Blue Light, The Outdoors & Sunlight

As you step outdoors into the sunlight, the human eye is exposed instantly to several visible and invisible light spectrum’s. Blue light and UV light is the most known of these spectrums; they enter our body through the eyes and skin. Initiating chemical reactions in our bodies both inside and outside. A well-known example from UV light is sunburn.Sunlight Outdoors On The Beach. Sunlight & Blue LightSunlight is part of the human race and has been for millions of years, like most animals on planet Earth. It plays an essential role in our survivability as well as being a major contributing factor in the global ecosystem. Sunlight synchronises human and animal sleep cycles known as the circadian rhythm. It’s linked to every part of us, our metabolism, alertness even our mood and mental state. Have you had a stressful day? A short walk in the park or spending time outdoors can completely change how you think and feel, and this is partly due to sunlight.

Blue Light, Sunlight & The Light Spectrum

Many of us do not realise the light emitted by our sun has all the colours of the rainbow. Each colour has a different amount of energy and capability to impact us as humans. Sunlight contains a range of colours, red, orange, yellow, green and blue light, each of these with their specific energy and wavelength (called electromagnetic radiation). When we combine all these colours, we get “sunlight” or “white light”.

Sunlight, The Outdoors, Visible and Invisible Light

Science has proven that the colour we see (or cannot see) links to the wavelength, and this is linked to the amount of energy each colour contains. Long wavelengths, such as those found in the colour Red, has less energy while Blue’s which have shorter wavelengths have more energy. So while we are all cautious about UV light and its damaging effects on our skin and eyes, it sits back to back with Blue Light.

We hope this article clears up where Blue Light sits on the light spectrum. If you want to read more about the damaging effects of blue light, please follow this link: Is Blue Light Dangerous.

Blue Light Blocking Glasses & Sleep

Before the invention of light bulbs, the human circadian rhythm was entirely in sync with the sun because night time light disruption was minimal. At night, exposure to devices emitting blue light is harmful to sleep and the circadian rhythm (the body’s biological clock). Research has proven that Blue Light prevents body temperature from dropping during the night. A slowly decreasing body temperature is a critical process to which the body progresses into the stage of sleep. Blue light keeps the body temperature elevated at day time levels.

Girl unable to sleep at 4am

Studies show that exposure to blue light, even when dim, can suppress the creation of melatonin. This hormone assists in controlling our circadian rhythms. A minuscule eight lux, the level of brightness well exceeded by desk and table lamps, and about twice that of a night light cause disruptions. Light from fluorescent bulbs and LED lights will also produce the same effect.

 

Blue Light, Sleep & Melatonin

The pineal gland in the brain is responsible for releasing melatonin, and it does so for a few hours before you start feeling tired. Melatonin level reaches its peak in the middle of the night.

Falling Asleep On The Lounge

Reading on a blue light-emitting device like a tablet instead of a printed book at night will take you longer to fall asleep due to the lack of melatonin produced. Essentially, blue light is a stimulant which sends a signal to your brain, tricking it into believing its day time, and you should be awake. Research has identified that people exposed to blue light at night tend to have less REM sleep; this is when when dreams occur. Less REM sleep results in tiredness in the morning, even after a full eight hours of shuteye.

 

Stephen Lockley, a Harvard sleep researcher, stated that light at night is part of the reason so many people don’t get enough sleep. The idea that blue light is so problematic is that it has a short wavelength that affects levels of melatonin more than any other wavelength does.

Dr Charles Czeisler of Harvard Medical School identified in 1981 that daylight is the mechanism that keeps a person awake. The outside world runs our sleep schedule, so it makes sense that less blue light at night, can help regulate your biological clock.

Wearing blue light blocking glasses at night will contribute to the elimination of sleep and circadian rhythm issues by preventing blue light from reaching your retinas.

References

Blue Light (High-Energy Visible) and Blue Light Blocking Glasses

The eye’s cornea and lens are unable to filter or deflect Blue Light.

Photochemically-induced retinal injury is caused by the absorption of light by photoreceptors in the retina. Photoreceptors such as rod cells, cone cells & photosensitive ganglion cells convert light into electrical signals in the eye. Normally, when light hits a photoreceptor, the cell bleaches and becomes ineffectual until it has recovered through a metabolic process called Wald’s visual cycle. This visual cycle is the biological process which converts photons, such as electromagnetic radiation (UV light & Blue Light) into electrical signals in the retina.

When the retina is constantly and repetitively subjected to the presence and absorption of Blue Light, at a wavelength 400 – 500 nm, rod cells & cone cells become unbleached and responsive again to light before they are ready.

A few minutes of exposure to Blue Light at 408nm is enough to cause permanent death of photoreceptors and lesions of the retinal pigment epithelium.

