Passthrough (mixed reality)
Also known as: passthrough, video passthrough, colour passthrough
Passthrough is a feature of virtual and mixed reality headsets that uses outward-facing cameras to show you a live video of the real world inside the headset.
Digital content can then be layered on top, so a virtual screen can hang on your actual wall. While modern colour passthrough is impressive, it's still a camera feed, not your own eyes, so it can show blur, distortion, and slight delay.
Passthrough (mixed reality), explained at three levels
At home
Imagine wearing a blindfold with tiny video cameras glued to the front, feeding a live picture to screens in front of your eyes. That's how passthrough works in a VR headset. The cameras film the room, and the headset shows that video almost instantly, so you can see your coffee table or your dog. Apps can then add virtual objects into that live view.
At work
Passthrough is a headset feature that uses outward-facing cameras to show the wearer a live view of their surroundings. It lets people use headsets safely in real spaces and makes mixed reality possible, where digital content such as instructions or 3D models appears on top of real equipment. For businesses, it turns VR headsets into tools for training, maintenance, and design review.
At home
There are two ways to mix real and virtual. Video passthrough, used by Quest 3 and Vision Pro, films the room and shows it on screens with graphics drawn in. Optical see-through, used by HoloLens and AR glasses, lets you look through clear lenses while a projector adds light. Video passthrough can show solid, dark virtual objects, while optical see-through gives a natural view but makes graphics look ghostly.
At work
Video passthrough is a processing pipeline. Cameras capture the scene, then the headset corrects lens distortion, reprojects the image from the cameras' position to where your eyes actually are, matches colour and exposure, and composites virtual content. All of that must happen in roughly 10 to 20 milliseconds. Developers reach passthrough through platform APIs and OpenXR extensions, and platforms often restrict raw camera access to protect bystanders' privacy.
At home
Your brain expects what you see to match what your body feels. In passthrough, there's always a short gap between moving your head and the cameras' updated view reaching your eyes. Headsets hide it by predicting your head motion and warping the image, but any leftover delay makes the room seem to swim. In my view, low latency matters more than resolution for passthrough comfort.
At work
Enterprise deployments run into specific limits. Camera access policies often block raw feeds, so apps for inspection or computer vision need special enterprise permissions. Cameras struggle in dim warehouses and next to bright windows, and their limited dynamic range makes screens and gauges hard to read. Safety certification matters near machinery. Scene understanding, which detects walls, furniture, and hands, builds on passthrough to anchor content, so test it in the real site.
Real-world examples
At home
Thomas uses his headset's passthrough mode while exercising, so he can see his furniture around him while a virtual coach appears in the middle of his living room.
At work
Carlos is a training manager at an Ontario manufacturing plant. Trainees use headsets in passthrough mode at real machines, with digital arrows and safety warnings layered over the equipment.
How it compares
| feature | Video passthrough | Optical see-through |
|---|---|---|
| How you see the world | Camera feed on screens | Directly through clear lenses |
| Digital content quality | Solid, opaque visuals | Often translucent |
| Real-world clarity | Limited by cameras | Natural |
| Examples | Quest 3, Vision Pro | HoloLens, AR glasses |
Video passthrough controls everything you see. Optical see-through keeps your natural view.
For analysts
If you're piloting mixed reality at work, test passthrough quality in your real lighting conditions. I'd do that before buying devices, since dim warehouses or bright windows can make camera feeds hard to use.
History & origin
Early VR headsets offered grainy black-and-white passthrough mainly for safety, so users could see their surroundings without taking the headset off. Microsoft's HoloLens, in 2016, took a different route, 'optical see-through,' projecting images onto transparent lenses. Meta's Quest Pro introduced colour passthrough in 2022, and the Quest 3 in 2023 made higher-quality colour passthrough affordable. Apple's Vision Pro, in 2024, relied entirely on video passthrough with very low delay, and Samsung's Galaxy XR followed in 2025. In my opinion, good passthrough is what turned VR headsets into mixed reality devices, because it removed the feeling of being cut off from the room.