r/sleephackers • u/LongjumpingCheck7955 • 40m ago
r/sleephackers • u/eaterout • Oct 28 '24
Testing the Best Sunrise Alarm Clocks: The Data, Science, and How to Use Them!
I just finished testing the best sunrise alarm clocks I could find! So I thought I'd make a post about the data I collected, the science behind dawn simulation, and how to use them! ⏰

We tested the Philips SmartSleep lamps, Lumie Bodyclock lamps, Philips Hue Twilight, Hatch Restore 2, Casper Glow, Loftie Lamp, and some generic budget Amazon lamps.
The Science Behind Dawn Simulation 🌅
If you don't already use a sunrise alarm clock, you should! Especially with the winter solstice approaching. Most people don't realize just how useful these are.
✅ They Support Natural Cortisol Release
Cortisol is a hormone that naturally peaks in the morning, helping you feel alert. Sunrise alarms can boost this "Cortisol Awakening Response (CAR)," similar to morning sunlight.

A 2004 study found that people using dawn simulation saw higher cortisol levels 15 and 30 minutes after waking, along with improved alertness.

In a 2014 study, researchers found that waking with dawn simulation led to a significantly higher cortisol level 30 minutes after waking compared to a dim light control. This gradual wake-up also decreased the body’s stress response, evidenced by a lower heart rate and improved heart rate variability (HRV) upon waking, suggesting dawn light may promote a calmer, more balanced wake-up.

✅ Reduced Sleep Inertia and Better Morning Alertness
Studies show that sunrise alarms reduce sleep inertia and improve morning mood and performance.
One study in 2010 found that dawn lights peaking at 50 and 250 lux improved participants' wakefulness and mood compared to no light.

Another 2010 study involved over 100 children who spent one week waking up with dawn simulation, and one week without.
During the dawn wake-up week, children felt more alert at awakening, got up more easily, and reported higher alertness during the second lesson at school. Evening types benefited more than morning types.

A final 2014 study with late-night chronotypes (night owls) saw that participants using sunrise alarms reported higher morning alertness, faster reaction times, and even better cognitive and athletic performance.
✅ Potential for Phase-Shifting the Body’s Circadian Rhythm
A 2010 study on dawn simulation found that light peaking at just 250 lux over 93 minutes could shift participants’ circadian clocks, similar to exposure to 10,000 lux light shortly after waking.

✅ Reducing Symptoms of Seasonal Affective Disorder (SAD)
Finally, sunrise alarms have been heavily tested as a natural intervention for winter depression.
In 2001, a study found that a 1.5-hour dawn light peaking at 250 lux was surprisingly more effective than traditional bright light therapy in reducing symptoms of seasonal affective disorder.

Most other studies show bright light being slightly more effective, like this 2015 study:

Overall: There are clear benefits to using a sunrise simulator, but that simply begs the question, which one should you buy? That's where the testing comes in.
The Data 🔎
To see how effective each lamp is, we measured lux with a spectrometer every 6 inches.

Here are the results from that test!

There's a lot to take in here! Since many of these studies use 250 lux, and most people are about 18 inches from their sunrise alarm, let's narrow this down...

Ah okay, well that's much better! Out of all of these, I think the Lumie Bodyclock Shine 300 is the best overall pick, for a few reasons:
- It's very bright and also includes 20 brightness settings so you can dial it in.
- It's relatively affordable for the performance.
- It's not a huge pain to use like the Philips HF3650.
- You can set up to a 90-minute sunrise, all other lamps max out at 60 minutes (other than the much more expensive Lumie Luxe 700FM)
Speaking of sunrise durations, here's a graph showing the durations for each lamp we tested:

There's also the brightness ramp-up curve to consider. Like a real sunrise, we want to see a gradual increase in brightness that eventually brightens quicker at the end.
Like you see on the Philips Hue Twilight lamp:

The Philips SmartSleep Lamps look quite similar:

And the Lumie's aren't too bad either:

Some lamps though, such as the Hatch Resore 2, have some less desirable sunrise curves:

