The Apple rumour mill is spinning with gossip that the company is reportedly developing and testing a set of augmented reality glasses. There's little we know for certain about the plans, and the firm has reportedly not made a final decision about whether to commit to releasing a "smart glasses" product. But Apple has been enthusiastically recruiting engineers with expertise in both augmented and virtual reality.
There is strong speculation that any new wearable device from Apple will integrate with an iPhone and need one to operate, just as the Apple Watch does. Another rumour suggests Apple will add augmented reality capabilities to its iPhone camera so that it could recognise objects it filmed, including people's faces. This raises the question of whether Apple would develop an additional wearable device that risked cannibalising a technology built into its flagship product.
But if the rumours of Apple's smart glasses are true, there is plenty the company could learn from previous, largely unsuccessful attempts to make a head-mounted augmented reality display. When Google announced it was ceasing sales of its own Google Glass spectacles, some saw it as the start of a new phase of product development while others pronounced it a failure.
Some of the key reasons why Glass was ultimately unsuccessful related to concerns about privacy and security. And there is little or no evidence those concerns have lessened in the last few years. With increasing numbers of reports about cameras being hijacked by hackers, fraudsters and even blackmailers, any new smart glasses could be seen as a window into our world for criminals.
There would certainly be doubts about giving a corporation direct access to what we see with our own eyes. Trust will be a key issue, and is still low between corporations and the public. As even the iPhone is no longer the legendary unhackable device it was once seen as, Apple would need to fundamentally boost consumer trust and confidence for it to win customers over.
Other reasons cited for the failure of similar products included cost, limited battery life, our attachment to mobile phones and unwearable design. Alongside smartphones, virtual reality headsets, smart watches and so on, smart glasses may be one gadget too many, especially as Apple entry level prices are still high for many consumers. Consumers have also been bruised by under-performing and even dangerous batteries, and smart glasses would be another device that drains the iPhone and needs its own charging.
In terms of design, many users ditched Google Glass because it was a long way from being seen as cool. Apple's product will need to be something we actually want to wear when we are on pubic view. The company may do well to root a new spectacle product in the functional minimalism of its smartphone and tablet ranges. Yet while that design ethos has lifted Apple to the number one spot in the last decade, those designs are now also being seen as becoming too safe and repetitive.
Microsoft is taking another tack with its HoloLens. In contrast to Google Glass, the device opts for an overtly tech look, an unashamedly prosthetic, even cyborg device. As a result, early reviews of the Hololens look past fashion design towards its potential for radical disruption.
There may be another more fundamental difficulty for Apple, however. Some commentators are suggesting current augmented reality technology is still too difficult for us to physically interact with. Apple would have to convince users that their new glasses are easy to use and will not lead us into brick walls or awkward interactions with family, colleagues, friends and strangers.
All this is important because Apple has been trading on long-past acts of creativity for years now. Judged by the mixed reaction to the Apple Watch, it's not yet clear that wearables can change this situation or that a new set of smart glasses will represent a genuine disruption. There's a chance that attempting to succeed with augmented reality will be seen as another "me-too" behaviour for the company.
Yet if Hololens or other products help augmented reality's day to arrive sooner, and if Apple gets things right in terms of design, user experience, confidence and trust, it could be a breakthrough for the company.