what are blue light blocking glasses

What Are Blue Light Blocking Glasses? 3 Reasons Blue Blockers Work

There’s no shortage of biohackers who adore blue blockers (including me). But what are blue light blocking glasses really? Today you’ll find out what blue light is, is blue light blocking is necessary, and a few pro tips to protect yourself from blue light, as well as use blue light to your advantage, to increase alertness.

What is Blue Light

Blue Light is a type of light with a shorter wavelength of around 450-500 nanometers that is visible to the human eye. But is blue light really that blue? Turns out LED bulbs and screen devices are all emitting blue light, so no it may not look so blue after all.

Science has discovered that blue light can have a significant effect on our health and well-being. By affecting our sleep and circadian rhythm, it already affects our energy metabolism, mitochondrial function, and hormone balance.

Before we go in-depth on blue light, let’s explore the spectrum of light, shall we?

Electromagnetic field, Pulsation, and Light

Energy moves, energy flows. Light is just one form of energy that we can visually see. Energy is transmitted, released, and showcased through pulsation. If you’ve ever heard of electromagnetic radiation (I wasn’t into physics back then, you can tell), it consists of electromagnetic field waves which propagate through space.

The shorter the wavelength of the light, the higher the effect on our system. Very short wavelengths like UV or ultraviolet and X-rays are known to be detrimental and dangerous for humans. On the other hand, the longer the wavelength, the less of an effect it has.

Blue light, as well as other shorter wavelengths, are energy-stimulating, while lights with longer wavelengths like infrared or red won’t make us alert, but they signify nighttime and can help us relax.

blue light glasses

The Wavelength of Different Light (UV, Blue, Yellow, Red)

These waves have specific lengths. In terms of light, it is known that there are shorter wavelengths like gamma rays or X-rays, then there are UV or ultraviolet rays (the sun, you already knew right) and then there are medium-length or visible wavelengths like blue, yellow, or red light. There are also wavelengths of 700 nanometers + we can’t see infrared light (that sauna thing), radar, or radio waves.

To better understand this classification, we’ve provided a table showing the wavelengths of specific rays, lights, or waves. Keep in mind, these classifications can slightly differ if you count in secondary colors like orange (between yellow and red) and cyan (between green and blue).

  • Gamma-rays: < 0.01 nm
  • X-rays: 0.01 – 10nm
  • Ultra Violet Light or UV: 100 – 400 nm
  • Violet: 400 – 450 nm
  • Blue: 450 – 500 nm
  • Yellow: 570 – 590 nm
  • Orange: 590 – 630 nm
  • Red: 620 – 750 nm
  • Infrared: 800 nm – 1mm
  • Radar: 1mm – 1m
  • Radio Waves: > 1m
Why are blue light-blocking glasses good?

Blue blockers can block blue light, which is beneficial at night, as overexposure to such light can cause sleep disturbances. Also, it may reduce digital eye strain and headaches, as well as prevent age-related macular degeneration.

Which blue light glasses should I get?

Getting blue-light glasses isn’t a simple task. Matter of fact, many cheap 5$ blue glasses won’t work, it’s just marketing. It takes more to make high-quality, yellow-tint, blue blockers. Consider checking out reputable brands or optics stores like NOOZ, RA Optics, TrueDark, and LensDirect.

Can Blue light-blocking glasses cause headaches?

For many people who aren’t used to wearing blue blockers, the first few days (as was the case with me) may cause eye strain. This is the adaptation phase for most first-time wearers. This is just acute and it will most likely resolve in a few days.

Optical Spectrum: The Only Light We Can See

Isn’t it weird we only have five senses, six if you count intuition? Imagine we had thousands of senses and could feel, see, taste, or do whatever other senses allow us to sense, more.

As creepy as it sounds, there are actually a ton of different lights we can’t see with our visual system. There are sounds that we can’t hear (both too loud, or too quiet). We only perceive the light and colors our visual system can process.

Therefore, it is interesting to see that we can only see lights of a certain wavelength. These lights are part of the so-called optical spectrum, the spectrum portion only visible to us. These wavelengths are in the range of 380 – 750 nanometers.

The 380 – 750 nanometer light is the wavelength we can see, so if you checked the table up there, we can only really see violet, blue, yellow, orange, and red light. What remains invisible are the shorter or longer wavelengths, like ultraviolet light, x-rays, infrared light, radio waves, etc.

How Blue Light Affects Our Sleep and Wake Cycle

The circadian rhythm is our internal clock which tells us when we are ready to relax and go to sleep (Zzz) or wake up, be alert, and focused. There are specific hormones secreted at specific times of the day which allow us to function the way we do. Imbalances in circadian rhythm cause imbalances in hormones which can have negative effects on health.