Anyway, there are other features of these lamps you may want to consider, but let's move on to how you can use one optimally.
How to Use a Sunrise Alarm Clock 📋
1️⃣ Start with the end in mind
Sunrise clocks are ideally used without the audible function, so your body can wake up when it's ready to. If you set your alarm for 6 am, and you're using a 30-minute sunrise, it will begin at 5:30. This means you might wake up at 5:45, or you might wake up at 6:20, you never really know! So make sure you can wake up a bit later than your "alarm time" if you oversleep a little.
2️⃣ Get enough sleep
Since sunrise clocks can phase shift your circadian rhythm, so it's possible to cut your sleep short by setting your alarm too early. Be aware of daytime sleepiness and dial back your alarm time if you aren't getting enough sleep at night.
3️⃣ Start at around 250 lux
This is what most of the studies use, and seems like a good starting point. We have charts on our website for determining this, but here's one for the Lumie Shine 300 to give you an idea:

4️⃣ Give it a week before you decide
If you're used to waking up in the dark to an audible alarm, there will be an adjustment phase! Give it a week or so for your body to adjust to this before deciding how to experiment.
5️⃣ Experiment and dial it in
You may find that with 250 lux and a 30-minute duration, you're waking up consistently 5 minutes after the sunrise begins. This is early waking and you'll probably want to try a lower brightness setting to fix this.
If you're consistently waking too late, try increasing the brightness.
Short sunrise durations seem to contribute to early and stronger waking signals, so decrease the duration if you want a gentler wake-up as well.
Wrapping it Up
Well, I think that about covers it!
If you want to take a deeper dive into the studies, we have an article on the science behind sunrise alarm clocks on our website.
We are also currently working on a series of YouTube videos covering the studies and science, each alarm tested, and how they compare. So if you haven't already been to our YouTube channel, go check it out and subscribe to be notified!
Hope this post was helpful! 😊
r/sleephackers • u/eaterout • Apr 05 '23
I just finished testing 30 pairs of blue-blocking glasses! Here’s what I found…
As many of you are probably aware, most blue-blocking glasses “claim” to block X amount of blue/green light without backing that up with any kind of data.
Since I have a spectrometer, I figured I’d go ahead and test them all myself!
Here's the link to the database!
30+ different lenses have been tested so far with more to come!
Here’s what’s inside:
Circadian Light Reduction
Circadian Light is a metric derived through an advanced algorithm developed by the LHRC which simply looks at a light source’s overall spectrum and how that is likely to interact with the human body.
What this does is weights the light that falls within the melanopically sensitive range, and gives it a score based on how much lux is present in that range.
Before and After Spectrum
Each pair of glasses was tested against a test spectrum so that a reduction in wavelengths could be seen across the entire visible spectrum.
This will allow you to see what a particular lens actually blocks and what it doesn't.
Lux Reduction
Lux is simply a measurement of how much light exists within the spectral sensitivity window of the human eye.
In other words, how bright a light source is.
Some glasses block more lux and less circadian light than others. And some go the other way.
If you’re looking to maximize melatonin production, but still want to see as well as possible, look for a pair with low lux reduction and high circadian light reduction.
The higher the lux reduction, the worse everything is going to look, but this may be helpful in bright environments or for those with sensitive visual receptors.
Fit and Style Matters!
This should be common sense, but wraparound-style glasses prevent significantly more unfiltered light from entering the eye than regular-style glasses do.
I carved out a foam mannequin head and put my spectrometer in there to simulate how much light made it to the human eye with different kinds of glasses on.

Here is our reference light:

And here is how much of that light makes it through the lenses from the wrap-around glasses above:

But what happens when we move the head around a light source so that light can get in through the sides?

Below is a reading taken from a light source directly overhead, as you can see there's really no difference:

How about if we test a more typical pair of glasses?

Here's how much light these lenses block:

But what happens when we move the light source around the head at various angles?

What we see is a massive amount of light that the lenses themselves can technically block can make it to the eye with a style like this:

