Does Blue Light from Screens Suppress Melatonin and Disrupt Sleep?
Screens are a big part of life today. People use phones, laptops, TVs, and tablets for work, entertainment, and learning. Most people look at screens not only during the day, but also at night. This has raised an important question: Does blue light from screens affect sleep?
The short answer is yes. Screen light, especially blue light, can make it harder for your body to sleep. It affects melatonin, which is the body’s sleep hormone. Melatonin helps you feel sleepy at night. It also supports your body’s circadian rhythm, which is your natural 24-hour body clock.
When melatonin is low, your body does not feel ready to sleep. This is why using screens late at night may lead to sleeping problems.
What is Blue Light?
Blue light is a type of light that has short, high-energy waves. It comes from the sun, but also from screens and LED bulbs. During the day, blue light is helpful. It keeps you alert and awake. It also helps control your circadian rhythm by letting your body know it is daytime.
But at night, blue light confuses the body. It makes your brain think it is still day, even when it is dark outside. Because of this, your body stops making enough melatonin. This delay in melatonin is known as blue light melatonin suppression.
A study from
Harvard University showed that blue light reduces melatonin levels twice as much as green light. It also changed the body’s internal clock by up to 3 hours. This makes it harder for people to fall asleep at their usual time.
Why Melatonin and Circadian Rhythm Matter
Melatonin is released when it gets dark. This hormone tells your body it is time to slow down and get ready to sleep. It works together with your circadian rhythm, which controls sleep, wake times, and even hunger and body temperature.
When you use screens late at night, the blue light stops melatonin from rising. This causes the circadian rhythm to shift. You may feel wide awake at night and tired in the morning. Over time, this can affect your health, focus, mood, and energy.
A study published in the
NIH found that even regular room lighting combined with screens can drop melatonin levels by 50% or more. People exposed to this light in the evening had trouble falling asleep and reported feeling more tired during the day.
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What Happens When Melatonin Is Suppressed?
When melatonin stays low, your body cannot prepare for sleep properly. You may experience:
- Trouble falling asleep
- Light or broken sleep
- Waking up often at night
- Feeling tired in the morning
- Difficulty focusing during the day
In one study, people who used screens before bed took longer to fall asleep and had lower energy levels the next morning. Their sleep was also less deep, which means the body could not fully rest.
Even short periods of screen time before bed can affect sleep. Research by Physopedia shows that just 30 minutes of blue light exposure before bedtime is enough to delay the body's natural clock and reduce melatonin.
How to Reduce the Effects of Blue Light
You do not have to stop using screens completely. But you can follow simple steps to protect your sleep.
1. Use Blue Light Filters or Night Mode
Most phones today come with features like Night Shift (iPhone) or Night Light (Android). These tools reduce the blue light by making the screen look warmer or more yellow.
Studies by Healthline show that using a blue light filter in the evening can help protect melatonin and improve sleep quality. It is a simple change that makes a big difference over time.
2. Keep Screen Brightness Low
Bright screens even with filters can still affect the sleep hormone. Use low brightness in the evening. Avoid looking at screens in dark rooms where the light feels too strong.
3. Avoid Screens Before Bed
Try to stop using screens 1 to 2 hours before going to bed. This helps melatonin rise naturally. During this time, you can read a book, stretch, or listen to music. These quiet activities help your body relax and prepare for sleep.
The Sleep Foundation suggests that stopping screen use one hour before bed can help people fall asleep faster and wake up less often at night.
4. Use Warm Room Lighting
White or blue lights at home can also block melatonin. In the evening, turn off bright ceiling lights. Use lamps with warm yellow bulbs instead. This makes the room feel calmer and supports your circadian rhythm.
5. Silence Notifications
Notifications can keep your brain active. Use Do Not Disturb mode after a certain time. This helps your mind settle down and prevents you from checking your phone often.
6. Set App Limits or Sleep Schedules
Most smartphones include helpful tools:
- Digital Wellbeing (Android) lets you block apps and set sleep times.
- Screen Time (iPhone) lets you set app limits and schedule downtime.
These features stop late-night scrolling and help you stick to a regular sleep routine.
Check out the Jolt app How Jolt Can Help
Today’s digital time makes it easy to stay connected all the time, even late at night. But using screens without limits can affect your melatonin, confuse your circadian rhythm, and leave you feeling tired every day.
The good news is that you can still enjoy technology and protect your sleep. Use your phone’s built-in settings, change your lighting, and give your body time to relax at night. Small changes can help your sleep become deeper, stronger, and more refreshing.
If you need extra help,
you can try using Jolt. Jolt is a focus and habit-building app that helps you
manage screen time, block distractions, and reduce nighttime use. It supports healthy sleep by encouraging good digital habits and helping you stay off screens when it matters most.
With the right habits and tools, you can enjoy screen time during the day and sleep peacefully at night.
Frequently Asked Questions
1. What is melatonin, and why is it important for sleep?
Melatonin is a natural hormone made by the brain. It helps your body feel sleepy at night. When melatonin levels go up, your body knows it is time to rest. It plays a big role in your sleep cycle and helps you fall asleep on time.
2. Does blue light really affect melatonin levels?
Yes. Blue light from phones, TVs, and laptops can lower melatonin levels, especially at night. This makes it harder for your body to feel sleepy. Many studies show that blue light delays the sleep process and affects your natural sleep rhythm.
3. What is the circadian rhythm?
The circadian rhythm is your body’s 24-hour clock. It tells you when to sleep and when to wake up. It also controls other body functions. Blue light at night can shift your rhythm, making you sleep late and feel tired during the day.
4. Can using a blue light filter really help?
Yes. Using a blue light filter or “night mode” on your phone can help reduce the light that blocks melatonin. It changes the screen color to warm tones, which are better for your eyes and your sleep.
5. What is one easy way to improve sleep while still using a phone?
One easy way is to stop using screens at least 1 hour before bed. You can also use sleep tools on your phone, such as app limits or bedtime modes. These steps help protect your melatonin and improve your sleep quality.
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