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  • Poor sleep can contribute to a whole host of chronic health problems, from obesity and diabetes to immune problems and an increased risk for cancer. Plus, it raises your risk of accidents and occupational errors
  • Two of the largest contributors to poor sleeping habits are the use of artificial lighting and electronics at night, and insufficient light exposure during the day
  • To optimize sleep, get sun exposure first thing in the morning, and/or again around noontime. In the evening, avoid blue light. Blue-blocking glasses are a simple remedy. Also make sure to sleep in darkness

How Blocking Blue Light at Night Can Help Transform Your Sleep

May 05, 2016 | 264,954 views
| Available in EspañolDisponible en Español

By Dr. Mercola

Do you get the recommended eight hours of uninterrupted, restful sleep every night? Many don't, and in my experience, if you're not sleeping well, it's virtually impossible to stay healthy and emotionally balanced.

Over the long term, skimping on sleep can contribute to a whole host of chronic health problems, from obesity and diabetes to immune problems and an increased risk for cancer. Additionally, it raises your risk of accidents and occupational errors.

Prior to light bulbs, people slept an average of 10 hours a night. Nowadays, the average American gets less than seven hours of shut-eye. Why is that? As noted by Authority Nutrition:1

"It turns out that perhaps the single biggest contributor to our collective sleep problems is the use of artificial lighting and electronics at night. These devices emit light of a blue wavelength, which tricks our brains into thinking that it is daytime."

A related part of this problem is the fact that most people work indoors and fail to get sufficient exposure to full, bright, and natural sunlight during the day. This disconnect from the natural cycles of day and night can turn into a chronic problem where you're constantly struggling to fall asleep and stay asleep.

Fortunately the remedy is both simple and inexpensive, as all you have to do is modify your light environment to resynchronize your body to the natural cycles of light and dark.

Step 1: To Sleep Well, Get Bright Light Exposure During the Day

Light intensity is measured in lux units, and on any given day, the outdoor lux units will be around 100,000 at noon. Indoors, the typical average is somewhere between 100 to 2,000 lux units — some two orders of magnitude less.

So when you spend all or a majority of your day indoors, you essentially enter a state of "light deficiency." The reason why light intensity is important is because it serves as the major synchronizer of your master body clock, which is composed of a group of cells in your brain called the suprachiasmatic nuclei (SCN).

These nuclei synchronize to the light-dark cycle of your environment when certain wavelengths of light enter your eyes. You also have other biological clocks throughout your body, and those clocks in turn synchronize to your master clock.

So, if you want to get good sleep, you have to have properly aligned circadian rhythms, and step No. 1 is to make sure you get a sufficient dose of bright light exposure during the daytime.

Your pineal gland produces melatonin roughly in approximation to the contrast of bright sun exposure in the day and complete darkness at night. If you're in darkness all day long, your body can't appreciate the difference and will not optimize melatonin production.

Ideally, to help your circadian system reset itself, get at least 10 to 15 minutes of light first thing in the morning. This will send a strong message to your internal clock that day has arrived, making it less likely to be confused by weaker light signals later on.

Then, around solar noon, get another "dose" of at least 30 minutes' worth of sunlight. A full hour or more would be even better. If your schedule is such that you have to get up and arrive at work before sunrise, aim to get at least that half hour of bright light sometime during the day.

A gadget that can be helpful in instances when you absolutely cannot get outside during the day is a blue-light emitter. Philips makes one called goLITE BLU. (You can find it on Amazon for less than $150.)

It's a small light therapy device you can keep on your desk. It's especially useful during winter when light intensity can be low even during daytime. Using it twice a day for about 15 minutes can help anchor your circadian rhythm when you can't get outside.

Step 2: Avoid Blue Light at Night

Normally, your brain starts progressively increasing the hormone melatonin around 9 or 10 pm, which makes you sleepy. Melatonin acts as a marker of your circadian phase or biological timing.

In a nutshell, this hormone influences what time of day or night your body thinks it is, regardless of what time the clock on the wall displays. Besides regulating your sleep cycle, it also provides other important health benefits, including helping to prevent cancer.

Somewhere between 50 and 1,000 lux is the activation range within which light will begin to suppress melatonin production. However, wavelength is also important. Red and amber lights will not suppress melatonin, while blue, green, and white lights will.

The reason for this is because these are the wavelengths that are the most common outdoors during daytime hours. So step No. 2 is to avoid the blue light wavelength after sunset. This includes artificial light, and light emitted by electronics such as your TV, computer, and other electronic screens.

The blue light range (400 to 490 nm) can also induce photoreceptor damage in your eyes, so besides disrupting your sleep this is another potential problem with light emitting screens.

As noted in one recent study,2 "it is important to consider the spectral output of LED-based light sources to minimize the danger that may be associated with blue light exposure."

Ways to Limit Blue Light Exposure at Night

There are a number of ways to avoid blue light in the evening depending on your lifestyle and personal preferences:

1. Turn off or dim all lights after sunset, and avoid watching TV or using light emitting electronics for at least one hour before bedtime (ideally two hours or more). Research3,4 shows that using an electronic device within one hour of bedtime can delay falling asleep for more than an hour.

Another study5 that compared melatonin profiles in individuals exposed to standard room light (<200 lux) vs. dim light (< 3 lux) found that exposure to room light before bedtime shortened the time of elevated melatonin levels by about 90 minutes. That means it may take you an extra hour and a half before you're sleepy enough to fall asleep once you're in bed. Combine room light and electronic displays right before bed and it's easy to see how sleep may remain elusive for hours on end.

