In 2024, augmented reality headsets are now affordable enough that some average consumers received a pair last Christmas, yet they are unlikely to form the top fashion craze for the year. In 2013, Google Glass was the first commercial AR device to enter the public consciousness. While the product line had a successful ten-year lifespan for enterprise users, poor social acceptability quickly killed off consumer-focused versions. Privacy concerns due to the onboard camera spawned the term “glasshole” for users, with the device’s appearance doing little to help this.
AR headsets use components known as optical combiners to overlay digital content from displays on top of reality. Today, cousins of AR glasses with no displays, like Meta and Ray-Ban’s latest smart-glasses, are increasingly hard to distinguish from normal spectacles. Between these headsets’ recording indicator lights next to their cameras and the ubiquity of smartphone cameras arguably increasing public tolerance to being filmed, concern about these wearables’ privacy or social acceptability seems much more muted in 2024 than a decade ago. If privacy is now a limited concern here, why are today’s lower-cost AR devices only just making the case for social acceptability?
Optics form the design center of AR headsets
As detailed in IDTechEx’s market research report, “Optics for Virtual, Augmented and Mixed Reality 2024-2034: Technologies, Players and Markets“, optical combiners do not just define the visual experience of an AR headset wearer. These specialized optical components overlay images from displays on top of reality: waveguides are a well-known type. Low-efficiency combiners (nits/lumen) require brighter displays, leading to larger batteries, challenges in thermal management, and bulkier devices. Compared to other combiner types, like the birdbath combiners used in many low-cost AR headsets, waveguides are generally less efficient, but otherwise, they seem like the technology of choice to lead toward socially acceptable AR glasses.
The outward aesthetics of AR optics have an outsize impact on a headset’s overall appearance, which is key to making headsets attractive to wear in public. While birdbath combiners are relatively bulky, diffractive waveguides from companies like Meta Bounds and Vuzix are becoming hard to distinguish from normal spectacle lenses, with reflective waveguides (which are more efficient) not far behind here. While some other combiner types, particularly freespace holographic combiners as used in Google’s possibly canceled Project Iris prototype headset, come close to waveguides in this respect, they cannot simultaneously compete in terms of field of view and/or eyebox. This reduces possible use-cases and requiring headsets to be customized to individual wearers, although the higher efficiency still makes them a significant contender for use.
For an AR headset to be truly socially accepted, it must be possible to converse with the wearer while holding full eye contact. This problem is difficult to solve with birdbath optics, with mirror coatings obscuring the eye from outside observers. Diffractive waveguides formerly struggled here as well, with “eyeglow” (leakage of light from the outer face of the optic) making the eyes difficult to see, as well as presenting potential privacy concerns. In 2024, this is no longer the case, with innovations in grating design leading to waveguides from Dispelix and others having near-zero detectable eyeglow. This removes a key adoption barrier for waveguides in consumer devices.
Problems solved and not yet solved in the contribution of optics to socially acceptable AR glasses. Source: IDTechEx
Devices like the Apple Vision Pro are paving the way for AR glasses
Mixed reality-capable headsets like the Vision Pro and Meta’s Quest 3 will go a long way to establishing the utility of AR headsets and expanding libraries of content, but even advanced features like Apple’s outward-facing display are not likely to make these devices commonly worn in the street or on public transit. The “fail-deadly” nature of devices optically closed off from the real world is unhelpful, too. In contrast, AR headsets are already approaching aesthetic parity with everyday eyewear and could allow computing to blend more seamlessly into life.
The elephants in the room here are cost and immersion. Waveguide optics remain relatively expensive and typically form the most expensive single components on the bill of materials of AR devices using them. The few consumer AR devices released that use the technology tend to be costly as a result while having a limited FoV. Innovations like the adoption of resin substrate materials help with manufacturing costs but negatively affect immersion by reducing the maximum possible FoV. While continued R&D will help reduce costs, economies of scale will be just as important. By proving the worth of AR headsets for consumers, today’s MR-capable VR devices are an important tool in the arsenal of tech companies looking to push AR headsets towards mass adoption, activating the production cost savings that come