How Blue Light Affects Sleep and Ways to Curb

By now, you’ve likely become conscious that indulging in the use of electronics – such as your phone, laptop, or tablet – during the hours prior to going to bed is far from an ideal habit. This is mainly because of the way blue light impacts your circadian rhythm.

Researchers hold the belief that light exposure during the night is a contributing factor to the numerous individuals who grapple with sleep deprivation and its consequent effects like weight gain, low energy levels, and depressive moods.

Perhaps you’re pondering, “Precisely what is the blue light on my phone?”

Below, we’ll delve into how blue light varies from other light wavelengths, the effects it has on your body – both beneficial and detrimental – and the straightforward methods through which you can manage your exposure.

What Is Blue Light?

Visible blue light constitutes the segment of the visible light spectrum that boasts the shortest wavelengths and the highest energy.

According to All About Vision, “Blue light is generally defined as visible light ranging from 380 to 500 nm. Blue light is sometimes further classified into blue-violet light (approximately 380 to 450 nm) and blue-turquoise light (approximately 450 to 500 nm).”

What does blue light accomplish?

Since it plays a role in establishing your “biological clock,” it exerts numerous diverse effects on physical and psychological processes – encompassing those that determine alertness, sleep, moods, motivation, memory, appetite, blood sugar regulation, and more.

Bright blue light operates by stimulating cells in the retina that are connected to the hypothalamus, a part of the brain that aids in controlling circadian rhythms and numerous metabolic/endocrine functions.

Where are you exposed to blue light?

In numerous scenarios, you are exposed to blue light, both when you are outdoors and indoors. As per the American Academy of Ophthalmology, the sources of blue light include:

• Sunlight, which serves as the primary source of this type of light. It is actually the scattering of blue light rays that causes a cloudless sky to appear blue on a sunny day.
• Fluorescent and LED bulbs, which contribute to lighting your home.
• Display screens of electronic devices, including computers, laptops, tablets/notebooks, and smartphones. Studies indicate that for the majority of people, the quantity of blue light received from screens is actually minuscule when compared to that from the sun.
• Light therapy boxes utilized to treat seasonal affective disorder. (There is also red light therapy, green light therapy, and sun lamp therapy.)

Effects of Blue Light on Sleep

Writers at Harvard Health Publishing inform us that, “Prior to the advent of artificial lighting, the sun was the predominant source of illumination, and people spent their evenings in (relative) darkness.”

Today, however, the majority of us are exposed to light (from devices and bulbs) right up until the moment we go to sleep.

How does blue light influence sleep?

It is now widely recognized that spending time on digital devices close to bedtime has the potential to disrupt your circadian rhythm, which helps determine when you feel sleepy or awake.

When your circadian rhythm is disrupted, you might become more prone to developing conditions such as diabetes, heart disease, and obesity.

There is evidence suggesting that high-energy light exposure at night (once it’s dark outside) suppresses the release of the hormone melatonin, which is the primary hormone influencing circadian rhythms and sleep cycles.

Lower melatonin levels can make it more challenging to fall asleep and stay asleep, and emerging studies now suggest that it might also be associated with other health issues.

How Blue Light Affects the Eyes

Why else is blue light detrimental to you?

One reason is that it tends to cause “eye strain.”

Staring at the screens of digital devices for extended periods causes the eyes to absorb a significant amount of unfocused light, leading to squinting, irritation, dryness of the eyes, difficulty in focusing, and what feels like eye fatigue. This is also known as computer vision syndrome.

Some experts are also concerned that frequent exposure to high-energy light might have potential long-term implications for eye health.

How can blue light cause eye damage?

Compared to UV light, human eyes are not nearly as proficient at blocking blue light. A very high percentage of visible blue light passes through the corneas and lenses of the eyes and reaches the retinas (the inner lining at the back of the eye).

This could potentially lead to damage to the retinas and changes in vision, including an increased risk of macular degeneration.

However, there is no concrete evidence indicating that blue light exposure elevates the risk of macular degeneration, and eye doctors do not seem overly concerned about it at present.

Researchers do note, though, that blue light-emitting devices are relatively new in the overall scheme, and more long-term studies are necessary to gain a deeper understanding of their effects.

Other Risks and Side Effects

Apart from concerns regarding eye damage, excessive blue light exposure at night is now linked to disruptions in circadian rhythms, and as mentioned earlier, this might pose a risk for problems such as:

• Blood sugar fluctuations
• Obesity/weight gain (due to alterations in the levels of leptin, a hormone contributing to a feeling of fullness)
• Diabetes
• Cardiovascular issues
• Depression
• Potentially even cancer
• Headaches

Are There Any Blue Light Benefits?

Blue light is not inherently evil and is, in fact, associated with certain benefits. While exposure at night can disrupt sleep, exposure during the day is actually crucial for regulating numerous bodily functions.

For instance, if you’re seeking ways to enhance memory, blue light might be able to assist.

