Red Light At Night: How Does It Affect Your Sleep And Vision?

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Does Red Light at Night Help or Hinder Your Sleep?

Medically reviewed by Alana Biggers, M.D., MPH — Written by Ann Pietrangelo on February 12, 2021

Facts about red light
Light to avoid at night
Light and sleep
Summary

You probably know that bright lights and the blue glow of electronics at night can hinder your sleep. Well, it turns out that red light may also affect your sleep, but in a potentially helpful way.

In this article, we’ll examine how red light at night may affect your sleep cycle and what you can do to improve your sleep pattern.

What’s known about red light’s effects at night?

The type of red light that affects your sleep is light that emits red light wavelengths — not simply light bulbs that are tinted red.

While red-tinted light bulbs can be quite soothing and put you in a good mood, they may not be efficient for red light therapy. Because of this, they likely won’t have the same effect on your sleep.

Red light and sleep

The theory is that red light wavelengths stimulate the production of melatonin. Melatonin is a naturally occurring hormone that helps you sleep. Your brain releases more melatonin as darkness falls and tends to release less when you’re exposed to light.

In a small 2012 study, researchers evaluated the effect of red light therapy on 20 female athletes. Participants were randomly assigned to receive 30 minutes of red light therapy every night for 14 days.

When compared to a placebo group that didn’t have light therapy, participants had improved sleep quality, melatonin levels, and endurance performance.

Research published in 2019 detailed a 3-week study of 19 people in an office environment. The researchers found that using a combination of red and ambient white light in the afternoon improved circadian rhythm and increased alertness in the period after lunch, when many people have a dip in their energy level.

A very small 2017 study found that color is closely related to the ability to fall asleep. The researchers also noted that personal preference may affect which color is likely to help you fall asleep.

While the research is promising, more large-scale studies are needed to more fully understand how red light affects sleep.

Red light and sleep inertia

Sleep inertia is that groggy feeling that lingers after you wake up. It can affect your short-term memory, alertness, and overall performance.

One small 2019 study on sleep inertia showed that saturated red light delivered through closed eyelids, at levels that don’t suppress melatonin, may help ease sleep inertia upon waking.

Red light and night vision

The glare from bright white light at night can leave you squinting and straining to see clearly. Red light is non-glaring, so it can help you see better at night.

That’s why you’ll find red lights in airplane cockpits and submarines, and why astronomers and stargazers like to carry red flashlights.

What color light should you avoid at night?

Some types of light are more likely to disturb your circadian rhythm than others. But keep in mind that any type of light can disturb your sleep if it’s bright enough or shining into your face.

Blue light is a good thing during the day. Once you wake up, it can help you feel more alert. But at night, blue light can make it harder to fall asleep and stay asleep. That’s because blue light wavelengths can stop your brain from producing melatonin, the hormone that helps you feel sleepy.

Blue light waves are emitted from the sun, as well as from:

fluorescent lights
LED lights
televisions
cell phones and tablets
computer screens
other electronic screens, like gaming devices

If you’re having sleep problems, try eliminating blue light and bright light as it gets closer to your bedtime.

Turn off the TV and put away phones, tablets, and laptops at least 30 minutes before you head to bed. Also, try to slowly dim your household lighting in the evening once the sun sets.

How does light affect your sleep?

Light plays a key role in your circadian rhythm and how well you sleep.

Your circadian rhythm is your internal 24-hour clock. It helps you feel sleepy at night when it’s dark and it also makes you feel alert during daylight hours.

Light exposure provides your brain with information that guides your circadian rhythm. In a natural light pattern, your circadian rhythm follows sunrise and sunset. But our world is filled with artificial sources of light that can throw us off this natural cycle.

Several studies suggest that light exposure at the wrong time can disrupt circadian rhythm and potentially impact your health.

When your circadian rhythm is off, you can end up in a vicious cycle. You can’t sleep well at night, and you feel tired and in need of a nap during the day.

But there are a few ways you can use light to help get your rhythm back.

At night:

If possible, block all light from your bedroom. Consider installing blackout curtains or using a sleep mask.
If you use a nightlight, choose one that emits dim red, orange, or yellow light.
Remove, power down, or use night mode on electronics that shine into your bedroom.
To really get back on track, avoid electronic screens for 30 minutes to an hour before going to bed.

During the day:

Open your window blinds when you wake up in the morning. Let the sunshine in as soon as you can, when possible.
If you must wake up before sunrise, turn on some low-wattage lights.
Expose yourself to natural light throughout the day to improve your alertness and mood.

In addition to lighting, you’ll want to take other sleep hygiene measures, like avoiding caffeine, alcohol, and vigorous exercise before bedtime.

If you have a sleep disorder that you can’t resolve, see your doctor to find out if there’s an underlying condition that should be treated.

Light therapy is an option for some people with sleep disorders, but it’s best to discuss this with your doctor first. It’s important to choose the right type of light box and to use it at the correct time of day.

The bottom line

Generally speaking, red light at night doesn’t seem to interfere with sleep like blue light does. In fact, it may actually improve your sleep. While more research is needed, the current evidence seems to indicate that red light at night doesn’t disturb sleep.

If you want to try red light for better sleep, choose products that emit red light wavelengths instead of bulbs that are simply tinted red. Also, try to expose yourself to sunshine and brighter lights in the daytime, dimmer lights in the evening, and darkness when it’s time to sleep.

Sleep problems can have an impact on both your physical and mental health. If your sleep issues continue, speak with your doctor to find out what your next steps should be.

How we reviewed this article:

SourcesHistoryHealthline has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical journals and associations. We only use quality, credible sources to ensure content accuracy and integrity. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.

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Medically reviewed by Alana Biggers, M.D., MPH — Written by Ann Pietrangelo on February 12, 2021

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