Smart glasses are going mainstream: a plain-English guide to AR, MR, XR, IPD, and more
Smart glasses are slowly becoming a part of everyday life, from Meta Ray-Bans to the upcoming Samsung Intelligent Eyewear. The category is expanding to include XR and display glasses like Xreal's Project Aura or the Viture Pro 2. With so many different devices, manufacturers are throwing around a flurry of terms — spatial computing, IPD, DoF — that explain what these glasses do, but in a clunky way that leaves many people confused.
Here's a breakdown of the core terms that explain most smart glasses in plain English, especially as they become more popular and available.
**The Three Realities: AR, MR, and XR**
If you look at the best smart glasses, the tech can be roughly divided into two categories: AI glasses and AR glasses. They do different things, but first, let's talk about realities. Digital content can be overlaid on the physical world in four ways: AR, MR, VR, and XR. VR (virtual reality) is what you get with headsets like the Meta Quest 3s, and for smart glasses, we'll focus on the other three.
XR (extended reality) is the umbrella term for all technologies that blend the physical and digital worlds. AR (augmented reality) overlays digital elements onto the real world, but they don't interact with it. MR (mixed reality) allows digital objects to be "anchored" in space and react to the environment. Examples: Apple Vision Pro (MR) and Meta Ray-Ban (AR).
**Spatial Computing and Tracking**
Spatial computing is the device's ability to understand its physical surroundings and the user's position within them. This is achieved through tracking: three degrees of freedom (3DoF) — head rotation, and six degrees of freedom (6DoF) — rotation plus movement in space. 6DoF provides full immersion, as in the Apple Vision Pro.
**Displays and Optics**
Most AR glasses use projection displays, where a microdisplay projects an image through a lens into your eye. Key parameters: field of view (FoV) — wider is better, and resolution per eye. Brightness (measured in nits) and refresh rate (in hertz) are also important. Interpupillary distance (IPD) — the distance between the centers of your pupils — must match the glasses' settings. Depth of field (DoF) is the range where the image remains sharp.
**Weight and Battery Life**
The weight of the glasses (in grams) is critical for comfort during long wear. Battery life (in hours) and charging method (USB-C or wireless) are practical considerations. Some models require connection to an external unit or smartphone.
**Audio and Cameras**
Built-in speakers and microphones provide sound and voice control. Cameras are used for photos, video, tracking, and object recognition. Pay attention to sensor quality and camera field of view.
**AI Glasses and the Future**
AI glasses (like Meta Ray-Ban) are a subset of AR glasses where the main function is a voice assistant with AI access, rather than visual overlay. They are lighter, cheaper, and have longer battery life, but don't offer full AR experiences. The future likely belongs to hybrid models combining AI and full AR capabilities.
