This paper surveys the field of Augmented Reality (AR), which integrates 3-D virtual objects into a 3-D real environment in real time. It describes applications in medical, manufacturing, visualization, path planning, entertainment, and military fields. The paper discusses the characteristics of AR systems, including tradeoffs between optical and video blending approaches. Registration and sensing errors are major challenges in building effective AR systems, and current efforts to overcome these are summarized. Future directions and areas requiring further research are also discussed. The paper defines AR as systems that combine real and virtual, are interactive in real time, and are 3-D registered. It describes six classes of potential applications, including medical visualization, maintenance and repair, annotation, robot path planning, entertainment, and military aircraft navigation. The paper also discusses the characteristics of AR systems, comparing them with Virtual Environments (VE). It highlights the differences between optical and video approaches, focusing on factors such as simplicity, resolution, safety, and eye offset. The paper also addresses issues such as focus and contrast, portability, and the importance of accurate registration. Registration errors are a major problem in AR, and the paper discusses static and dynamic errors, along with methods to reduce them. The paper concludes that AR has significant potential in various fields, but challenges remain in achieving accurate registration and real-time interaction.This paper surveys the field of Augmented Reality (AR), which integrates 3-D virtual objects into a 3-D real environment in real time. It describes applications in medical, manufacturing, visualization, path planning, entertainment, and military fields. The paper discusses the characteristics of AR systems, including tradeoffs between optical and video blending approaches. Registration and sensing errors are major challenges in building effective AR systems, and current efforts to overcome these are summarized. Future directions and areas requiring further research are also discussed. The paper defines AR as systems that combine real and virtual, are interactive in real time, and are 3-D registered. It describes six classes of potential applications, including medical visualization, maintenance and repair, annotation, robot path planning, entertainment, and military aircraft navigation. The paper also discusses the characteristics of AR systems, comparing them with Virtual Environments (VE). It highlights the differences between optical and video approaches, focusing on factors such as simplicity, resolution, safety, and eye offset. The paper also addresses issues such as focus and contrast, portability, and the importance of accurate registration. Registration errors are a major problem in AR, and the paper discusses static and dynamic errors, along with methods to reduce them. The paper concludes that AR has significant potential in various fields, but challenges remain in achieving accurate registration and real-time interaction.