Between portable cinema and AR promises: What display glasses can really do
Display glasses are often misleadingly marketed as "AR glasses." In this article, we clarify what the technology can really do and where its limits lie.
Manufacturers such as Xreal and Viture are flooding the market with so-called "AR glasses" –, a description that does not really fit the devices.
(Image: Xreal / heise medien)
Anyone currently scrolling through YouTube's technology channels or visiting electronics trade fairs will increasingly encounter so-called "AR glasses" from manufacturers such as Xreal, Viture, and RayNeo. In many cases, however, these are not devices with genuine augmented reality functionality, but rather display glasses. These focus on image quality rather than environment recognition, offer large virtual screens, but do not master any core AR technologies. To prevent the manufacturers' marketing machinery from causing even more confusion, this article explains how display glasses work and how they differ from smart glasses and AR glasses.
How do display glasses work?
Display glasses, also known as video glasses or wearable displays, are essentially head-mounted displays (HMDs) that project a digital image directly into the field of vision. Instead of a physical screen, they use micro-OLED or micro-LED panels to create a stereoscopic image that looks like a 100- to 175-inch screen standing a few meters away. Technically, many models offer full HD resolution for each eye, a field of view (FoV) of 45 to 57 degrees, and refresh rates between 60 and 120 hertz.
So-called birdbath optics are used for image guidance, which work as follows: The displays are mounted in the frame above the lenses and point downwards. A semi-transparent mirror directs the light from the displays into the eye via several reflections. Through the lenses, you can still see the real environment, in which a very bright but minimally transparent virtual screen now appears to float.
Birdbath Optics in Display-Drillen (2 Bilder)
RayNeo Air 2 Birdbath
Josef Erl
)To ensure that this remains clearly visible, the lenses greatly darken the ambient brightness. The advantage is that the virtual screen is relatively bright. However, the disadvantages are visible reflections in the image, as it cannot be completely isolated from the outside world, a narrow field of view, and a less transparent optical system – similar to wearing strong sunglasses in a poorly lit room. New devices such as the Xreal One Pro feature electrochromatic dimming in the lenses, which regulates the amount of light entering the glasses at the touch of a button or automatically. Earlier generations had clip-on attachments to darken the lenses completely. The glasses therefore only display a video feed from the connected device, which is also used to operate them. The operating system and the manufacturer's own apps are also accessed via external devices. Buttons on the frame can only be used to adjust device settings such as brightness, volume, or frame rate.
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Market overview: Xreal, Viture & Co.
Among the best-known manufacturers is Xreal (formerly Nreal), whose models are designed for media consumption and gaming. The latest devices, Xreal One and One Pro, use Sony MicroOLED panels with 1920 Ă— 1080 pixels per eye. The Pro version features a customized birdbath optics called "flat prism optics," which is slightly more compact and allows for a larger field of view. With the optional "Xreal Eye" camera, the glasses recognize spatial depth to anchor the virtual screen in the room.
Viture Luma-Serie (4 Bilder)
Viture Luma Smart Glasses
Viture
)With the Viture One, Viture initially positioned itself as a gaming-focused alternative. –, including compatibility with cloud services such as GeForce Now and PlayStation Remote Play. However, the new "Luma" product range includes four models aimed at different target groups. The Ultra version also enables simple spatial interactions within closed software. Other manufacturers such as TCL, Rokid, Lenovo (Glasses T1) and RayNeo offer similar specifications but differ in terms of design, weight and software integration.
Limitations: No real AR functions
Most display glasses currently lack independent sensors for analyzing the environment. Tracking is only possible with optional accessories. These devices, which are usually puck- or smartphone-shaped, are inserted between the playback device and the glasses. The built-in computing power enables software-based 3DoF tracking, which allows the head to be rotated without the virtual image permanently following it.
The latest generation of devices calculate this freedom of movement even without additional devices using a chip in the housing and obtain additional information via a built-in camera (e.g., Vulture Luma Pro) or an optional clip-on camera (e.g., Xreal Eye). This increases the freedom of movement to 6DoF. In practice, this means that the displayed window can be anchored firmly in the room. Head movements, whether sideways, up and down, or forward and backward, do not change the position of the image. In the future, rudimentary hand tracking may also be possible with these devices.
(Image:Â Xreal)
Despite the term "AR glasses" being popular with manufacturers for marketing reasons, display glasses lack the central technology for true augmented reality, such as SLAM (Simultaneous Localization and Mapping), spatial sensor technology, or spatial anchors. Without these components, digital content cannot be anchored stably in the real environment.
It is also not possible to recognize surfaces or objects. The projected image always remains in front of the field of vision ( – with the exceptions mentioned above – ), regardless of head movement. This prevents interaction with real objects or the precise placement of digital content on tables, walls, or floors.
Clear distinction from smart glasses
Even current smart glasses such as Meta's Ray-Bans or the Even Realities Even G1 should not be confused with display glasses and pursue a different goal: They focus on everyday usability, voice control, microphones, speakers, and cameras for photos and videos. Even if they have display screens, like the Even G1, these are limited to simple information such as lines of text or symbols.
(Image:Â Ray-Ban | Metat)
Display glasses, on the other hand, generally do not offer any assistance functions and focus exclusively on the visual experience, which is provided in high quality and with a larger field of view. While smart glasses function as digital companions in everyday life, display glasses are portable monitors for media consumption. A combination of the two is not currently possible, as the technology required for display glasses prevents a similarly slim design to the Meta Ray-Ban Smart Glasses and always requires a wired playback device.
Who benefits from display glasses?
Despite the lack of AR and AI features, display glasses naturally have their place. They offer particular advantages when traveling: on planes or trains, for example, users can enjoy movies or series on a virtual big screen without having to rely on mobile displays. Those who work with sensitive data can stream their laptop screen directly to their glasses without anyone else being able to see it.
(Image:Â Xreal)
Display glasses are also interesting for mobile gaming with the Nintendo Switch, Steam Deck, or ROG Ally. One exception is the Nintendo Switch 2, which shields its USB-C signal from third-party accessories. Here, display glasses can only be connected using adapter solutions or intermediate devices.
However, anyone looking to purchase display glasses as a space-saving alternative to a large TV should be warned: they are only suitable for extended gaming sessions or binge-watching the latest Netflix series to a limited extent. For one thing, the glasses only run for as long as the battery of the connected smartphone or handheld device allows. They do not have their own power supply. For use with Xbox, PlayStation, and other consoles, expensive additional devices must be purchased to supply power to the glasses in addition to the image signal. On the other hand, the permanent display of the bright image can quickly tire the eyes, which can impair viewing pleasure in the long run.
Conclusion: Media glasses with clear limitations
Display glasses are specialized devices for media use. They are technically mature, but conceptually limited. They offer a new level of mobility for movies, games, or working on a laptop, but have little to do with true augmented reality. Those hoping for digital objects in the physical world will either have to wait for devices such as Snap Specs or Meta Orion, or for the more expensive AR glasses such as Magic Leap One or HoloLens . However, display glasses remain a practical, clearly defined device class that has found its niche between bulky mixed reality headsets and compact smart glasses.
(joe)
