Meta's (META  ) Reality Labs hosted a recent virtual roundtable, using four prototypes to illustrate the company's path toward creating a VR experience that passes the "visual Turing Test," where the real and virtual are indistinguishable. Dubbed "time machines" by Meta, each prototype acts to address some aspect of the VR experience where current technology is falling short, namely: resolution, focal depth, eye tracking, and dynamic range.

None of the models are store ready or will be, but rather work as proof of concept, with many incorporating bulky tech to achieve a specific technical feat.

The prototype dubbed Starburst, for instance, has a lamp so bulky that it must be held to the face like a pair of binoculars, with Meta CEO Mark Zuckerberg himself admitting that the design is "wildly impractical."

Nevertheless, Starburst achieves 20,000 nits of brightness, a more than exponential leap from the Meta's more familiar Quest 2, which can only manage 100. Starburst represents Meta's effort to improve dynamic range or HDR to lend more realism to colors.

The prototype Butterscotch focuses on improving image resolution, but, as with Starburst, this meant compromises. Butterscotch may have two and half times the resolution of the Quest 2, but it has half the field of view. Nevertheless, Butterscotch's resolution is high enough to read an eye chart in 20/20 vision.

The headset Holocake 2 is Meta's thinnest ever, thanks to the incorporation of holographic optics to bend light, which lends flat surfaces a sense of depth and dramatically reduces the device's profile. One of the main challenges concerning holographic optics is finding a light source, likely a laser, that is consumer-ready. Still, once Meta hones the tech, VR headsets as thin as a pair of sunglasses are possible.

"The goal of all this work is to help us identify which technical paths are going to allow us to make meaningful enough improvements that we can start approaching visual realism," said Meta CEO Mark Zuckerberg.

One of the other featured designs, Mirror Lake, hasn't even been built. Mirror Lake incorporates the thin profile of Holocake, the improved range of Starburst, and the retina-grade resolution of Butterscotch, showing "what a complete next-gen display could look like," said Reality Labs chief scientist Michael Abrash.

It stands to reason then that Mirror Lake, or something like it, will likely act as Meta's flagship headset as it works to bring its namesake metaverse into reality, and in Meta's metaverse, people don't take off their VR headsets. Mirror Lake, for instance, outwardly projects the user's eyes to convey a sense of presence.

Nevertheless, Meta's Reality Labs recently posted a $2.9 billion, and the company has seemingly scaled back some of its efforts by delaying the release of its first lineup of AR glasses.

Looking ahead, Meta plans to release its first-ever headset to feature eye-tracking, Project Cambria, later this year as part of its upcoming lineup of high-end headsets. When some of the other tech featured at the round table will hit store shelves is anyone's guess.

In the meantime, Mark Zuckerberg remains optimistic.

"I think we're in the middle right now of a big step forward towards realism," he said. "I don't think it's going to be that long until we can create scenes with basically perfect fidelity."