Understanding XR: The Evolution of Reality Itself
- Tal Wainer-Katsir (Tal m3Dical)
- Jan 26
- 4 min read
There's a phrase I often hear:
“VR, XR , it's all the same thing, right?”
That’s a bit like saying “cheese and cottage cheese, same thing.” They sound similar, but they’re not.
The truth is that VR is only one part of a much broader umbrella called XR, Extended Reality.XR includes all the “realities” we know: VR, AR, MR, but also two earlier eras, CR (Classic Reality), the age of stationary computers, and PR (Portable Reality), the age of mobile devices.
We all already live in those first two stages.This article focuses on the next three, VR, AR, and MR, or in one word: XR.
Behind those letters lies a story about the evolution of reality itself, about how we experience, learn, and shape the world around us.
One Reality, Five Stages
So how did XR emerge, and what does it have to do with our perception of the world?
Over the past few decades, we've gone through a series of technological revolutions that didn’t just change our tools - they reshaped our understanding of reality itself:
Classic Reality (CR) - our physical, screen free world.
Portable Reality (PR) - the mobile era, when the phone became a window to another world.
Virtual Reality (VR) - a fully computer generated environment.
Augmented Reality (AR) - a digital layer projected onto the real world.
Mixed Reality (MR) - an interactive blend, where virtual objects respond to real world surfaces and lighting.
Finally comes eXtended Reality (XR) - the umbrella that connects all these worlds together.
VR - When We Step Into Reality
Virtual Reality allows us to experience an environment that exists entirely in the computer whether real or imagined.Through vision, motion, and even touch (via controllers, gloves, or haptic devices), we become part of a virtual world.
In medicine, VR is far from a gimmick:
It enables interactive 3D learning of anatomy.
It trains surgeons and prepares patients for procedures.
It helps in trauma recovery and rehabilitation.
It transforms dry CT scans into living, explorable models.
This is where we learn to disconnect the body from the physical world, to shift from observer to participant. In VR, we don’t just see the world, we exist inside it. It’s the first time our consciousness learns to experience space while the body stays still.
Yet with all its power, VR also has limitations: limited bandwidth, motion sickness, heavy headsets, and sometimes social isolation. In a world already filled with screens, even virtual reality needs boundaries.
AR & MR — Digital Layers Over the Real World
Augmented Reality isn’t new - it’s simply evolved.Think about the weather graphics on TV, or the yellow offside line in a soccer match - that’s already AR. Today it's everywhere: in Google Translate's live sign translation, in navigation apps, jewelry fitting tools, or IKEA's furniture placement app.
In medicine, AR and MR allow us to:
Project anatomy directly onto the patient’s body.
Navigate through organs in real time.
Receive remote expert guidance from anywhere in the world.
Perform precise surgical simulations using systems like Surgical Theater, Medivis, or Novarad VisAR.
The Thin Line Between AR and MR
The difference between Augmented Reality and Mixed Reality is subtle - but meaningful.
In AR, the digital layer “floats” above the real world. It’s projected onto reality but doesn’t interact with it.
In MR, the digital layer responds to the physical environment — recognizing surfaces, reflecting light, casting shadows, and becoming part of the scene.
In AR, a digital ball passes through a table. In MR, it stops on top of it.
Registration - Aligning the Virtual and the Real
Here comes the crucial concept of Registration - the precise alignment between the digital model and the physical body.
There are six main methods:
Markers – using at least 3 uniquely identifiable codes detected by the system.
Landmarks – at least 3 real-world points recognized in both the digital and physical space.
Contour Recognition (2D/3D) - matching outlines captured by the camera to the 3D model.
Automatic Scanning - surface mapping that aligns the digital model with the real object.
Without accurate registration, even the most advanced technology won’t be precise enough for medical use. And it's not plug & play - every millimeter of deviation in the virtual world can become critical in the real one.
XR - The Grand Synthesis
For me, XR isn't just technology - it's a new way to see the human body. It lets me move between worlds seamlessly: to plan a surgery in VR,analyze data through AR, interact with instruments in MR, and then evaluate outcomes in the physical world.
With a single click, I can move from a 3D screen to standing beside the operating table, where the data overlays reality itself. It's hard to describe in words, because it changes how we think about “reality” altogether.
What’s Next?
Here come the Metaverse and the Internet of Things (IoT). When every device, from printers to ventilators — is connected, and live data updates in real time within virtual environments, we approach a world where every layer of reality communicates with the others.
In medicine, the implications are profound:when the ventilator, catheter, and AR display all “speak the same language,” it’s no longer science fiction — it’s a smart, real-time ecosystem that enables faster, safer, and more human decisions.
But let’s remember:
“In tech we trust — until we don't.”
Technology is incredible, but it's only a tool. To use it wisely, we must understand both the human body and its limits.
When the digital, physical, and human layers truly merge, XR becomes more than innovation, it becomes a new language of connection between worlds, where reality and imagination are no longer two separate sides of the same screen.
In Summary
XR isn't the future, it's the evolving present. It’s already transforming how we learn, train, operate, and design the future of healthcare. But more than anything, it's changing how we understand ourselves.
This article was inspired by a lecture I delivered at HIT, Holon Institute of Technology, and by countless hours of collaboration with experts at the Levin Center for Surgical Innovation at Ichilov Medical Center, Tel Aviv.And by hundreds of moments where imagination met reality, in surgery prep, in the lab, and through the lenses of a HoloLens headset.
Comments