Here’s a new one: smart glasses. “Smart” this, “smart” that. Once “smart” described humans; now, products. The 21st century, awash with smart products, is the smartest century ever. Smart product history is traceable all the way back to 1867: a remotely controlled toy boat. That’s prehistory, really. History proper begins a century later (1968) with Echo IV, a proto home computer that could switch appliances on and off, write a household budget, control home temperature, regulate the kids’ TV access and so on. It was great science but bad marketing: too big, too awkward, it didn’t fit. It was a harbinger, not a hit. The hits of the 21st century were born in the late 20th. Astonishing at first, they are now commonplace. Novelty wears off quickly. The ubiquitous smartphone aside, there are smart cars, smart cards, smart locks, smart doorbells, smart refrigerators, smart saltshakers, smart just about anything. Embryonic smart glasses were Echo IV’s contemporaries, and shared its fate – their time was not yet. It’s now. Beware, warns Spa magazine (July 21-28). They’re dangerous. They range in price from 12,000 to 100,000 yen. The cheapest model displayed on Amazon offers “newest HD camera and speaker, 200 W image stabilization camera glass, video recording, dual microphone, video/ photography, automatic transmission, ENC call noise reduction, audio recording, real-time translation, AI voice assistant, AI image recognition, camera, music player, video recording” – one very smart pair of spectacles! They join the growing ranks of wearable technology – rings, watches, shirts, socks, jackets, trousers – that count, measure and/ or compute steps, heart rate, breathing, sleep, body temperature, foot pressure – everything countable, measurable and computable, and no doubt we’re the healthier for it, though one might venture the suggestion that there are enough things to worry about without all this data