ON A recent visit to Silicon Valley, an unauthorised tour of the Google campus resulted in an unexpected discovery. Google allows visitors to walk around its Googleplex grounds but not to enter its buildings. That way it seems like part of the broader community, but no one can stumble upon projects under development or under wraps.

So it was with some surprise that I bumped into a troop of Google employees all wearing the latest innovation from the search giant, a “wearable computer” called Google Glass. It looks like a pair of spectacles — but as worn by a character from Star Trek or X-Men.

The Nooglers — new employees at Google, typically given the most menial tasks — said they were working in shifts, testing the glasses in all conditions, around the clock. Stress-testing on this scale is often one of the final steps before a product is released commercially, so we can expect to see Google Glass on shelves in the coming months.

It has been described in breathless terms as “the next paradigm”, a revolution in photography and the future of eye wear. Some have even suggested it is a solution for the elderly who cannot get their heads around computers. I can just see that argument convincing my 91-year-old mother to wear yet another age-aid.

Some argue, though, that it is the logical next step from wearing Bluetooth earpieces that link wirelessly to a phone or music player. For business, it means an additional interface that can be used to access information during meetings or out of the office.

In truth, it makes the user look like a 20th-century watchmaker and turns anyone in the vicinity of the user into a privacy-obsessed paranoiac. Because it includes a built-in camera — for video and stills — as well as facial-recognition technology, it is regarded as the ultimate tool for the invasion of privacy. Aside from allowing the user to record scenes unobtrusively, the device can be asked to identify anyone in a public space and run a search on the person.

It remains to be seen how effective it will be for such “real-time” use, but the promise — or threat — is enough to get privacy activists hot under the ID.

Other features are equally exciting and threatening. The device responds to voice commands, and a touchpad on the side allows swiping through content being viewed by the wearer on a transparent display.

It has already been banned by casinos, which see it as the ultimate card-counting and cheating device. Hospitals have banned it because of concerns for patient privacy and dignity. Cinemas are expected to ban it to avoid the recording of movies.

But Time magazine points out that the response is very similar to the furore that met the first Kodak camera in 1888: it was banned from beaches in case someone took a photo of a female sunbather in a (gasp) 19th-century swimsuit.

The current version, called the Explorer, has gone out to 8,000 developers and consumers who will test and create applications for it. But the next step, when it reaches the general market, will be the true test. The real question the market will ask is unlikely to be: “Which version of Android does it run?” More likely, people will want to know: “Do I look ridiculous in this?” The answer, for the most part, will be “Yes”.

• This article was first published in Sunday Times: Business Times