In the first article in this series, I used a simple framework: to become a mass-market product, a wearable AI device must solve three problems—socially acceptable design, truly useful AI, and viable hardware.

Headphones solved all three. Glasses solved two out of three—held back by the physics of video streaming. The conclusion was clear: until physics changes, headphones will win the mass market.

This time, I'll complete the picture. Spoiler: the conclusion remains the same. Only the limitations that block each alternative have changed.

Approximately 200 million smartwatches sold in 2025. The most popular wearable in the world.

Yet the smartwatch has not completely solved any of the three problems.

Design. Apple has normalized the rectangle on the wrist — Hermès straps, titanium case, special editions. But the Apple Watch is still perceived as technology, not as an object. A Rolex is handed down. An Apple Watch becomes obsolete in three years and needs to be recharged every night. This is not a criticism: it is a structural difference that weighs on adoption among those who consider the watch an identity accessory rather than a tool.

AI. watchOS 26 brought Apple Intelligence to the watch for the first time: Workout Buddy, notification summaries, Smart Focus mode. But for any heavier AI tasks — conversations with Siri, multimodal analysis — the Apple Watch depends on a nearby iPhone. Apple itself specifies this: “requires an Apple Intelligence-supported iPhone nearby.” The same offload architecture that works perfectly for headphones (light text via Bluetooth) does not scale well for a screen that wants to display visual information.

Hardware. The screen is too small to be a true AI interface. Talking to your wrist in public remains socially awkward. The battery lasts 18-36 hours — daily charging is mandatory. Adding a camera (Apple is working on it, patents have been filed) would require additional power — bringing us back to the unresolved trade-off of glasses.

If we apply the same framework systematically, the comparison becomes clear:

Where it really excels is as a smart medical device on your wrist: high blood pressure detection, ECG, continuous sleep monitoring. 2026 will bring advanced blood pressure monitoring and more sensors. But “smart medical device” is a different category from “pocket AI assistant.” The former is winning. The latter is not.

The smartwatch already knows more about you than you do. It knows the quality of your sleep, your stress level, your blood pressure. The paradox is that with all this knowledge, it still can't tell you anything useful without relying on the iPhone in your pocket. It's the most informed device in its category—and still the least autonomous.

If the smartwatch tries to do too much in too little space, the rings choose the opposite strategy: doing almost nothing.

Oura has sold over 5.5 million rings. Samsung has entered the market.

The approach is rational: if you can't have a screen, speaker, and heavy AI in a tiny space, remove everything. Only sensing remains. Oura has a battery life of 8 days. It is discreet, comfortable, and wearable 24/7. The AI infers readiness score, sleep quality, HRV, and menstrual cycle.

But applying the framework, rings cannot beat headphones because they are not playing the same game.

It's not a difference in performance—it's a difference in paradigm. And above all, the smartwatch already does everything the ring does, adding a screen and interaction. If you already have an Apple Watch Series 11, the ring becomes redundant.

The market is confirming this: Samsung has effectively frozen the Galaxy Ring 2, blocked by a patent war with Oura. Rings are growing much more slowly than glasses and remain a tiny fraction of the wearable market. They are a useful niche — not a platform.

If the problem with glasses is transmitting video via Bluetooth, contact lenses take the same problem to the extreme—less space, less battery power, and the additional constraint of being in contact with the eye tissue.

The reason is always the same: energy. The eyeball does not dissipate heat like the skin. The battery must be microscopic. And for real visual AI processing, an external device would still be needed — replicating the problem of glasses in an even more constrained version. The historic leader in the sector, Mojo Vision, discovered this at its own expense.

Smart contact lenses will probably arrive. First as medical devices (augmented correction, intraocular pressure monitoring, support for the visually impaired), then as AR displays. But not as mass AI assistants in the near future.

Black Mirror imagined it as a dystopia. Neuralink is building it as a therapy.

The chip in the brain is the only device that would truly solve the problem of input and output without a screen, speaker, or camera. The results for medical applications — cursor control with thought, communication for patients with ALS — are extraordinary.

But here the constraint is not physical. It is anthropological.

No regulator will approve a brain implant for consumer use in the next decade. No mass user will undergo neurosurgery to get faster Siri. The cost, risk, invasiveness, stigma — these are not engineering problems that can be solved with more efficient chips.

This is the real boundary of the wearable AI trajectory: there is no linear continuum from headphones to glasses to lenses to BCIs. There is a qualitative leap in acceptance that separates external devices from any implant. That leap will not be bridged with time — at least not with the time frame of a normal technology cycle.

Physics votes for headphones. Human biology votes even louder.

The complete picture

After two articles, the pattern is consistent:

🎧 Headphones → 3 problems solved out of 3. Mass market today. 420 million TWS units per year.

👓 Lightweight glasses → 2 problems solved out of 3. Early adopters today, mass market when physics unlocks. Meta dominates with ~70% market share.

⌚ Smartwatches → Excellent as a medical device on the wrist. Not as a general AI assistant. The gap will narrow, but it won't disappear anytime soon.

💍 Rings → Useful niche for those who don't want a smartwatch. Not a scalable platform.

👁️ Contact lenses → Medical research, not a consumer product in the short term.

🧠 BCI → Extraordinary medical transformation. Consumer technology: decades, not years.

Watching how Apple, Meta, and Samsung move says more than any market analysis. Apple has chosen the present: headphones, health, closed ecosystem. Meta has chosen the future: glasses, brand, global distribution with EssilorLuxottica. Samsung is trying to choose everything — and in wearables, as is often the case, those who don't choose end up winning nothing. The hierarchy of form factors is not just a technical fact. It is a strategic compass. And those who ignore it pay the price.

Every time a new form factor emerges, the question remains the same: how many problems does it solve, and what physics — or what human limitation — must still give way in order to solve them all?

For headphones, that physics has already given way. For everything else, we are still waiting.

Main sources

Fabio Lauria
CEO & Founder, ELECTE

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