How Do Smart Glasses Work? The Hardware, Piece by Piece

The camera

A camera module the size of a shirt button sits in a corner of the frame front: a 12-megapixel sensor behind a fixed-focus ultra-wide lens with roughly a 100-degree field of view (122 degrees and centered on the Vanguard). It shoots 3024 × 4032 stills, portrait only, and video at up to 3K/30 or 1080p/60 with electronic stabilization (Android Central, UploadVR). A white LED in the opposite corner blinks whenever it captures; Meta says the light has no off switch and the camera disables itself if the LED is covered. The camera quality page covers what the footage looks like.

Microphones and speakers

Five microphones on Meta's glasses — two in each arm and one near the nose pad (Android Central) — do three jobs: pick up your voice for calls and “Hey Meta,” cancel wind and background noise on calls, and capture audio for video. Two speakers, one in each temple just above the ear, play sound down into the ear canal without sealing it. Wikipedia's account of the original engineering describes micro-speakers, a multi-microphone array, an optimized Snapdragon, a capacitive touchpad and a battery all miniaturized to fit the frame — which is why the temples are thick.

Processor, storage and controls

A Qualcomm Snapdragon AR1 Gen 1 chip (Wikipedia) handles capture, stabilization and the audio; 32 GB of storage holds clips until they transfer. A touchpad on the right temple handles volume, play/pause and skip; a capture button takes photos and video; Meta's own-brand frames and the Vanguard add a customizable action button (Android Central, 9to5Google). Leaked reports point to a faster AR1+ chip in the next generation (TechRadar, Engadget); we report that as a report.

Battery and case

The battery is sealed inside the temples — no user replacement — and rated up to 8 hours of mixed use on Gen 2, or 5 hours of continuous audio; heavy use (music plus 3K video plus AI) measured about 20% per hour in Android Central's review. The charging case is the other half of the system: it carries about 48 hours of additional charge on Gen 2 (40 on Meta's own frames, 36 on the Vanguard) and tops the glasses up to 50% in 20 minutes. Echo Frames charge on a stand instead of a case; the Even G2's case holds seven charges.

The phone connection

The AI

“Hey Meta” wakes the assistant; the glasses send your speech — and, if you asked about what you see, a photo — to the phone and on to Meta's servers, and read the answer back through the speakers. Live translation works the same way, with Meta adding offline language packs by update (Android Central). Voice recordings are stored in Meta's cloud by default (TechCrunch), which is the part of “how they work” that the privacy settings page exists for.

How display glasses add a screen

A tiny projector in the temple shines an image into the edge of a waveguide — a lens with microscopic structures that bounce the light across and out toward your eye. The Even G2 uses green microLED projectors into both lenses for a 27.5-degree text display at 1,200 nits (AR Compare); the Meta Ray-Ban Display puts a 20-degree color display in the right lens only (Android Central). Because the light exits toward your eye, nobody else can see it. The trade is thickness, weight, prescription complexity (the Display's lenses are fused to the waveguide) and, on the Meta pair, a wrist band to control it without touching your face.