You’ve probably heard the common advice: “no screens before bed” or “blue light is bad for sleep.” But what does that really mean, and why should you care? Does blue light actually affect your sleep?
It’s easy to brush off advice if we don’t fully understand it—kind of like when our parents told us not to swim for 30 minutes after eating, but didn’t explain why. Without knowing the reasoning, we were more likely to ignore it.
But some advice, like “eat your veggies to stay healthy,” sticks with us because we eventually understand its value. Now, as adults, we know the importance of nutrition. My goal here is to give you that same “aha” moment about blue light so you’ll understand why avoiding screens before bed really can help you get better sleep.
How Our Eyes React to Light
Let’s start with a quick look at how light affects our eyes. You might know about rods and cones—the cells that help us see in low light and recognize color. But there’s another type of cell called intrinsically photosensitive retinal ganglion cells (don’t worry, you won’t need to say that five times fast!). These cells are highly sensitive to blue light—the type of light emitted from phones, tablets, and TVs.
When blue light hits these cells, it sends signals to the brain’s suprachiasmatic nucleus (SCN). The SCN is our body’s internal clock, managing our sleep-wake cycle.
Why Blue Light Disrupts Sleep: The Melatonin Connection
Here’s where it gets tricky: your body naturally produces melatonin, a hormone that helps you feel sleepy, when it starts to get dark. But blue light confuses your brain, making it think it’s still daytime, which delays melatonin production and makes it harder to fall asleep.
To make matters worse, our eyes become even more sensitive to light late at night and early in the morning. So if you’re scrolling through your phone or binge-watching TV before bed, that blue light is tricking your brain into staying alert. Even small lights—like the little blue LED on your charger—can disrupt your sleep, especially when you wake up briefly in the middle of the night.
Light our eyes used to be exposed to in the evenings The light our eyes encounter nowadays
The Modern Impact of Artificial Light on Sleep
It’s worth noting that this whole blue light issue is relatively new. Before modern lighting, our bodies were in sync with the natural light-dark cycle. People relied on sunlight during the day and the warm glow of fires, candles, or lamps at night. These light sources had longer wavelengths, which didn’t interfere with melatonin production.
But with today’s artificial lighting, especially from screens and LED lights, we’re constantly exposed to short-wavelength blue light. While it’s great for energy efficiency and productivity, it’s not doing our sleep any favors. The bright blue light from our screens mimics midday sunlight, which throws off our body’s natural rhythms and leads to sleep disturbances.
How Natural Light Cues Our Sleep-Wake Cycle
Throughout the day, the wavelengths of light we experience naturally change. The peak of blue light exposure happens around midday (Fun Fact, that’s why the sky appears blue). As the day progresses and the sun begins to set, the light has to travel through more of the Earth’s atmosphere. This filters out much of the blue light, leaving behind the longer wavelengths that create those beautiful pink, orange, and red hues we see at sunset.
When we see these warmer colors, our brain recognizes that it’s almost time for bed and starts producing melatonin. But nowadays, many of us miss out on those natural cues. Instead, we’re glued to our screens, soaking in artificial blue light that tells our brain, “Hey, it’s still daytime!” No wonder our internal clocks are confused.
Health Risks of Poor Sleep
Ignoring the impact of blue light and poor sleep doesn’t just make you feel groggy the next day—it can lead to serious health issues. Sleep deprivation has been linked to weight gain, as it throws off the balance of hunger hormones like ghrelin and leptin, making you more likely to crave unhealthy foods.
Lack of sleep is also a major risk factor for diabetes. Poor sleep affects your body’s ability to process glucose, which can lead to higher blood sugar levels and an increased risk of type 2 diabetes.
Sleep is critical for heart health as well. When you don’t get enough rest, it can raise blood pressure and cause inflammation, both of which increase the risk of heart disease. And let’s not forget how important sleep is for cognitive function. Memory, concentration, and decision-making all suffer when we don’t get enough rest.
So, when we let blue light mess with our sleep, we’re not just sacrificing a good night’s rest—we’re also putting our long-term health at risk.
Simple Tips to Reduce Blue Light Exposure
Don’t worry, you don’t need to banish screens entirely to get better sleep. Here are a few easy ways to reduce blue light exposure and help your body prepare for rest:
- Limit Screen Time Before Bed: Aim to stop using your devices at least an hour before bedtime. This gives your body time to start producing melatonin naturally.
- Turn on Night Mode: Most devices have a “night mode” that reduces blue light. Switch it on in the evening to minimize blue light exposure.
- Try Blue Light Glasses: If you need to use screens at night, blue light blocking glasses can help. Make sure they have an amber tint—those are more effective for promoting melatonin production.
- Adjust Your Lighting: In the evenings, use dim, warm-colored lights at home. Opt for table lamps over bright ceiling lights to create a more sunset-esque environment.
- Wind Down with Calming Activities: Replace screen time with relaxing activities like reading a book, meditating, or doing some gentle stretching. This tells your body it’s time to wind down. (You can read my wind down blog for more tips on this!)
Blue Light Really Does Affect Our Sleep!
So let’s do something about it!
In our screen-filled world, being mindful of blue light exposure is key to improving sleep. By understanding how our bodies respond to light and making small adjustments to our nighttime routines, we can improve sleep quality, protect our health, and wake up feeling refreshed. Let’s make restful sleep a priority—because we all deserve to wake up feeling our best.
Patti Read is the founder of Goldilocks Sleep Solutions. You can follow her on Facebook and Instagram.