What goes into making smart glasses
Smart glasses put a battery, a Bluetooth or Wi-Fi system-on-chip, microphones and small open-ear speakers into the temples of a spectacle frame, and may add a camera at the hinge or bridge and a display engine with a waveguide or combiner in front of the eye. Manufacturing them combines eyewear frame production, lens supply, miniature electronics assembly and, for display glasses, optical alignment that most consumer electronics lines never do.
The difficulty comes from weight, space and the hinge. A temple may be only a few millimeters thick, users notice small changes in weight and balance, and the electronics in the temples usually connect through the front frame and across hinges that open and close thousands of times. Fit across different head and nose shapes, prescription support, skin temperature, and lens and eye-safety rules all add requirements a phone accessory never has. The first decision is which kind of smart glasses you are building, because each has a different supply chain.
Three product types, three supply chains
| Type | What is inside | What it means for manufacturing |
|---|---|---|
| Audio glasses | Speakers, microphones, battery, BLE chip, touch or button controls | Closest to earbuds in an eyewear frame; acoustic tuning, hinge wiring and frame styling are the main work |
| Camera glasses | Audio parts plus an image sensor module, more compute, storage, Wi-Fi and a recording indicator light | More heat and power, camera alignment and calibration, and privacy expectations around the indicator |
| Display or AR glasses | A display engine (micro-OLED, LCoS, microLED or laser scanning), a waveguide or combiner, often tracking cameras and heavier compute | Optical alignment between engine and waveguide, binocular alignment between the two eyes, and a small supplier base for optics with yield-driven pricing |
A program can move between types over its life, but the frame architecture rarely survives the jump from audio to display. Plan the first product for what it is.
Architecture and sourcing considerations
Frame material. Injection-molded nylon and similar polyamides are common for electronic frames because cavities for batteries and boards can be molded in. Cellulose acetate, the traditional premium frame material, is milled from sheet and is harder to combine with embedded electronics. Metal frames such as titanium or stainless steel look premium but complicate antenna design and add weight.
Hinge and interconnect. Electronics in both temples need power and data paths through the front frame, or each temple runs on its own battery and the two sides communicate wirelessly. Flex circuits through the hinge are a known wear point. Spring hinges, flex routing and strain relief have to be designed together and tested for cycle life.
Battery. Thin, elongated custom cells shaped to the temple are typical, sometimes one in each temple to balance weight. Custom cells mean cell-maker qualification, safety reports for the exact cell and longer lead times.
Acoustics. Open-ear speakers trade loudness against sound leakage to people nearby. Microphone arrays for voice pickup need acoustic ports, meshes and membranes that also keep out sweat and rain.
Optics. Waveguides and display engines come from a small number of specialist suppliers. Capacity, yield and lead time can set the launch date, so qualify that supply before committing to a volume plan.
Heat. A processor and battery next to the temple can raise skin temperature. Safety standards such as IEC 62368-1 limit the temperature of surfaces in prolonged skin contact, so thermal design is a compliance question as well as a comfort one.
Core manufacturing processes
- Frame production: molding or milling, polishing, painting or coating, and color matching between front and temples that often come from different tools or materials
- Miniature PCB assembly: fine-pitch parts on rigid-flex boards shaped to the temple
- Hinge and flex assembly: routing flex circuits through the hinge with controlled bend radius and strain relief
- Acoustic assembly: speaker and microphone fitting with seals and meshes; many audio glasses target a splash rating such as IPX4
- Camera integration: the module maker focuses and aligns the lens; the glasses assembler aligns the module to the frame and calibrates it
- Display integration: aligning the display engine to the waveguide, bonding with UV-cure adhesive, and aligning left and right images to each other, usually in a clean environment because dust on optics is a visible defect
- Lens fitting: edging and mounting lenses, an optical-shop process that may sit with a separate supplier
Testing and validation: EVT, DVT and PVT
EVT tests the architecture: weight and center of gravity on real heads, antenna performance on a head phantom, skin temperature during typical use, audio tuning and, for display glasses, image quality and brightness in daylight.
