Virtual reality headset

A virtual reality headset, or VR headset, is a head-mounted device that creates a digital environment.

It uses 3D near-eye displays and positional tracking to immerse a user in a virtual world. While many people use these devices for video games, they serve many other important roles. They are used in simulators and professional training programs across many industries. Some advanced versions are called mixed reality (MR) headsets.

These allow users to see and interact with the real world alongside digital objects. Notable examples of MR technology include the Apple Vision Pro and the Meta Quest 3.

To make a virtual world feel real, the headset uses several complex mechanisms. First, it employs a stereoscopic display. This means it provides a slightly different image to each eye to create depth. The device also uses stereo sound to match the visual experience. To track movement, headsets use sensors like accelerometers and gyroscopes. These sensors track the pose of the user's head. This allows the virtual camera to match the orientation of the user's eyes in the real world.

Many devices use at least one MEMS IMU for three degrees of freedom (3DOF) motion tracking. Some use more advanced six degrees of freedom (6DOF) tracking. This often requires a sensor fusion algorithm, such as a Kalman filter. This algorithm merges data from the IMU and other sources, like outward-facing cameras, to track movement accurately.

There are different ways a headset can connect to a computer system. Many traditional headsets rely on a powerful personal computer to operate. However, some modern devices are known as "standalone" headsets. These are based on mobile operating systems and hardware similar to a smartphone. They can run VR applications directly on the device. They can also stream applications from a PC via USB or Wi-Fi. Another type of viewer is designed for smartphones. These use the phone's own screen and lenses to act as a stereoscope.

History shows that VR technology has evolved significantly since the late 20th century. VPL Research produced early headsets during the 1980s. In 1991, Sega announced the Sega VR, which later appeared in an arcade attraction in 1994. Sony released the Glasstron in 1997, which allowed users to see their surroundings while immersed. Despite these efforts, early headsets struggled commercially. Developer John Carmack once described the experience as looking through "toilet paper tubes." The modern era began in 2012 with Palmer Luckey's Oculus Rift crowdfunding campaign.

Facebook acquired Oculus VR in 2014 for $2 billion. This sparked a wave of new releases, including the PlayStation VR in 2016 and the HTC Vive in 2016.

Visual quality in VR depends on several technical factors. Image clarity is determined by display resolution, optic quality, refresh rate, and field of view. Because VR stretches a display across a wide field of view, flaws become very obvious. One common issue is the "screen-door effect." This happens when the gaps between pixels become visible to the user. To manage focus, headsets use specialized lenses. Fresnel lenses are common because they are compact and lightweight.

However, these lenses can cause distortion or chromatic aberration. Software is often used to correct these visual errors. Some high-end systems even use servomotors to adjust lens positions for a user's eyeglass prescription.

Latency is a critical requirement for a safe VR experience. Latency is the time between a user's movement and the visual response. If the system is too slow, it can cause virtual reality sickness. This is a form of motion sickness. Engineers suggest that ideal latency should be between 7 and 15 milliseconds. To help with processing, a technique called foveated rendering is used. This uses eye-tracking hardware to focus high resolution only where the user is looking. This reduces the workload on the graphics processing unit (GPU).

Today, VR is a vital tool in several professional fields.

In medicine, students use headsets to practice surgeries on virtual patients. This provides a risk-free environment where they can pause or rewind procedures. The military also uses VR for ground combat training. This allows personnel to interact with virtual people and practice scenarios without real-world danger. Additionally, companies use VR for health and safety training. Employees can practice responding to fires or chemical spills safely. This makes training more engaging and helps reduce real-world costs.