2. After sundown, shift to a low-wattage bulb with yellow, orange or red light if you need illumination. A salt lamp illuminated by a five-watt bulb is an ideal solution that will not interfere with your melatonin production. If using a computer or smart phone, install blue light-blocking software like f.lux. The program automatically alters the color temperature of your screen as the day goes on, pulling out the blue wavelengths as it gets late.

3. The easiest solution, which I recently started using myself, is to simply use amber colored glasses that block blue light. Studies6,7,8 have confirmed that when using blue-blocking glasses, people produce as much melatonin as they do in dim light, even if they're in a lit room or using light emitting technology.

Other studies9 have shown that people using blue-blocking glasses had major improvements in both sleep quality and mood. Shift workers who use them before bedtime (i.e. in the morning when it's bright out) also report improved sleep.10

I found a Uvex model (S1933X) on Amazon that costs less than $10.11 Most blue-blocking glasses sell for around $90, so they're a fantastic bargain — far less expensive than buying blue-blocking light bulbs as well. With their sporty frame, they also look better than many other models.

These are the ones I use, and they work like a charm to eliminate virtually all blue light. This way, you don't have to worry about installing programs on all your devices, or buying special light bulbs for evening use. Once you have your glasses on, it doesn't matter what light sources you have on in your house.

I typically put them on around dusk, which at this time of year is around 8:30 pm. But if you already struggle with sleep issues it would probably be wise to put them on even earlier, especially if your light exposure during the day has been limited. I take a one-hour walk every day in the bright sunlight on the beach, so along with boosting my vitamin D, I also anchor my circadian rhythm at the same time and I rarely ever have trouble sleeping.

Step 3: Sleep in Darkness

Last but not least, when it's time to go to sleep, make sure your bedroom is as dark as possible. Exposure to room light during sleep has been shown to suppress melatonin by more than 50 percent,12 but even a small amount of light can decrease your melatonin, making sleep more elusive. Simply closing your eyes is not enough as light can penetrate your eyelids.

You may want to invest in blackout shades as they are really worth the investment. A sleep mask can also do the trick and is much less expensive. It is what I always carry when traveling, as some hotels don't have black out systems that work. Also keep in mind that digital alarm clocks with blue light displays could have a detrimental effect, so either swap out your clock, or cover the display.

Other Tips to Improve Your Sleep

Small adjustments to your daily routine and sleeping area can go a long way toward ensuring you uninterrupted, restful sleep — and thereby better health. The most important steps to help you resynchronize your circadian clock have been detailed above. If you're still having trouble sleeping, you may need to make a few more changes.

Some of the more common issues are listed in the table below. For even more helpful guidance on how to improve your sleep, please review my "33 Secrets to a Good Night's Sleep."

Address mental states that prevent peaceful slumber

A sleep disturbance is always caused by something, be it physical, emotional, or both. Anxiety and anger are two mental states that are incompatible with sleep.

Feeling overwhelmed with responsibilities is another common sleep blocker. To identify the cause of your wakefulness, analyze the thoughts that circle in your mind during the time you lie awake, and look for themes.

Many who have learned the Emotional Freedom Techniques (EFT) find it is incredibly useful in helping them to sleep. One strategy is to compile a list of your current concerns, and then "tap" on each issue. To learn how to tap, please refer to our free EFT guide.

Keep the temperature in your bedroom below 70 degrees Fahrenheit

Many people keep their homes too warm at night. Studies show that the optimal room temperature for sleep is between 60 and 68 degrees Fahrenheit.

Take a hot bath 90 to 120 minutes before bedtime

This raises your core body temperature, and when you get out of the bath it abruptly drops, signaling your body that you're ready for sleep.

Be mindful of electromagnetic fields (EMFs) in your bedroom

EMFs can disrupt your pineal gland and its melatonin production, and may have other detrimental biological effects.

A gauss meter is required if you want to measure EMF levels in various areas of your home. Ideally, you should turn off any wireless router while you are sleeping — after all, you don't need the Internet when you sleep.

Develop a relaxing pre-sleep routine

Going to bed and getting up at the same time each day helps keep your sleep on track, but having a consistent pre-sleep routine or "sleep ritual" is also important.

For instance, if you read before heading to bed, your body knows that reading at night signals it's time for sleep.

Sleep specialist Stephanie Silberman, Ph.D. suggests listening to calming music, stretching or doing relaxation exercises.13 Mindfulness therapies have also been found helpful for insomnia.14

Avoid alcohol, caffeine and other drugs, including nicotine

Two of the biggest sleep saboteurs are caffeine and alcohol, both of which also increase anxiety. Caffeine's effects can last four to seven hours.

Tea and chocolate also contain caffeine. Alcohol can help you fall asleep faster, but it makes sleep more fragmented and less restorative.

Nicotine in all its forms (cigarettes, e-cigs, chewing tobacco, pipe tobacco, and smoking cessation patches) is also a stimulant, so lighting up too close to bedtime can worsen insomnia. Many other drugs can also interfere with sleep.

Use a fitness tracker to help you get to bed on time, and track which activities boost or hinder deep sleep

To optimize sleep you need to go to bed early enough. If you have to get up at 6:30 am, you're just not going to get enough sleep if you go to bed after midnight.

Many fitness trackers can now track both daytime body movement and sleep, allowing you to get a better picture of how much sleep you're actually getting.

Newer fitness trackers like Jawbone's UP3 can even tell you which activities led to your best sleep and what factors resulted in poor sleep.

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