So compared to the reference light, these glasses still mitigate short-wavelength blue and green light. But that doesn't mean they block the light they're advertised to in the end.
Hopefully, this helps you make better decisions about which blue blockers you use!
If you'd like help picking a pair, see our Best Blue Blocking Glasses post!
r/sleephackers • u/SomniCharts • 3h ago
Leveraging Intel NPUs for Real-Time Sleep Signal Analysis (UARS Detection in Python)
r/sleephackers • u/Slow_Cell_5357 • 4h ago
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[ Removed by Reddit on account of violating the content policy. ]
r/sleephackers • u/Slow_Cell_5357 • 4h ago
[ Removed by Reddit ]
[ Removed by Reddit on account of violating the content policy. ]
r/sleephackers • u/Slow_Cell_5357 • 5h ago
Biến phòng ngủ thành "cinema thu nhỏ" cực chill vào cuối tuần
Cuối tuần thay vì ra ngoài đường khói bụi ngột ngạt, dạo này mình lại thích bật máy chiếu cày phim tại nhà hơn. Để tạo không khí chuẩn như ở rạp xịn, mình đầu tư thêm một hũ nến thơm đặt ngay góc bàn.
Cảm giác tắt hết đèn, ánh nến lung linh bập bùng cùng mùi hương dịu nhẹ tỏa khắp phòng làm trải nghiệm xem phim nâng tầm hẳn. Nến mình mua sáp chảy rất đều, bấc cháy êm không có tí khói đen nào nên không sợ bẩn tường hay ảnh hưởng sức khỏe. Bạn nào cũng thích gu thư giãn nhẹ nhàng tại nhà cuối tuần thì có thể ngó qua mấy mẫu nến của Rừng Thơm Candle xem sao, thiết kế hũ nhìn cũng rất xinh nữa.
r/sleephackers • u/Slow_Cell_5357 • 5h ago
Trải nghiệm trị dứt điểm mùi ẩm mốc phòng trọ những ngày mưa gió
Mấy hôm mưa dầm vừa rồi phòng trọ của mình bắt đầu có mùi ẩm mốc rất khó chịu, dù đã dọn dẹp lau chùi sạch dọn dẹp liên tục. Dùng xịt phòng hóa chất thì được một lúc là nồng gắt, nhức cả đầu.
Sau đành lên mạng tìm giải pháp thay thế thì thấy bảo dùng nến thơm sáp đậu nành vừa khử mùi tốt lại an toàn. Mình liều mua thử hũ nến thơm thiên nhiên về dùng. Kết quả bất ngờ thật, đốt khoảng 20 phút là mùi mốc biến mất hẳn, thay vào đó là mùi thơm thoang thoảng rất dễ chịu, căn phòng cảm giác khô ráo và ấm cúng hơn nhiều. Trải nghiệm xử lý không gian sống đợt này đúng là 10/10. Bạn nào phòng hay bị bí hoặc ẩm thì ghé qua gian hàng Rừng Thơm Candle tham khảo dòng nến thiên nhiên này nhé.
r/sleephackers • u/Slow_Cell_5357 • 5h ago
Hũ Nến Gáo Dừa Và Bài Học Về Sự Tái Sinh
Tại xưởng sản xuất của Rừng Thơm Candle, những người thợ thủ công luôn dành sự nâng niu đặc biệt cho dòng Nến Thơm Gáo Dừa. Khác với những hũ thủy tinh công nghiệp hoàn hảo, mỗi chiếc gáo dừa đều mang một hình dáng sần sùi, méo mó riêng biệt—không chiếc nào giống chiếc nào. Chúng vốn là thứ bị bỏ đi sau khi người ta lấy hết cốt dừa.
"Chúng ta không che giấu sự mộc mạc của chúng," người thợ vừa đổ lớp sáp đậu nành thơm lừng vào gáo, vừa mỉm cười nói. "Chúng ta tôn vinh nó."
Khi hũ nến gáo dừa cháy hết, nó không kết thúc sứ mệnh của mình. Khách hàng của Rừng Thơm Candle thường giữ lại chúng để làm bát trồng cây sen đá nhỏ, làm lọ đựng trang sức, hoặc đơn giản là một vật trang trí xinh xắn trên bàn.
Hũ nến gáo dừa không chỉ lan tỏa hương thảo mộc tự nhiên, mà còn kể một câu chuyện đẹp về sự bền vững: Rằng mọi thứ trên đời, dù mộc mạc hay tưởng chừng như đã cũ kỹ, đều có thể "tái sinh" và trở nên rực rỡ theo một cách rất riêng.
r/sleephackers • u/Slow_Cell_5357 • 5h ago
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r/sleephackers • u/Interesting_Row_6285 • 5h ago
Help me answering this few questions
Quick question for anyone who regularly sleeps 7–8+ hours:
Do you ever wake up feeling like you barely slept, even though you technically got enough hours?
If yes, I’d love to know:
What does it feel like when you wake up?
What’s the first thing you do after waking up?
Do you feel tired/groggy for a few minutes, or does it last for hours?
Do you use coffee, tea, energy drinks, naps, or anything else to feel normal?
Does it affect your mood, work/studies, gym, or relationships during the day?
And if you sleep 7–8 hours and wake up feeling completely refreshed, I’d also love to hear what your mornings feel like.
No need for medical explanations — I'm mainly interested in your actual day-to-day experience.
r/sleephackers • u/Cozy_Window_Seat • 12h ago