Fun Fact

At nighttime melatonin and serotonin are secreted, which allows us to tap into the rest-and-digest state. In the morning cortisol and adrenaline are secreted, which allows us to produce energy, start moving, and be focused.

The good news is, light is one of the major factors dictating or supporting our circadian rhythm. Our body adapts to light. This is quite natural, as when the sun goes up we can wake up and function at our best, but at night we need darkness to sleep well.

The problem these days is, the nighttime screen-staring we do, tricks our brain into thinking it is daytime, disrupting the secretion of melatonin. These devices mainly emit blue light.

Now blue light can stimulate the photosensitive retinal ganglion cells or ipRGCs in the retina of your eye, which by sending that information can increase your alertness, arousal, and focus. This sends a message to your system, that it’s daytime, promoting wakefulness instead of sleep.

Alertness vs. Sleepiness | How to Hack Blue Light

Blue light can have its pros and cons. From one perspective it activates our systems and enables us to completely wake up. From another perspective, it can disrupt sleep patterns and circadian rhythm which has detrimental health effects. Learning to properly time blue light during the day can enhance your sleep, alertness, cognitive function, etc.

Promoting wakefulness is probably the biggest pro of blue light. Without blue light, we can’t function optimally (or at all for that matter). The sun emits blue light, hence why rolling up your shades in the morning is beneficial, when you initially consume (see) light first thing in the morning.

The bad side of blue light is the dark side, or what I like to call “the night side”. At night, especially 2 hours prior to sleep blue light can disrupt your sleep cycle. By exposing yourself to blue lights, aka staring at a computer screen or mobile devices you trick your body into thinking that it’s daytime, and it will keep you awake, making it hard to fall asleep.

So, nighttime blue light exposure leads to poor sleep quality, waking up or less REM, or deep sleep at night. This is the time we want to block it or limit our exposure to blue light.

Pro Tip

At night before going to bed, consider dimming the lights in your home, switching the monitor or mobile screen to night mode (orange to yellow-ish tones), and put on your blue light-blocking glasses, not just to look like a biohacker, but to block blue light.

Are blue light-blocking glasses effective/worth it?

Blue blockers are definitely worth it, as we can find decent glasses for around 100$. Potential age-related macular degeneration, improved focus, deeper sleep and reduced eye strain seem worth to me. They are effective if you wear (use) them at the right time, and have high-quality ones.

Will blue-light-blocking glasses help with headaches and eye strain?

Contrary to our beliefs, blue blockers won’t have a profound effect on eye strain, because digital eye strain originates from close screen staring, ocular muscle fatigue and dry eyes (due to not blinking enough). Research shows that blue blockers may help with headaches in people with light-sensitivity-related migraines, because they block the blue stimulating light, and reduce brightness or contrast (darker shade).

Do blue light glasses without yellow tint work?

According to an ophthalmologists, yes. Although they look fancy, and the amber (orange-yellowish) shade can aid in more optimal (dimmed, natural) night-time colors, to block blue light, yellow-tint isn’t a necessity. They’ve done blue light testing and it seems that high-quality blue blockers although completely transparent, can block longer wavelengths of blue light more effectively, than red, orange or amber-looking 5$ glasses.

The Cons of Blue Light Exposure

It seems that blue light isn’t that bad after all, huh? However, blue light exposure at the wrong time can hinder your sleep, reduce sleep quality and time spent in deep sleep. The side effects? You don’t want to mess with your sleep, as poor sleep is linked to mitochondrial dysfunction, slower metabolism, higher risk of cardiovascular diseases, diabesity,… you get the point.

Here are some of the research-backed potential negative side effects of exposure to blue light at the wrong time (night) and some associations of disease risk.

  • Higher cancer risk – linked with artificial light (or blue light) exposure at night during nighttime shifts, which causes circadian rhythm disruptions. (1)
  • Higher risk of obesity – sleeping with artificial lights aka TV’s on during the night was highly associated with gaining more weight and incident obesity. (2)
  • Higher risk for cardiovascular diseases – sleep deprivation and an overactive sympathetic nervous system is associated with a higher risk for coronary heart diseases and hypertension. (3)

How Do Blue Light Blocking Glasses Work?

If you still haven’t figured it out, blue-blocking glasses do exactly what their name suggests, block blue light. Now, the quality of the glasses will dictate how effectively they block blue light, and to what degree. It’s definitely one of the key ways to optimize sleep.

