🕶️ How XR Headsets Work: What Happens When You Put On a Virtual Headset

Adrian Bartoň
Oct 27
3 min read

Virtual reality feels like magic at first glance. You put on the headset, find yourself in a completely different world, everything reacts to your movements, and sound surrounds you from every direction. But what’s really happening inside the headset when you dive into the XR world?

Let’s take a look beneath the surface — quite literally.

Displays and Optics: Windows into Another World

At the core of every XR headset are the displays — usually two, one for each eye. The most common types are OLED or LCD panels, and the newest devices already use microLED technology. These displays render a stereoscopic image, meaning each eye sees a slightly different perspective. The brain then merges both images into a single picture with depth — a space you can look around in.

Between your eyes and the displays are lenses that bend the image so it appears natural and sharp. The main factors that define image quality are:

Resolution – the higher it is, the sharper the image.
FOV (Field of View) – determines how wide your vision is.
Refresh rate – how many times per second the image is refreshed (at least 90 Hz for a smooth experience).

Motion Tracking: How the Headset Knows Where You’re Looking

XR headsets must know exactly where you are and where you’re looking. This is made possible through different types of tracking:

Inside-out tracking – cameras built into the headset track your surroundings and calculate your position (e.g., Meta Quest).
Outside-in tracking – uses external sensors or base stations that track the headset from the outside (e.g., HTC Vive).

Thanks to these methods, the headset recognizes 6 degrees of freedom (6DoF) — movement forward/backward, sideways, up/down, and rotation along all axes.Increasingly, eye tracking (tracking eye movement) and hand tracking (recognizing hands without controllers) are also used.

The Processing Brain: Chips and Rendering

Inside the headset lies a powerful processor — often a specialized XR chip (such as the Qualcomm Snapdragon XR2).It processes visuals, monitors sensors, recalculates position, and ensures everything runs smoothly. To keep your brain and body in sync, latency (the delay between movement and display) must be below 20 milliseconds.

To maintain smooth performance, technologies like these are used:

Reprojection / Timewarp – predict head movement to prevent image stutter.
Foveated rendering – renders full detail only where you’re looking, saving performance.

Sound and Space: Hearing the World Around You

Sound is often underrated, yet it plays a crucial role.Modern headsets use spatial audio — sound that changes based on the direction you’re facing.When you turn away from a source, it becomes quieter.This helps the brain believe that you’re truly in a 3D space, not just watching a screen.

When Everything Works Together

Think of it as an orchestra:

Displays create the illusion of the world.
Sensors track every movement you make.
The processor connects reality with virtual space.
Sound adds depth and presence.

The result? A sense of presence — that moment when your brain forgets that what it sees isn’t real.

🎯 Summary

An XR headset is a brilliant combination of optics, sensors, processors, and software.Together, they build a bridge between the physical and digital worlds.That’s why, when you put on a VR headset, you don’t just see an image — you experience an entirely new world.