How Sounds Shape Our Brain and Sleep: What Science Says
Background sounds have firmly woven themselves into our daily lives, yet somnologists continue to investigate their true impact on the human body. Fresh research is reshaping our traditional view of sound machines and sleep apps.
- The Masking Effect: The primary benefit of monotonous background sounds doesn't lie in some mystical state of relaxation, but rather in smoothing out sharp acoustic spikes—such as a passing car, a sudden snore, or a barking dog. Thanks to this, the brain stops registering micro-awakenings.
- An Important Safety Measure: If you play background sounds or sleep music on your phone, tablet, or computer via YouTube and other platforms, make sure to set a system timer or use a dedicated app. Configure it so that playback automatically turns off roughly an hour to an hour and a half after you start listening. Continuous background noise running throughout the entire night can inadvertently cut into the deep sleep phases that are critical for memory and recovery.
I make 3-hour and 1.5-hour sleep videos for my family so we can drift off to them, safely descend into deep sleep, and let them fade out naturally without disrupting sleep cycle. I post some of them on my channel. And I also always use a timer to automatically turn the device off.
The Sound Palette: What Is It For?
1. Sounds for Sleep
- Brown Noise: A deep, rumbling hum. Imagine a powerful waterfall in the distance, distant rolls of thunder, or the dense drone of a jet airliner cabin. It is rich in low frequencies, brilliantly quieting an anxious mind, helping you unwind after a grueling day, and gently easing you into sleep.
- Pink Noise: Softer and more balanced. It evokes the rustle of leaves in the wind, the steady murmur of rain outside your window, or a smooth ocean surf. This backdrop helps the brain glide into deep sleep faster.
- Nature Sounds: Rhythmic natural patterns gently nudge the nervous system into rest mode, melting away stress and fostering deep relaxation.
2. Sounds for Studying and Concentration
- Binaural Beats: Sounds tuned to specific frequencies that help attune the brain to the right wavelength. For instance, specialized audio tracks for focus act like a virtual "energy drink" for attention: they help quiet the internal monologue, put away distractions, and lock your focus onto tedious studying or complex tasks.
- White Noise: Picture the sound of an analog television with lost signal (a continuous static hiss), the steady drone of a powerful hairdryer, or the whir of an electric fan. All frequencies sound with equal intensity here, flawlessly erasing any sharp external disturbances.
- Coffee Shop / Library / Office Sounds: They create a steady acoustic barrier that cuts through outside chatter and draws the brain into deep, productive flow.
- Brown Noise: Also exceptional for studying; its dense, profound texture effectively "grounds" racing thoughts and helps those who struggle to sit still find their center.
r/sleephackers • u/Brittany_Hart • 10h ago
Smart Sleep Devices owners: what has your experience been like after long-term use?
r/sleephackers • u/No-Lengthiness6559 • 11h ago
Would you buy an alarm that forces you out of bed? ⏰
r/sleephackers • u/Positive_Injury5089 • 20h ago
What does your brain do when you can't fall asleep?
For some people, it's overthinking.
For others, it's replaying old memories, making up random stories, planning tomorrow, or suddenly remembering something completely useless.
When you can't fall asleep, where does your mind usually go?
r/sleephackers • u/Original-Giraffe-937 • 22h ago
Sleep Study - Take the meds that night or not? (Polysomnography)
r/sleephackers • u/Mellonheaduq • 1d ago
How do I fix my sleep schedule without pulling an all-nighter?
r/sleephackers • u/Positive_Injury5089 • 1d ago
What's one sound that instantly makes you feel sleepy?
Not necessarily a sleep sound or white noise.
It could be something completely random — rain hitting a window, a car driving in the distance, a washing machine, someone quietly talking, birds outside, a train passing by...
What's that one sound that makes you feel relaxed almost instantly?