VR is managing to achieve lower costs and higher resolutions; however, one thing hasn’t changed: They are no synonym for comfort and form factor.
Nearly four years after Facebook launched its Oculus Rift, most of the market is still following a VR goggle-style design that is bulky and covers almost the entire top of the head. These headsets contain a display rectangle and are held in place using straps or over-the-skull supports.
Heavy VR headsets can increase the burden on the cervical spine and risk neck strain. They are also challenging cumbersome devices when used in a shared space, with cords making them a bit of a safety hazard.
Nevertheless, a new generation of lightweight devices is generating renewed interest in the future of VR. These portable, sleek-looking glasses are made possible by the development of extremely compact and powerful display technologies.
Facebook’s new proof-of-concept VR headset looks like a pair of large sunglasses that can comfortably sit on your ears, separating them from most bulky VR devices available today.
Even though the new optical architecture is significantly more compact, the glasses can potentially offer better visual performance. The display has a thickness of less than 9mm, yet the field of view is, according to Facebook, comparable to today’s main VR products.
The glasses beam images to the user’s eyes using what FB called “holographic optics.” This means that the glasses developers have replaced the curved refractive lenses from most VR headsets with laser light. The holographic optic can bend light but looks like a thin, transparent layer.
Another technique the glasses use is polarization-based optical folding. With it, light can be moved both forward and backward within the lens, traversing the space multiple times. This allowed developers to reduce the amount of space needed between the display and the lens.
The design, which combines holographic film, laser projection, and directional backlights, can deliver flat images or volumetric holographs in a screen that is a mere 9mm to 11mm thick. The resolution would be roughly 1,200x1,600 pixels, comparable to traditional VR goggles, with an impressive 93-degree circle (or 92 by 69-degree rectangle) field of view.
Facebook’s glasses are still a concept, but it seems to be rooted in solid research and promising technological advances.
Other Lightweight Options
Facebook’s are not the only lightweight, comfortable, and high-performance VR glasses in development.
In January 2020, Panasonic revealed a set of eyeglasses with micro OLED panels and UHD resolution. The panels are the first to support HDR colors in VR and are expected to make the virtual world much more vivid. To achieve their optical module for natural and distortion-free images in single focus, Panasonic collaborated with 3M and Massachusetts-based Kopin Corporation. Their product is light, compact, and can be worn without a headband.
Nreal’s Light AR glasses debuted in 2019. The Beijing-based company partnered with Qualcomm and LG Uplus to connect their lightweight glasses to smartphones, where most of the computing is done. With investments from China Everbright Limited New Economy Fund, Shunwei, iQiyi, and China Growth Capital, among others, the company provides lightweight sets that take advantage of 5G to deliver immersive experiences everywhere. The glasses weigh 88 grams, have a 52-degree FoV, and a 1080p resolution. They are already available in South Korea for the equivalent of around $600.
The Future of Lightweight VR
When Facebook introduced its Oculus set seven years ago, the prototype had a screen resolution of 800x640 per eye and was held together with duct tape and straps. Today, Oculus Quest offers an all-in-one wireless gaming headset with a display that weighs only 571 grams.
Replacing deep lens systems with near-eye holographics means the volume of headsets can be cut by at least 75%. Facebook’s new VR glasses are expected to weigh less than 10 grams. Although the glasses are not ready for near-term development, the company has created three prototypes with LCD illumination systems and laser full-color.
Facebook is not the only business working on holographic optical systems. Apple recently acquired Akonia, and Samsung backed a waveguide display developed by DigiLens. In Germany, the Fraunhofer Institute is also working on smaller VR screens that can significantly reduce their volume.
The global VR market size is expected to grow at a CAGR of 21.6% from 2020 to 2027. Comfortable, easy to wear eyeglass-style VR options won’t make VR widely adopted on their own, but they can definitely provide a strong push forward.
About the Author
Yisela Alvarez Trentini is an Anthropologist + User Experience / Human-Computer Interaction Designer with an interest in emerging technologies, social robotics, and VR/AR.