Augmented reality (AR), also known as mixed reality (MR), is a form of 3D human–computer interaction that overlays real-time 3D-rendered computer graphics into the real world through a display, such as a handheld device or head-mounted display. This experience is seamlessly interwoven with the physical world such that it is perceived as an immersive aspect of the real environment. In this way, augmented reality alters one's ongoing perception of a real-world environment, compared to virtual reality, which aims to completely replace the user's real-world environment with a simulated one.Steuer,, Department of Communication, Stanford University. 15 October 1993.Introducing Virtual Environments National Center for Supercomputing Applications, University of Illinois. Augmented reality is typically visual, but can span multiple sensory modalities, including auditory, haptic, and somatosensory.
The earliest functional AR systems that provided immersive mixed reality experiences for users were invented in the early 1990s, starting with the Virtual Fixtures system developed at the U.S. Air Force's Armstrong Laboratory in 1992. Commercial augmented reality experiences were first introduced in entertainment and gaming businesses. Subsequently, augmented reality applications have spanned industries such as education, communications, medicine, and entertainment.
Augmented reality frameworks include ARKit and ARCore. Commercial augmented reality headsets include the Magic Leap 1 and HoloLens. A number of companies have promoted the concept of smartglasses that have augmented reality capability.
Augmented reality refers to experiences that are artificial and that add to the already existing reality. In AR, information about the environment and its objects can be overlaid on the real world. This information can be virtual or real, e.g. seeing other real sensed or measured information such as electromagnetic radio waves overlaid in exact alignment with where they actually are in space.Time-frequency perspectives, with applications, in Advances in Machine Vision, Strategies and Applications, World Scientific Series in Computer Science: Volume 32, C Archibald and Emil Petriu, Cover + pp 99–128, 1992. Augmented reality also has a lot of potential in the gathering and sharing of tacit knowledge.
Augmented reality can be defined as a system that incorporates three basic features: a combination of real and virtual worlds, real-time interaction, and accurate 3D registration of virtual and real objects. The overlaid sensory information can be constructive (i.e. additive to the natural environment), or destructive (i.e. masking of the natural environment).
Hardware and displays
AR visuals appear on handheld devices (video passthrough) or head-mounted displays (optical see-through or video passthrough). Systems pair a display with sensors (e.g., cameras and IMUs) to register virtual content to the environment; research also explores near-eye optics, projection-based AR, and experimental concepts such as contact-lens or retinal-scanned displays.
Head-mounted displays
AR HMDs place virtual imagery in the user's view using optical see-through or video passthrough and track head motion for stable registration.
Handheld Phone and tablet AR uses the rear camera (video passthrough) plus on-device SLAM/VIO for tracking.
Projection mapping
Projectors overlay graphics onto real objects/environments without head-worn displays (spatial AR).
AR glasses Glasses-style near-eye displays aim for lighter, hands-free AR; approaches vary in optics, tracking, and power.
3D tracking
AR systems estimate device pose and scene geometry so virtual graphics stay aligned with the real world. Common approaches include visual–inertial odometry and SLAM for markerless tracking, and fiducial markers when known patterns are available; image registration and depth cues (e.g., occlusion, shadows) maintain realism.
Software and standards
AR runtimes provide sensing, tracking, and rendering pipelines; mobile platforms expose SDKs with camera access and spatial tracking. Interchange/geospatial formats such as ARML standardize anchors and content.
Interaction and input
Input commonly combines head/gaze with touch, controllers, voice, or hand tracking; audio and haptics can reduce visual load. Human-factors studies report performance benefits but also workload and safety trade-offs depending on task and context.
Design considerations Key usability factors include stable registration, legible contrast under varied lighting, and low motion-to-photon latency. Visual design often uses depth cues (occlusion, shadows) to support spatial judgment; safety-critical uses emphasize glanceable prompts and minimal interaction.
Comparison with mixed reality/virtual reality Augmented reality (AR) is largely synonymous with mixed reality (MR). There is also overlap in terminology with extended reality and computer-mediated reality. However, In the 2020s, the differences between AR and MR began to be emphasized.Rokhsaritalemi, S., Sadeghi-Niaraki, A., & Choi, S. M. (2020). A review on mixed reality: Current trends, challenges and prospects. Applied Sciences, 10(2), 636.Buhalis, D., & Karatay, N. (2022). Mixed reality (MR) for generation Z in cultural heritage tourism towards metaverse. In Information and communication technologies in tourism 2022: Proceedings of the ENTER 2022 eTourism conference, January 11–14, 2022 (pp. 16-27). Springer International Publishing.
In augmented reality, users are not only able to view digital content within their real environment but can also interact with it as if it were a tangible part of the physical world. This is made possible through devices such as Meta Quest 3S and Apple Vision Pro, which utilize multiple cameras and sensors to enable real-time interaction between virtual and physical elements. Mixed reality that incorporates haptics has sometimes been referred to as visuo-haptic mixed reality.
