: the Virtual Boy developed by Nintendo (TYO: 7974), the iGlasses developed by Virtual I-O, the Cybermaxx developed by Victormaxx, and the VFX1 Headgear developed by Forte Technologies. There are also "narrow" virtual realities used for modern gaming that have been quite successful, such as the Wii Remote, the Kinect, and the PlayStation Move/PlayStation Eye, all of which follow and report motion input of the game's subjects to a console relatively accurately.However VR has become particularly indispensable in military training. It can simulate not only different environments and terrain, but different kinds of assailants as well. Recruits are able to train for combat in controlled environments, where a mistake's consequences are close to nill; the software also cuts down on the amount of time needed to reset a training drill, and so allows a soldier to prepare for many more possible scenarios in a shorter and shorter amounts of time. The Air Force in particular relies heavily on virtual reality when training people who aspire to become pilots-trainees can become familiar with the controls and technical difficulties of various aircraft without having to put an inexperienced pilot in the cockpit. Using VR to lower risk when coaching inexperienced students is already used in the medical field (for surgical residents), and may even become incorporated into police training in the near future.

Due to the technology's increasing popularity, numerous companies are working on a new generation of VR headsets. The famous Oculus Rift, for example, is a head-mounted display for gaming purposes developed by Oculus VR, an American technology company that was acquired by Facebook for $2 billion in 2014. Its rival, dubbed as the PlayStation VR (codenamed Morpheus) by Sony (SNE  ), requires a PS4 as opposed to a PC to run-and costs $399, prior to any accessories.

"We liken the state of virtual and augmented reality today as similar to the state of mobile phones 15 years ago," wrote analysts from investment bank Piper Jaffey in May of 2015. As of now, Business Insider places the market's value at approximately $37 million; some predictions place the virtual reality market as being worth around $62 billion by 2025. As the technology inevitably improves, it will become essential to everything from concerts, sports events, movies, video games, professional training, and more. Unfortunately, most VR companies remain private, which bars many investors from getting in on the fledgling market-the currently public companies that stand to profit the most from the growing VR sector are Facebook (FB  ), Google (GOOG  ), and Sony.