Backstory

I have quite an old LCD monitor and wanted to buy a new one for quite some time.
But I was planning to travel and wouldn't be able to bring the monitor with me.
Then a friend of mine shared an article with an intriguing title:
I ditched my laptop for a pocketable mini PC and a pair of AR glasses.

I had never heard of AR glasses before. Turns out they're basically a "dumb" monitor with a USB‑C connection, but the image is projected into your eyes, so it looks like it's floating. No additional software is required, and I can take it anywhere with me. So I decided to order one. The same friend later asked me for a review, but I decided to post it here and just share the link - maybe someone else will also find it useful.

Impressions

I went for the Xreal One. They are quite pricy, but I wanted to try something cutting-edge. There's also a Pro version, but according to this review on Reddit and this review on YouTube, it has several drawbacks - mainly reduced sharpness, which is important for coding.

The glasses aren't as comfortable as regular sunglasses — they're a little bit heavier, but I got used to them. They also generate quite a bit of heat on the top part of the frame. It can cause slight discomfort when it touches face, but I've gotten used to wearing them properly to avoid that. I can wear them for quite a long time, but I wouldn't use them for 100% of my screen time.

They have three levels of electrochromatic dimming (the lenses physically get darker). On the lowest setting (disabled), it's not fully transparent —
more like a sunglasses with a slight dimming. At the maximum level, it's extremely dark; even in a well‑lit room I can't see what's on the edges.
With dimming disabled, it looks the coolest — like an actual floating screen with a bit of transparency.
But the darkening is useful for a more immersive experience since it removes that transparency.
They also have "Auto transparency" option that automatically disables dimming when you turn your head away from the screen.
Also, the brighter the room is, the more noticeable the reflection on the bottom of the glasses due to the lens's prism design.
It's not an issue with the Pro version, but I didn't find it distracting at all, even in a well-lit room.

The screen is great. From video reviews, I was a bit worried that the colors would look like from a projector, but it's just impossible to capture this properly on camera.
In reality, the colors are nice. They also allow you to configure the color temperature, and I found the coldest setting the most comfortable.
The picture isn't very sharp — there's a bit of motion blur when I move my head around, and thin red or pink text on a black background looks slightly off.
I think it's a limitation of the technology, plus the screen is only 1080p. But it's not as bad as it sounds — I can still use it comfortably for coding.

By default, the screen is 16:9 with 120Hz, but you can switch to 32:9 or 21:9 with 60Hz.
I use 16:9 for gaming and 32:9 for productivity — 32:9 is so large, it's like two monitors glued together. I usually keep my browser on one side and something else on the other.
I also love playing retro games, and I can say that 4:3 content looks great. Since the screen is OLED, the black pixels don't emit any light, so the letterboxes fully transparent.

However, it's not the same as having an actual ultra‑wide monitor. The screen doesn't fill the entire surface of the glasses — that's what the FOV is about.
On my model, it's 50 degrees, which is quite large. But in ultra‑wide mode, I still have to rotate my head to see the other half of the screen.
So there's no peripheral vision like there would be on an actual ultra‑wide monitor.
Also, other people can't see what you're seeing, even if they're close — which can be both a good and a bad thing.

You can also configure how far the screen appears — anywhere from 1m to 10m — and its size in inches.
There are five size levels, and the values depend on the selected distance and whether ultra‑wide mode is enabled.
I usually use 1m for productivity and 4m for gaming and multimedia. My preferred size is the "middle" (third) level,
which is designed to fit the entire screen without me needing to rotate my head (except when ultra‑wide mode is enabled).
For 1m these sizes are 35″ for 16:9 and 64″ for 32:9; at 4m they're 140″ and 255″ respectively. The large screen feels very immersive — it's like being in a cinema.

The glasses also have three view modes:

• Anchor. I can rotate my head freely and The screen stays fixed in space. However, if I walk around, the screen moves with me (which is what 3 DoF means). This is the mode I use most of the time.
• Follow. The screen rotates along with your head. I don't use this mode much.
• Side view. Similar to Follow, but the screen is positioned in the corner. I use it when I'm doing chores and want to watch something.
  They also have a stabilizer enabled by default, which smooths the screen movement when you move your head.

To use the glasses, you need a USB‑C video output. My motherboard supports it, but to enable it I had to connect my video card to the motherboard via DisplayPort.
I never heard about a connection like this before, but it's from my motherboard manual. It does make sense, though — the GPU provides the video output,
and the motherboard wouldn't know about it otherwise. Software‑wise, it works out of the box with my KDE Plasma setup on Arch Linux.
The only issue I'm noticing is some small visual glitches for the first few seconds after connecting. On PC I use it together with my regular monitor.
The mentioned "Auto transparency" pairs nicely with it. However, it's not perfect, since I'm still looking at the second screen through what's basically
a pair of light sunglasses. So I usually don't put anything important on it.

As for phones, neither mine nor my wife's supports video output. But from reviews, I think it wouldn't be very convenient to use with a phone anyway.
First, the phone's screen has to stay on, otherwise the glasses won't display anything. Second, you can't interact with the phone through the glasses, so you have to look at the phone itself.

But I found a great option to use the glasses with. I have a Retroid Pocket Flip 2 — a pocketable retro console that runs Android and supports video output.
Unlike a regular phone, it automatically turns off its built‑in display when a second screen is connected. It also has physical controls, so I don't need to use a touchscreen.
The Android UI isn't perfect for a gamepad, but it works. Streaming to it also works great because, even though the screen is disabled, the touch input still works — so it basically becomes a touchpad. Since the device is a clamshell, I sometimes use an 8BitDo Micro as an input device to avoid opening it, which is especially convenient for quickly pausing videos. This gamepad can also act as a keyboard via a special switch on it, so it works nicely when I stream from my PC too.

I also have a Steam Deck, but there's not much to add — it just works without any issue.

The glasses also have built-in speakers. I like their design: you don't put anything inside your ears — the speakers are integrated into the frame near where your ears are, so they kind of "whisper" to you. Others can hear them only at high volume. This affects the sound quality, so music doesn't sound as good as on quality headphones, but I think it's a worthy compromise. And it's still possible to wear regular headphones with the glasses.

They also have a shortcut button on the frame. I assigned screen off on regular press and ultra-wide mode on hold.

The firmware is proprietary, but it doesn't use the internet. And what I liked is that updates are installed through a web browser.
However, it has to be a Chromium‑based browser on Windows or Mac.
Luckily, I have a dual‑boot, so I rebooted to update the firmware.
The update added support for 16:9, so it looks like it's not just for bug fixes.

The glasses can be equipped with prescription lenses, but I wear contact lenses and those work as well.

They also have a camera add‑on called Xreal Eye. It's a small camera that unlocks 6 DoF tracking and can also take photos and record videos. The media is stored directly on the glasses, which have 2GB of space, and can later be transferred to a phone or PC over a cable. I haven't bought it yet, but I'm considering it since I'm interested in having 6 DoF.

Conclusion

I love these glasses, it's easily my favorite portable option. It's a huge screen I can take anywhere with me and put where I want. I don't mind that it's only 1080p, none of my portable devices can fully handle 4k anyway.

Since they are better then my current monitor, I use them with my PC too. But I don't think it's a proper replacement.
If you don't need portability, regular screen will be better and cheaper.