imaging) is combined with the surgeon's natural view of the operation, and anesthesia, where the patient vital signs are within the anesthesiologist's field of view at all times. Research universities often use HMDs to conduct studies related to vision, balance, cognition and neuroscience. As of 2010, the use of predictive visual tracking measurement to identify mild traumatic brain injury was being studied. In visual tracking tests, a HMD unit with eye tracking ability shows an object moving in a regular pattern. People without brain injury are able to track the moving object with smooth pursuit eye movements and correct trajectory. Gaming and video Low-cost HMD devices are available for use with 3D games and entertainment applications. One of the first commercially available HMDs was the Forte VFX1 which was announced at Consumer Electronics Show (CES) in 1994. The VFX-1 had stereoscopic displays, 3-axis head-tracking, and stereo headphones. Another pioneer in this field was Sony, which released the Glasstron in 1997. It had as an optional accessory a positional sensor which permitted the user to view the surroundings, with the perspective moving as the head moved, providing a deep sense of immersion. One novel application of this technology was in the game MechWarrior 2, which permitted users of the Sony Glasstron or Virtual I/O's iGlasses to adopt a new visual perspective from inside the cockpit of the craft, using their own eyes as visual and seeing the battlefield through their craft's own cockpit. Many brands of video glasses can be connected to modern video and DSLR cameras, making them applicable as a new age monitor. As a result of the glasses ability to block out ambient light, filmmakers and photographers are able to see clearer presentations of their live images. The Oculus Rift is a virtual reality (VR) head-mounted display created by Palmer Luckey that the company Oculus VR developed for virtual reality simulations and video games. The HTC Vive is a virtual reality head-mounted display. The headset is produced by a collaboration between Valve and HTC, with its defining feature being precision room-scale tracking, and high-precision motion controllers. The PlayStation VR is the a virtual reality headset for gaming consoles, dedicated for the PlayStation 4. Windows Mixed Reality is a platform developed by Microsoft which includes a wide range of headsets produced by HP, Samsung, and others and is capable of playing most HTC Vive games. It uses only inside-out