Reference

Smart Glasses Glossary

Common terms you’ll see across smart glasses coverage. 35 entries.

AI Assistant Integration: The ability to speak to an on-device or cloud-connected AI (like Meta AI or Google Gemini) directly through the glasses, using built-in microphones and speakers. This is a core feature differentiating current smart glasses from simple Bluetooth frames.
AR vs. Camera Glasses: AR glasses project a digital display overlay into your vision; camera glasses are essentially stylish frames with a camera, microphone, and speaker but no visual display. These are two very different product categories often confused under the 'smart glasses' label.
Birdbath Optics: An older, simpler optical design that uses a curved beam-splitter to redirect display light into your eye. Birdbath optics are cheaper to produce than waveguides but create thicker, heavier lenses and a noticeable reflection effect.
Charging Case: A protective case that also charges the glasses battery when stored inside, similar to true wireless earbud cases. A key accessory for camera and audio smart glasses since built-in battery life is typically only 3–6 hours.
Companion App: The smartphone app required to unlock full functionality of a pair of smart glasses — syncing media, configuring settings, and often acting as the display interface. A poor companion app can make great hardware frustrating to use.
Diffractive Waveguide: The most common waveguide type, which uses microscopic grating patterns etched into glass to steer light. It enables thin lenses but often causes rainbow artifacts and color washout compared to other methods.
Directional Speakers: Small speakers angled specifically toward the ear canal from a glasses arm, designed to focus sound and reduce how much leaks to bystanders. Build quality and speaker angle vary significantly across brands.
DoF (Degrees of Freedom): How many axes of head movement the glasses track. 3DoF tracks rotation only (looking around); 6DoF adds positional tracking (moving through space). Most consumer AR glasses are 3DoF, which limits AR content to locked-to-head overlays.
Electrochromic Dimming: A technology that lets the lenses electrically darken on demand, like smart tint, rather than reacting to UV like photochromic lenses. Rare but appearing in some AR glasses to manage ambient light hitting the display.
Eye Tracking: Sensors that detect exactly where you are looking within the display. Eye tracking enables more natural interaction and more efficient rendering (foveated rendering), but it's mostly absent in current consumer AR glasses and present mainly in prototypes like Meta Orion.
Field of View (FOV): The angle of the visible display area in AR glasses, measured in degrees. A wider FOV means more of your vision is covered by the virtual image — most consumer AR glasses today range from about 20° to 50°.
First-Person Camera: A camera mounted on the glasses frame that captures photos and video from roughly your eye-level perspective. Placement, resolution, and low-light performance vary widely and are key specs to compare when buying camera glasses.
Foveated Rendering: A rendering technique that draws the area you're directly looking at in full detail while reducing quality at the edges of your vision. It dramatically lowers processing load but requires accurate eye tracking to work — not yet available in mainstream consumer AR glasses.
Head Tracking: The glasses' ability to detect and respond to the direction and movement of your head. Good head tracking is required for AR content that appears anchored to the real world rather than floating in front of your face.
Hey Meta / Wake Word: The voice trigger phrase used to activate the AI assistant on Ray-Ban Meta glasses without touching them. All major AI-enabled glasses use a wake word; false triggers and wake-word latency are common real-world gripes.
Holographic Waveguide: A waveguide variant that uses recorded light patterns (holograms) rather than etched gratings to redirect display light. Tends to offer better color accuracy but is more expensive and rarer in consumer products.
IPD (Interpupillary Distance): The distance between the centers of your two pupils, measured in millimeters. For AR glasses with a display, IPD compatibility affects whether the image will be sharp and comfortable for your eyes — many consumer AR glasses have a fixed IPD that won't suit everyone.
Latency: The delay between an action (moving your head, issuing a voice command, receiving a notification) and the glasses responding. High latency makes AR overlays feel unreal and AI responses feel sluggish — important to check in reviews.
Luma Waveguide: A brightness metric sometimes used by manufacturers to specify how much light the waveguide delivers to the eye specifically, rather than the raw projector output. Harder to compare across brands because not all use the same measurement method.
Meta View App: The iPhone and Android companion app required to set up and use Ray-Ban Meta smart glasses. It manages photo/video sync, AI assistant settings, firmware updates, and music controls.
Micro-OLED: A tiny, high-resolution display chip used as the image source inside many AR glasses. Micro-OLED panels are brighter and more power-efficient than traditional miniature displays, making them popular in premium devices.
MicroLED: A next-generation display technology that uses microscopic individual LEDs per pixel, offering higher brightness and efficiency than Micro-OLED. Currently rare in consumer smart glasses but expected to appear in future products including Meta Orion.
Multimodal AI: An AI assistant capable of processing what the camera sees alongside what you say, so you can ask questions about objects or scenes in front of you. This vision-plus-voice capability is what separates current AI glasses from earlier Bluetooth audio frames.
Nebula: XREAL's companion app platform for managing AR display content, screen mirroring, and spatial window layouts. Available on Android and Mac; the software experience through Nebula significantly affects how useful XREAL glasses feel day-to-day.
Open-Ear Audio: Speakers built into the glasses frame that direct sound toward your ears without sealing them, so you stay aware of your surroundings. Sound quality is lower than earbuds and audio leaks to people nearby — a real trade-off to understand before buying.
Photochromic Lens: A lens that automatically darkens in sunlight and clears indoors by reacting to UV light. Some smart glasses offer photochromic lens options, but the tint can interfere with AR display visibility — an important trade-off to check.
Prescription Insert: A separate inner frame holding corrective lenses that clips inside smart glasses designed for people who need vision correction. Not all smart glasses support inserts, and fit and optical quality vary by brand.
RGB Camera vs. Infrared Camera: RGB cameras capture standard color photos and video; infrared cameras are used for eye-tracking, gesture detection, or depth sensing. Many AR glasses include both types for different functions, though only the RGB camera produces shareable images.
See-Through Display: A display that overlays digital content on top of your real-world view without blocking it, as opposed to a screen that replaces what you see. True see-through is the defining feature of AR glasses versus VR headsets.
Spatial Audio: Audio processing that makes sound appear to come from specific locations in 3D space around you. Some smart glasses apply spatial audio to media playback or navigation cues to feel more immersive or directionally useful.
Tethered vs. Standalone: Tethered AR glasses require a wired connection to a phone, dongle, or PC to render content; standalone glasses have their own onboard processor. Tethered devices are lighter but less convenient; standalone avoids cables but adds weight.
Touch Controls: Capacitive or physical tap areas built into the temple arms of smart glasses for play/pause, photo capture, volume, and assistant activation. How intuitive and reliable these are affects daily usability more than spec sheets suggest.
Waveguide: A thin optical component inside AR glasses that takes light from a projector and guides it across the lens to your eye. The technology behind waveguides largely determines image clarity, brightness, and how thick the lens needs to be.
Waveguide Brightness (Nits): How bright the projected image appears, measured in nits. AR glasses need high nit counts to remain visible in outdoor or well-lit environments — low brightness is one of the biggest real-world complaints.
XREAL Beam: A standalone Android-based compute dongle made by XREAL that plugs into XREAL Air glasses, adding a processor, app store access, and head-tracking without needing a phone or PC. A common accessory upgrade for XREAL users.