We get asked this a lot in the shop: should you spend money on blackout curtains, or is a sleep mask from the drugstore just as good? The honest answer is that it depends on your room, your habits, and how sensitive you are to light while you sleep. Both tools solve the same problem in very different ways, and each one has trade-offs that only show up after you've used it for a week or two.

In this guide we'll walk through how each option actually blocks light, where they fall short, what they cost to buy and maintain, and which situations call for one, the other, or both at once. We'll also flag the mistakes we see most often, so you can skip the trial-and-error part.

Why darkness matters for falling and staying asleep

Your body reads light as a signal to stay alert. Even small amounts, like the glow from a streetlamp through a thin curtain or a phone charger LED, can suppress melatonin production and make it harder to fall asleep or stay asleep through the night. Research on light exposure and sleep has shown that even 40 lux of light, roughly what you'd get from a dim hallway bulb, can shift your body's internal clock if it hits you at the wrong time.

This matters more for some people than others. Shift workers sleeping during daylight hours, people who live in cities with bright signage or streetlights outside their windows, and anyone dealing with early summer sunrises will notice light interference the most. If you've ever woken up at 5 a.m. in June without an alarm, that's daylight doing exactly what it's designed to do: wake you up.

Both blackout curtains and sleep masks aim to remove that signal, but they work at different points in the process. Curtains stop light before it enters the room. Masks stop light right at your eyes, regardless of what's happening in the room around you. That distinction explains most of the differences we'll cover below.

How blackout curtains work and their limits

Blackout curtains use a tightly woven fabric, often with a foam or rubber backing layer, to physically block light from passing through. A good pair rated for blackout use will stop roughly 95 to 99 percent of light coming through the fabric itself, according to manufacturer testing most brands publish on their product pages.

The catch is that fabric coverage is only part of the equation. Light still sneaks in around the edges, especially at the top where the curtain meets the rod, and along the sides if the panel isn't wider than the window frame. We've measured light leakage in customer homes where the curtain fabric itself blocked light well, but a two-inch gap at the top let in enough glow to light up a phone on the nightstand.

To get closer to full coverage, you generally need:

• Panels at least 4 to 6 inches wider than the window frame on each side
• A curtain rod mounted higher and wider than the window itself, not just inside the frame
• Side channels or velcro strips if you want to seal the edges completely
• A double layer, sometimes a sheer curtain plus a blackout layer, for rooms with intense sun exposure

Even with all that, blackout curtains don't help at all if you're sleeping somewhere other than your bedroom, like on a plane, in a hotel room with thin curtains already installed, or camping. They also don't stop light from a partner's reading lamp or a TV left on across the room. They block outside light, not indoor light.

How sleep masks work and their limits

A sleep mask covers your eyes directly, so it doesn't matter what's happening in the room. This makes it the more portable and more universally effective option in terms of raw light blocking, since there's no gap for outside light to sneak around once the mask is seated properly on your face.

The limits here are more physical than optical. Cheap masks with a single elastic strap tend to shift during the night, especially if you sleep on your side, which creates gaps around the nose or temples exactly like the edge-leak problem with curtains. Contoured masks with molded eye cups solve this better because they sit off the eyelids entirely, but they cost more, usually in the 20 to 40 dollar range compared to 5 to 10 dollars for a basic flat mask.

Comfort is the other real limiter. Some people find any pressure on the eyes irritating, and masks can trap heat or cause the strap to dig into the head after a few hours. We've had customers tell us they wake up with a headache after using a tight mask overnight, which usually means it's time to loosen the strap or size up. If discomfort or headaches persist regularly, it's worth mentioning to a doctor rather than just switching brands repeatedly.

Materials matter too. Silk and satin masks slide less against skin and don't tug on eyelashes the way rougher cotton blends can. Foam-based contoured masks last longer structurally but can flatten out after 6 to 12 months of regular use, at which point they stop sealing well and need replacing.

Comparing cost, comfort, and setup

Here's how the two options stack up on the practical factors that actually affect whether you'll stick with them.

Curtains are a one-time investment per window that keeps working night after night without you having to remember to put anything on. Masks require zero installation but do require you to actually wear them correctly every single night, which is where a lot of people quietly give up after a week.

Which option suits which situation

If you own your home and sleep in the same room every night, blackout curtains are usually the better long-term investment. You install them once, and they work whether you're awake reading or fast asleep. They also block a small amount of outside noise and help with room temperature by insulating the window, which a mask obviously can't do.

If you travel often, share a room with someone who keeps different hours, or live with a landlord who won't allow drilling for curtain rods, a sleep mask is the more practical choice. It travels in a carry-on, works in a hotel room with paper-thin curtains, and doesn't care if your partner turns on a lamp at 11 p.m.

Shift workers sleeping during the day often need more than either option alone can provide, since daylight is far more intense than nighttime ambient light. In these cases, we usually recommend combining a well-fitted blackout curtain with a contoured sleep mask as a backup layer, particularly for anyone whose work schedule rotates and doesn't allow time to fully block out a room properly.

Parents of young children face a slightly different problem: kids often resist wearing anything on their face, which makes masks impractical, so blackout curtains tend to be the more realistic option for a child's room regardless of cost.

When it makes sense to use both

Using both isn't overkill in every case, it's often the most reliable setup for people who are genuinely sensitive to light or who deal with unusually bright environments. City apartments facing a lit-up street, rooms with east-facing windows in summer, and anyone recovering from jet lag can benefit from stacking both layers rather than relying on one.

The combination also gives you flexibility. On nights when your curtains are doing their job well, you can skip the mask. On a night when you're staying somewhere unfamiliar, or when a partner needs a light on to read, the mask still gets the job done without you needing to negotiate over the lamp.

We'd suggest starting with whichever option addresses your biggest pain point first, then adding the second layer only if you're still waking up earlier than you'd like or struggling to fall asleep despite the first fix. There's no need to buy both on day one if a 40 dollar curtain panel solves the problem on its own.

Common mistakes

• Buying curtain panels the exact width of the window instead of sizing up, which leaves light gaps on both sides
• Mounting the curtain rod inside the window frame instead of above and beyond it
• Choosing a flat sleep mask when you sleep on your side, where gaps form around the nose almost immediately
• Assuming a higher price always means better blackout performance, when fit and installation matter just as much as fabric quality
• Sticking with a mask that causes headaches or eye pressure instead of trying a contoured style or a looser strap

Next steps

Start by noticing where light actually gets in. Stand in your dark bedroom at night and look for any glow around the window edges or from devices in the room. That tells you whether your real problem is outside light, which curtains solve, or indoor light and travel situations, which a mask handles better.

If you go with curtains, measure your window width and add at least 8 to 12 inches total for rod placement before you buy. If you go with a mask, expect to try one or two styles before finding one that doesn't shift or press uncomfortably, and don't be afraid to size up if the first one feels tight. And if light sensitivity is part of a larger pattern of poor sleep that doesn't improve with these changes, it's worth talking to a doctor rather than assuming the room is the only issue.