Smart sunglasses which are programmed to change tint by electronic means are an example of the latter type of smartglasses.[4] Superimposing information onto a field of view is achieved through an optical head-mounted display (OHMD) or embedded wireless 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.[5][6][7][8][9]