Wikipedia
Smartglasses or smart glasses or Digital Eye Glass or Personal Imaging System are a wearable computer that adds information to what the wearer sees. Typically this is achieved through an optical head-mounted display (OHMD) or computerized internet-connected glasses with transparent heads-up display (HUD) or augmented reality (AR) overlay that has the capability of reflecting projected digital images as well as allowing the user to see through it, or see better with it. While early models can perform basic tasks, such as just serve as a front end display for a remote system, as in the case of smartglasses utilizing cellular technology or Wi-Fi, modern smart glasses are effectively wearable computers which can run self-contained mobile apps. Some are handsfree that can communicate with the Internet via natural language voice commands, while other use touch buttons.
Like other computers, smartglasses may collect information from internal or external sensors. It may control, or retrieve data from, other instruments or computers. It may support wireless technologies like Bluetooth, Wi-Fi, and GPS. While a smaller number of models run a mobile operating system and function as portable media players to send audio and video files to the user via a Bluetooth or WiFi headset. Some smartglasses models, also feature full lifelogging and activity tracker capability.
Such smartglasses devices may also have all the features of a smartphone. Some also have activity tracker functionality features (also known as "fitness tracker") as seen in some GPS watches.