Research shows that suppression of blue light at night time can be effective in keeping/maintaining stable metabolism and circadian rhythms. And as we saw earlier, there is a strong relation between circadian rhythm and sleep quality, and the importance of sleep for our health. (4)

3 Reasons Blue Blockers Work

1. Improve the Duration and Quality of Your Sleep

The primary reason blue-light-blocking glasses work is by improving sleep. This can have numerous effects on our health, from metabolism to energy creation and hormone balance and regeneration.

A systematic review published in 2021 shows that blue-blocking glasses have been used for mood and sleep improvement. BB glasses reportedly improved sleep by increasing melatonin secretion, as they reduce the blue light which activates our photosensitive receptors, telling our body to stay awake. Both in patients with sleep disorders, variable shifts, and jet lag, people were able to reduce sleep onset latency with blue-blocking glasses. (5)

2. Potential To Reduce The Risk of Developing Age-Related Macular Degeneration (AMD)

It’s fair to say that many of us believe staring at screens can speed up vision loss. It turns out science isn’t so clear about that, but it is clear that it will cause eye strain. There are many factors related to vision loss and macular degeneration, and blue light isn’t the strongest one, contrary to our beliefs.

Macular degeneration comes with age, as our macula deteriorates, we have fewer light-sensitive cells which results in poor central vision. (6)

Wearing blue blockers may aid in AMD prevention as they can reduce eye strain and dryness, which may facilitate macular degeneration. It seems as if the most critical wavelength of blue light is between 415 to 455 nanometers. This means wearing blue blockers that block specifically this, or all blue wavelength ranges can be beneficial.

Also, blocking all blue light will probably distort the color, making it slightly more yellowish-to-orange, hence why the biohacking glasses have that amber color. (7)

3. Reduce eye strain and headaches (For people with migraine-related light sensitivity)

The data on alleviating digital eye strain is pretty controversial. There are many studies showing that blue blockers or blue-blocking lenses for that matter have no profound effect on reducing eye strain, as the main problem doesn’t lie in blue light. (8) (9)

Most digital eye strain problems like headaches, dry eyes, eye fatigue, or ocular muscle fatigue come from staring at a screen for a long-duration, not blinking enough, and being too close to your screen. Blue light isn’t found to be a strong contributing factor for headaches or digital eye strain, yet.

However, in people with light sensitivity who experience migraines or strong headaches, dimming the screen lights to night mode, or orange shade, and reducing brightness or contrast can significantly help. (10)

This is exactly what some blue blockers can do, reduce the stimulation of photosensitive receptors as less blue light is received, thus resulting in lower stimulation. Plus many glasses have an amber color with a darker tone which reduces the overall light on the eye, which along with high contrast are some of the main reasons people experience headaches.


  • Blue light is a type of light with a wavelength of 450 – 500 nanometers. It is emitted by the sun (the richest source of BL), by LED lights, fluorescent lights, and electronic devices. It has a profound effect on our sleep and metabolism.
  • Blue light exposure in the morning is optimal (roll your shades) as it promotes alertness, focus, and wakefulness.
  • Blue light at nighttime leads to sleep disruption and lower sleep quality which is associated with many neurodegenerative, chronic, and cardiovascular diseases.
  • Blocking or limiting blue light, especially at night can be beneficial for our health, potentially reduce eye strain, headaches, and reduce the risk of macular degeneration. Plus, it improves our sleep.
  • The best way to do it is by investing in Blue blockers, or blue-blocking glasses, and wearing them at night if exposed to screen devices or blue light.

Frequently Asked Questions

Can Blue light-blocking glasses cause or prevent headaches?

Yes, blue light blockers can potentially prevent headaches. Research is limited, showing only in people with light-sensitive migraines, blue blockers can significantly help. Otherwise, contrary to our beliefs, blue light isn’t the main cause of digital eye strain, but dry eyes and ocular muscle fatigue, with which blue blockers won’t help.

Can blue light glasses help you sleep better?

The biggest pro of wearing blue blockers at night is improving sleep. Matter of fact, the nighttime devices or screens you’re using are tricking your brain into thinking it should stay alert as in the daytime. Blue blockers block the light that causes this (blue light, you guessed it). By doing so, it allows for stable circadian rhythm, improved sleep, and proper melatonin secretion.

When to wear blue light-blocking glasses?

Blue blocking glasses are effective and have the potential positive effects if we wear them at night. Many people start their day with blue blockers, which isn’t optimal. Blocking blue light in the morning and during the midday can make us sleepy, non-focused and give our body a signal to start secreting melatonin. The best use of Blue blockers is 2-4 hours before sleep, at nighttime, especially if you’re in a very well lit (illuminated) environment, or at home looking at screens.

Similar Posts