Sunlight exposure, which is the number one means through which people are exposed to high-energy visible light, is necessary to maintain healthy vitamin D levels and also to regulate our circadian rhythms (the body’s natural wakefulness and sleep cycle) and moods.

Exposure to natural light outdoors has also been demonstrated to increase alertness, safeguard against depression (specifically seasonal affective disorder, a type of depression related to changes in seasons and a lack of sunlight), and aid in memory and other cognitive functions.

Because a regulated circadian rhythm is essential for obtaining restorative sleep, there are also associations between daytime blue light exposure and protection against obesity, diabetes, heart disease, and other conditions.

“Light therapy” boxes, which emit bright white and blue light rays, can assist in treating symptoms of seasonal affective disorder (SAD) such as fatigue, weight gain, and feelings of worthlessness. Some studies suggest that using light therapy boxes for approximately 30 minutes daily can even be as effective as antidepressant medications in treating SAD.

There is even some evidence that blue light exposure can enhance skin health. For example, research indicates it might help:

• Treat acne
• Improve actinic keratoses
• Alleviate psoriasis symptoms
• Potentially even combat skin cancer

How to Limit Exposure

1. Avoid electronic devices close to bedtime

Using your phone, watching TV in close proximity, and reading on a tablet before bedtime can disturb your internal clock, potentially resulting in sleepless nights and daytime fatigue. Experts recommend that you refrain from using electronics two to three hours before going to sleep, or at the very least, utilize only electronics that have blue light filters enabled.

It is also prudent to limit your proximity to screens during the day and the duration of time spent looking at them, especially up close without breaks.

2. Filter blue light with glasses and apps

If you wish to continue using electronics at night while safeguarding your eyes from blue light, the best option is to give blue light-blocking technology a try, including blue light glasses and settings on your computer/phone/tablet that filter light.

In recent years, an increasing number of filtering apps have become accessible for smartphones, tablets, and computer screens, preventing significant quantities of blue light from being emitted from these devices.

How do blue light glasses function? They contain a coating that blocks bright light wavelengths from reaching your eyes.

Some have amber or yellow-tinted lenses, and many are available without a prescription. They can also assist in increasing contrast when you’re working on devices for extended periods, which can enhance comfort and reduce eye strain.

Discuss with your doctor which type of glasses/lenses with filters will be most suitable for you. Currently, there are numerous options available depending on whether you typically wear lenses/glasses or not, such as:

• Single vision lenses that allow you to view a broader visual field, such as your entire computer screen.
• Glasses with special glare-reducing, anti-reflective coatings that block high-energy light from both the sun and devices.
• Photochromic lenses (or transitions), which block UV and blue light both indoors and outdoors.

Blue light filtering glasses and lenses might offer enhanced protection among individuals who have undergone cataract surgery, as they are even more susceptible to eye damage caused by excessive light exposure.

Shift workers and “night owls” who stay up late on certain nights can also reap significant benefits from the use of eyewear that blocks blue light if they aim to “reset” their circadian rhythms and fall asleep more effortlessly.

3. Get sunlight exposure during the daytime

Daytime sunlight exposure is vital for regulating your circadian rhythm, as it essentially sends a signal to your body that helps your brain distinguish between daytime and night time.

If possible, obtain some sun exposure within the first hour or so after waking up, such as going outside for 10 minutes or more. Strive to spend 30 minutes or more outdoors each day to ensure your eyes receive adequate light, or be certain to sit close to a window so that you at least perceive some light coming through.

Research suggests that sunlight exposure is also significant for the proper development of children’s eyes and vision. Insufficient exposure is believed to potentially contribute to myopia/nearsightedness, thus it is encouraged to have your children spend time outside each day.

4. Consider changing your light bulbs

While LED and fluorescent lights emit more blue light than the light bulbs of the past, there are now certain coatings that can be added to the inside of these bulbs to make them produce a warmer, less blue light. Red, warm light has a lesser impact on circadian rhythms and melatonin suppression.

Incandescent lights also produce some blue light, although less than most fluorescent light bulbs. You might not desire to use warmer lights throughout your entire home, but consider installing them in your bedroom or any other area where you spend time before going to sleep.

Other methods to limit blue light exposure include:

• Ensure overall support for your eyes, including wearing glasses with the correct prescription if necessary.
• Keep your eyes moist.
• Adopt the 20/20/20 strategy, which means pausing every 20 minutes to focus on objects that are 20 feet away for 20 seconds before returning to viewing your blue light screen.

Final Thoughts

• There are both advantages and disadvantages associated with blue light. Exposure during the day can lead to improved attention, reaction times, and moods, but exposure at night can disrupt sleep.
• Sources of this type of light include the sun, fluorescent and LED bulbs, and display screens of computers, electronic notebooks, smartphones, and other digital devices.
• Special blue light filtering glasses can be beneficial in reducing exposure from computers and other digital devices, particularly at night. It is also recommended that you avoid using electronics at least two hours before bedtime and obtain sunlight exposure during the day.