## 1 Introduction  
Long life expectancies and dropping birth rates have resulted in changes in world demographics over the past two decades [1]. Coupled with this change in demographics, the past decades have witnessed a substantial increase in the use of technology in all aspects of daily living. Various studies are being conducted and thousands of new technologies are being developed to remedy issues that older adults might experience regarding physical and mental abilities, and eventually improve their quality of life [2, 3]. Recently, as an alternative technology for older adults, positive technology has emerged and is receiving attention. Positive technology ultimately aims to improve the overall quality of life by promoting human wellbeing, satisfaction, and contentment, rather than only focusing on device usability [4]. [PERSON] et al. [4] classify the positive technologies affecting human wellbeing into three aspects--physical, emotional, and social levels--and provide a comprehensive overview of the positive technological progress. [PERSON] et al. [5] explore the application of ambient intelligent (AmI) systems in the health care domain from various perspectives. They believe that AmI systems have the potential to facilitate individuals in leading a healthier lifestyle and to enhance physical wellbeing. Their study deals with challenges of AmI and research directions. Concern about the impact of long-term exposure to an environment in which many sensors are embedded, security or infrastructure issues, and social and ethical issues are introduced as the challenges AmI should overcome. [PERSON] et al. [6] present the potential benefits of research in affective computing (AC). AC in their study investigates the relationship between human emotions and computers, which has a positive impact on social, cognitive, physical, and other human behaviors. This study also reviews the general state of the art in AC applications in the health care domain. [PERSON] et al. [7] conduct a review on the way in which a robot understands the natural interaction between people and responds to that correctly from various perspectives. [PERSON] et al. [8] review the potential user's needs and expectations as regards a robot's help in relation to the independence of older adults and improvement of health outcomes. Using robots has been proposed as a way to support physical, social, and emotional wellness. However, despite the significant potential of AR and VR technologies to improve the quality of life of older adults, and their emergence as new technologies, very few papers review AR and VR studies on older adults and the literature on this topic is thus insufficient. Augmented reality (AR) and virtual reality (VR) technologies have been rapidly employed in a range of contexts, including gaming, navigation, medicine, education, and design [9; 10], [PERSON] et al. [11] collected all the articles about VR and AR in the Web of Science Core Collection scientific database. They conducted a computational analysis to show the evolution and development of VR and AR research over time [11]. According to Zion Market Research [12], by 2021, the AR market size will exceed US $133.78 billion and that of VR is expected to reach $75 billion. Thus, compared with the VR market, the AR market would grow much more rapidly; however, the VR market would also tend to increase steadily. AR combines virtual information with information on the physical environment on a real-time basis [9; 13]. VR technology delivers computer-generated simulations of 3D virtual environments that users experience by wearing a VR headset [10]. The main difference between the two is that AR integrates the virtual and real worlds, while VR offers complete immersion into a simulated environment and is entirely digitized. AR and VR are typically associated with younger populations, since these are sophisticated technologies, perceived as most suited for gaming platforms, and have characteristics such as being complex to set up and use.