DVT repeats the key measurements on frames and parts from production tooling, then adds durability and compliance testing:
- Hinge cycle tests with electrical continuity monitored throughout, not only checked at the end
- Temple flex, frame bending and drop tests
- Sweat, sunscreen and cosmetics exposure on coatings, paints and seals
- Temperature and humidity cycling, followed by checks of display alignment and camera calibration
- Lens impact testing where lens rules require it
- RF exposure assessment and formal radio testing
- Fit trials across head sizes and nose shapes, including low nose-bridge fits
PVT sets the limits and cycle times for end-of-line testing, which typically covers speaker frequency response and microphone sensitivity in an acoustic test box, touch controls, camera focus and calibration, display alignment and uniformity, radio, charging, hinge continuity and cosmetic inspection. If you offer prescription lenses, PVT also has to prove the order routing and fitting process, not only the hardware. Stage-gate criteria common to all products are in the EVT, DVT and PVT guide.
Certifications and rules by market
Smart glasses sit under two sets of rules: electronics and eyewear. Confirm the scope with a test lab and, for lenses, an eyewear regulatory specialist.
| Area | Typical requirements |
|---|---|
| Radio and EMC | FCC Part 15 in the US, CE under the Radio Equipment Directive in the EU (including its cybersecurity requirements for wearable radio equipment), UKCA or CE in Great Britain, and national approvals elsewhere |
| RF exposure | Assessment for a transmitter worn on the head; SAR testing unless an exemption applies |
| Electrical and battery safety | IEC 62368-1 for the product, IEC 62133-2 for the battery, UN 38.3 for shipping |
| Light sources | IEC 62471 photobiological safety for LED-based displays and indicators; IEC 60825-1 if a laser is used |
| Lenses and frames, US | FDA generally treats spectacle frames, prescription lenses and sunglasses as low-risk medical devices and requires impact-resistant lenses |
| Lenses and frames, EU | Sunglass lenses are typically covered by personal protective equipment rules and EN ISO 12312-1; prescription eyewear is regulated as a medical device |
Camera glasses also raise privacy expectations. A visible recording indicator that cannot be disabled in software is widely expected, and data handling in the companion app falls under privacy law in most markets.
What drives the cost
- Optics: for display glasses, the display engine and waveguide often dominate the bill of materials, and their price depends on supplier yield
- Frame styles and colors: each new frame shape is close to a new mechanical product, with its own tooling, fit testing and inventory
- Battery and acoustics: custom cells and acoustic parts for audio glasses
- Prescription program: lens supply, fitting labor and order handling
- Certification: RF exposure testing and eyewear compliance on top of radio and safety testing
- Yield: display alignment and hinge failures found late are expensive because the unit is fully assembled
What to ask an OEM/ODM partner
- Which eyewear products with electronics through the hinge have you put into production, and what did their hinge cycle tests show?
- Who makes the frame and who assembles the electronics, and who is responsible for the finished product?
- How do you align the display or camera, and how is alignment verified on every unit?
- How will weight and balance be tracked as the design changes?
- What waveguide or display-engine yield is assumed in your price, and what happens if it is lower?
- Who will handle prescription lenses, and how are those orders routed and checked?
Common mistakes
- Designing one frame for all faces, then discovering fit problems with nose bridges and head widths in one major market
- Underestimating how many frame styles the brand will want, and the tooling and inventory each one brings
- Adding prescription support after the frame is frozen
- Testing hinges for mechanical life but not for electrical continuity under motion
- Leaving skin temperature to the end, when the fix is a change in architecture
Where Zefinity helps
Most smart-glasses risk is set during product definition: which type you are building, how the frame carries the electronics and which optics supply you can depend on. Our Develop service reviews the PRD and architecture against what manufacturing partners can deliver, and gives access to engineering resources across the network before supplier selection starts. For other products in the category, see wearables.
Frequently asked questions
Can one factory make both the frames and the electronics for smart glasses?
Some can, but often the frame maker and the electronics assembler are different companies. Eyewear frame production, lens supply and miniature electronics assembly are separate specialties. What matters is that one party is clearly responsible for the finished product, including fit, hinge reliability and final test, and that the interfaces between suppliers are specified.
How do smart glasses handle prescription lenses?
Common approaches are prescription lenses edged and fitted by an optical lab into the frame, clip-in or magnetic prescription inserts, or, for display glasses, lenses bonded to or placed around the waveguide. Each route has its own supply chain, lead time and regulatory status, so decide which one you will offer before the frame design is frozen.
Do smart glasses need SAR testing?
Possibly. Because the radios sit next to the head, regulators expect an RF exposure assessment. Whether full SAR testing is required or an exemption applies depends on transmit power, frequency and separation from the body. Low-power Bluetooth designs sometimes qualify for exemption; Wi-Fi and cellular designs are more likely to need testing. A test lab can confirm early.