In virtual reality (VR), the users' perception is completely computer-generated, whereas with augmented reality (AR), it is partially generated and partially from the real world. For example, in architecture, VR can be used to create a walk-through simulation of the inside of a new building; and AR can be used to show a building's structures and systems super-imposed on a real-life view. Another example is through the use of utility applications. Some AR applications, such as Augment, enable users to apply digital objects into real environments, allowing businesses to use augmented reality devices as a way to preview their products in the real world. Similarly, it can also be used to demo what products may look like in an environment for customers, as demonstrated by companies such as Mountain Equipment Co-op or Lowe's who use augmented reality to allow customers to preview what their products might look like at home.
Augmented reality (AR) differs from virtual reality (VR) in the sense that in AR, the surrounding environment is real and AR is just adding virtual objects to the real environment. On the other hand, in VR, the surrounding environment is completely virtual and computer generated. A demonstration of how AR layers objects onto the real world can be seen with augmented reality games. WallaMe is an augmented reality game application that allows users to hide messages in real environments, utilizing geolocation technology in order to enable users to hide messages wherever they may wish in the world.
The use of the terms "mixed reality" and "interreality" is clearly defined in the context of physics and may be slightly different in other fields, however, it is generally seen as, "bridging the physical and virtual world".Repetto, C. and Riva, G., 2020. From Virtual Reality To Interreality In The Treatment Of Anxiety Disorders. [online] Jneuropsychiatry.org. Available at: https://www.jneuropsychiatry.org/peer-review/from-virtual-reality-to-interreality-in-the-treatment-of-anxiety-disorders-neuropsychiatry.pdf [Accessed 30 October 2020].
Recent improvements in AR and VR headsets have made the display quality, field of view, and motion tracking more accurate, which makes augmented experiences more immersive. Improvements in sensor calibration, lightweight optics, and wireless connectivity have also made it easier for users to move around and be comfortable.
History
Precursors to augmented reality 1901: Author L. Frank Baum, in his science-fiction novel The Master Key, first mentions the idea of an electronic display/spectacles that overlays data onto real life (in this case 'people'). It is named a 'character marker'.Johnson, Joel. "The Master Key": L. Frank Baum envisions augmented reality glasses in 1901 Mote & Beam 10 September 2012. Heads-up displays (HUDs), a precursor technology to augmented reality, were first developed for pilots in the 1950s, projecting simple flight data into their line of sight, thereby enabling them to keep their "heads up" and not look down at the instruments. It is a transparent display.
Earliest developments 1968: Ivan Sutherland creates the first optical-see through head-mounted display that has graphics rendered by a computer. 1975: Myron Krueger creates Videoplace to allow users to interact with virtual objects. 1980: The research by Gavan Lintern of the University of Illinois is the first published work to show the value of a heads up display for teaching real-world flight skills. 1980: Steve Mann creates the first wearable computer, a computer vision system with text and graphical overlays on a photographically mediated scene. 1986: Within IBM, Ron Feigenblatt describes the most widely experienced form of AR today (viz. "magic window," e.g. smartphone-based Pokémon Go), use of a small, "smart" flat panel display positioned and oriented by hand. (context & abstract only) IBM Technical Disclosure Bulletin 1 March 1987 (image of anonymous printed article) IBM Technical Disclosure Bulletin 1 March 1987 1987: Douglas George and Robert Morris create a working prototype of an astronomical telescope-based "heads-up display" system (a precursor concept to augmented reality) which superimposed in the telescope eyepiece, over the actual sky images, multi-intensity star, and celestial body images, and other relevant information. 1988: David Drascic, Paul Milgram, and Julius Grodski demonstrate their working prototype of an interactive stereoscopic video system with superimposed stereoscopic graphics, which allows the user to select points in the video view for path planning, target acquisition, or measurement with a "virtual tape-measure". 1990: The term augmented reality is attributed to Thomas P. Caudell, a former Boeing researcher. 1992: Louis Rosenberg developed one of the first functioning AR systems, called Virtual Fixtures, at the United States Air Force Research Laboratory—Armstrong, that demonstrated benefit to human perception.Louis B. Rosenberg. "The Use of Virtual Fixtures As Perceptual Overlays to Enhance Operator Performance in Remote Environments." Technical Report AL-TR-0089, USAF Armstrong Laboratory (AFRL), Wright-Patterson AFB OH, 1992. 1992: Steven Feiner, Blair MacIntyre and Doree Seligmann present an early paper on an AR system prototype, KARMA, at the Graphics Interface conference. 1993: George Fitzmaurice created the first handheld spatially aware display for providing virtual and augmented experiences. 1993: Mike Abernathy, et al., report the first use of augmented reality in identifying space debris using Rockwell WorldView by overlaying satellite geographic trajectories on live telescope video. 1993: A widely cited version of the paper above is published in Communications of the ACM – Special issue on computer augmented environments, edited by Pierre Wellner, Wendy Mackay, and Rich Gold.