If blackout curtains aren’t enough, tuck yourself into zDen’s pop-up blackout tent

A few months ago, I was out for my friend Blaise’s going-away drinks, and towards the end of the evening, the conversation shifted to a roundtable of sleeping habits. I tried to stay out of it; what was I going to do, bring up the tent again? Before I had time to decide, Blaise enthusiastically chimed in: “Tracy sleeps in a blackout tent!”

When it comes to getting a good night’s sleep, a sensitivity to light is my Achilles’ heel. The sun could peer through the edge of a blackout curtain, work its way up under my eye mask, and instantly, I would be awake, feeling as though it weren’t just my eyes, but also my skin sensing the light in a room. In my hunt for a cocoon of darkness I came across the zDen and was intrigued by the claim that it can block out 99% of light.

The zDen became part of my nightly routine in May 2025, after a short-lived attempt at taping up silver-backed blackout photography panels to my bedroom windows, which, as a neighbor pointed out, was giving my house a very distinct “a-conspiracy-theorist-lives-here” look.

Essentially, zDen is a pop-up sleeping tent made from non-toxic fabric, large enough to fit a queen-sized pillow and cover me down to the lower part of my ribcage. From my own testing, two people can squeeze in back-to-back, albeit with little room to move. The two front flaps can be pulled to the side like curtains or kept closed with Velcro. Its three mesh windows with flap covers can let air in, and it even has pass-through openings for CPAP users.

Of course, I have to address the big question: yes, it is a bit silly-looking. I’ve seen the reactions when I bring it up in conversation. A look washes over someone’s face that says: “This is odd. Have you realized that this is odd?”

There’s no way around this, other than to strive to become unembarrassed. I don’t think of the zDen as an indoor tent so much as a light-pollution blocker, one that looks no more or less ridiculous than a red light mask, a portable sauna, a cooling neck fan or all the other gadgets that humans have dreamed up in order to feel and be well.

I’ve used the zDen nearly every night since I bought it. Its absence is a guarantee I’ll wake up every two hours with my neck at an ungodly angle, face smushed into a pillow and a blanket pulled over my head. Before, I had assumed I was a natural stomach and side sleeper, having never considered that my habits could be the result of unconscious attempts to shield my eyes from light. Perhaps the most unexpected benefit of sleeping in the zDen has been an easy transition into sleeping on my back and staying asleep throughout the night.

It has also been a lifesaver for traveling, where I never know how dark my accommodations will be. This past June, the zDen folded down into its included carrying case and joined me on a three-week road trip around Ireland, where daylight lasted up to 17 hours. It helped me stay asleep everywhere from a curtain-less B&B on a rocky island off the west coast to a treeless campground in the Wicklow Mountains (though the tent-within-a-tent setup was a little avant-garde).

There is one caveat: the zDen folds down into an 18in circle, but that was 3in too wide to fit in my carry-on luggage. According to Danielle Fujii, zDen’s creator, it can technically be folded further to fit, but that adds tension on its frame. Not wanting to risk any damage, I opted for the standard folding configuration and checked the bag, officially making the zDen the only thing I’ve ever justified checking a bag for.

Fujii created the first prototype out of blackout curtains to assist with migraine relief. “I could not find anything on the market that provided the darkness I needed without putting something directly on my face,” Fujii said. I relate as someone who has suffered from migraines for decades. But Fujii has seen it become a valuable tool for many people, including shift workers, travelers and those who share sleeping quarters. And even animals: zDen offers a smaller version for pets, though my cat Tux prefers to take his afternoon nap in the human-size version.

Every so often, as it happened the night Blaise brought up the topic, I find myself in conversation with a couple who are at opposite ends of the light sensitivity spectrum. Inevitably, I’ll be pulled aside by the more sensitive of the two, who asks: “Hey, can you send me a link to that tent thing?” And I go to sleep that night, in my silly little blackout tent, knowing I have brought another person over to the dark side.