Augmented reality

Augmented reality (AR) is a technology that overlays digital content, such as images, text or three-dimensional models, onto a person’s view of the real world. The U.S. Food and Drug Administration (FDA) describes it as a real-world experience that mixes simulated digital imagery with the physical world as seen through a camera or a display, such as a smartphone screen, a head-mounted display or a heads-up display. The digital content can respond to the real surroundings. The FDA notes that this is sometimes called mixed or merged reality.

History of augmented reality

The foundations were laid in the early days of computer graphics. Ivan Sutherland’s 1968 paper “A head-mounted three dimensional display” is often cited as an ancestor of both augmented and virtual reality, because it showed that a headset could draw computer graphics that responded to where the wearer looked.

The phrase itself came later. In 1992, Thomas Caudell and David Mizell of Boeing presented a paper titled “Augmented reality: an application of heads-up display technology to manual manufacturing processes” at the Hawaii International Conference on System Sciences. An EBSCO overview credits their work on a see-through head-mounted display in the 1990s with the origin of the term.

In 1997, the researcher Ronald Azuma published “A Survey of Augmented Reality” in the journal Presence. His widely used description says that an AR system combines real and virtual content, is interactive in real time and registers the two with each other in three dimensions. Registration, meaning keeping a virtual object aligned with the right spot in the real world, remains one of the central technical problems.

AR reached the public in the 2010s. Google Glass, released in 2012, was one of the first AR devices aimed at ordinary consumers rather than gamers, though it was not a commercial success. The company Magic Leap, which Google funded, patented technology intended to beam images into a wearer’s retinas. In the early 2010s, advances let AR headsets shrink and graphics improve, and smartphone apps such as Snapchat and the game Pokemon Go later brought AR to a wide audience.

How augmented reality works

An AR system must do three things. It has to sense the real scene, usually with a camera and motion sensors, and work out where the device is and what it is looking at. It then has to render digital content aligned with that view, and finally it must show the combination to the user quickly enough to feel natural. Software that analyzes camera images to recognize surfaces and objects draws on computer vision.

There are two main ways to display the result. On a phone, tablet or video headset, a camera shows the scene on a screen with graphics added. In see-through glasses, the wearer looks at the real world directly through transparent lenses while the digital layer is projected onto them. Either way, the display must keep the overlay steady as the user moves.

Types of augmented reality

The most common type is handheld AR, in which the camera and screen of a smartphone or tablet do the work. Head-worn AR uses glasses or headsets, such as Microsoft HoloLens, which EBSCO lists as an example of the technology. The FDA also names heads-up displays, which project information onto a transparent surface in the user’s line of sight. EBSCO notes that AR could eventually move into contact lenses and other small wearables.

Applications of augmented reality

Retailers use AR so shoppers can see how furniture would look in their rooms, and mobile apps use it to point out nearby banks, restaurants and landmarks and to share information about local places and events. In education, it can show medical students a three-dimensional model of a human heart. In manufacturing, where Caudell and Mizell began, it can guide workers through assembly tasks by displaying instructions on the work itself.

The FDA maintains a list of AR and VR medical devices authorized for marketing in the United States. Devices on it have gone through the agency’s premarket review of safety and effectiveness. The agency says these technologies can help patients and clinicians prepare for or carry out certain treatments or procedures, and may make it easier for patients to complete treatment and monitoring routines.

Advantages and disadvantages of augmented reality

The core advantage is that AR adds information without taking the user out of their surroundings. People continue to recognize the real scene and receive extra context, which can speed up learning and tasks. Smartphone AR needs no special hardware beyond a device many people already own. Large technology companies including Google, Apple and Microsoft have invested heavily, and partnerships with eyewear brands have produced smart glasses that combine vision correction with audio features and smart home control.

The disadvantages are practical. Head-worn devices can be costly, bulky or tiring, and Google Glass showed that consumers may reject a design even when the technology works. Keeping digital objects precisely registered to the real world is hard in changing light and on moving subjects. In health care, benefits must be demonstrated through the same safety and effectiveness reviews as other medical devices.

Augmented reality vs. virtual reality

Augmented reality builds on the real world, and virtual reality replaces it. In AR, users see their surroundings and the digital layer together. In VR, the headset blocks the real view and shows a simulated environment. The overlap between them is substantial, since both rely on tracking, graphics and display technology, and some devices combine the two.

Editorially reviewed by Specialty Digest Editorial TeamLast reviewed November 4, 2026Researched and drafted with AI assistanceReport an issue