Blue Light, Eye & Vision Damage

 

Now let’s compare wavelengths…

    • Blue Light (HEV) versus Ultra Violet A, B & C
    • UV-C (100 nanometres to 280 nanometres)
    • UV-B (280 nanometres to 315 nanometres)
    • UV-A (315 nanometres to 400 nanometres)
    • Blue Light (400 nanomatres to 500 nanometres)

What does this mean?

At a wave length between 400 – 500 nm, Blue Light passes through the cornea and lens and reaches the retina.

 

What are some of the known side effects of being exposed to Blue Light?

    • Cataract formation (also caused by long term exposure to UV light)
    • Age-related Macular Degeneration, the leading cause of low vision & complete vision loss
    • Night Blindness (also caused by lack of vitamin A)
    • Computer Vision Syndrome
    • Sleep deprivation / insomnia
    • Depression
    • Immune system suppression
    • Unstable moods / mood swings

Did you know…

    • Children’s eyes absorb more Blue Light than an adults, therefore children are at higher risk of sustaining vision impairment from exposure to Blue Light from digital devices

What are some known devices that emit Blue light?

    • LED lights (even in indirect presence, such as lightbulbs)
    • LED screens / TVs
    • Compact fluorescent lights
    • PC/laptop monitors
    • Smart phones / tablets

What can you do to prevent vision impairment and detrimental health issues contributed by Blue Light exposure?

    • Buy Blue Light Blocking Glasses.

Is Blue Light Linked To Cancer & Other Diseases?

Studies that can be found linked at the bottom of this page display a link between exposure to blue light at night, such as working the night shift, to types of cancer, diabetes, heart disease, and obesity. We also know that exposure to blue light suppresses the creation of melatonin, a hormone that assists with controlling our circadian rhythms, and there’s some preliminary studies that suggest lower melatonin levels might explain the association with cancer and other diseases.

That’s not all. A Harvard study identified preliminary results that link blue light to diabetes and possibly obesity. The researchers put 10 people on a schedule that gradually shifted the timing of their circadian rhythms similar to what occurs when you look at a screen or mobile phone. The test subjects blood sugar levels increased, placing them into a pre-diabetic state, and their levels of leptin, a hormone that keeps people feeling full after a meal, went down.

 

 

Furthermore, studies show that even dim light can interfere with your circadian rhythm and melatonin creation. A miniscule eight lux—the level of brightness well exceeded by most desk and table lamps and about twice that of a night light has an effect.

Stephen Lockley a Harvard sleep researcher made comment that light at night is part of the reason so many people don’t get enough sleep. Researchers have linked poor sleep patterns and lack of sleep to an increased risk for depression, as well as diabetes and cardiovascular problems.

 

Supporting Research

Blue Light Blocking Glasses & Biological Clock or Circadian Rhythm

Do Blue Light Blocking Glasses Help With Your Biological Clock & Circadian Rythm? Thats a question we get asked every all the time. Everyone has a different circadian rhythms, the typical length is around 24 hours. Those of us who stay up late (night owls) is slightly longer than 24 hours, while the rhythm of early birds is shorter, under 24 hours.

Do Blue Light Blocking Glasses Help With Your Biological Clock & Circadian Rhythm?

Dr. Charles Czeisler of Harvard Medical School identified in 1981 that daylight is the mechanism that keeps a person wake and sleep schedule synchronised with the outside world so it makes sense that less blue light at night, can help regulate your biological clock. So the answer is yes, Blue Light Blocking Glasses can help. If you would like to see what Blue Light Blocking Glasses we have in stock, please visit our shop.

 

What Are Blue Light Blocking Glasses? & What Is Blue Light?

Not every colour of light is the same. The blue wavelength is great during the day as it increases attention, improves reaction times, and lifts mood but it is the most troublesome wavelength at night. Many of us are surrounded by screens everywhere, from the second we leave for work, school, in the car to the last minutes of awake time before (trying) to go to sleep. This makes blue light very difficult to escape.

Blue Light – Not Every Colour  Of Light Is The Same

 

 

Do We Need Blue Light Blocking Glasses? & Is Blue Light Safe?

Do we actually need Blue Light Blocking Glasses or is it a myth? Well the studies and evidence suggests yes, everyone requires Blue light Blocking Glasses.

Blue Light is mostly friendly, we say ‘mostly friendly’ as it has not been around long enough for centuries of research and we are only now noticing its somewhat of an indirect, silent assassin. It can affect your sleep and this can potentially flow on to cause diseases. Until the invention of man-made lighting, the sun was the major source of light, and people spent their afternoons in almost darkness. Now, in much of the world, afternoons are as bright as day, you can thank Thomas Edison for inventing the light bulb.

Blue Light – The Silent Assassin

Do We Need Blue Light Blocking Glasses? & Is Blue Light Safe?

 

But, is all this light a double-edged sword? Is the human eyes, brain and body built for 14-16 hours of light? In the afternoon light alters the body’s biological clock otherwise known as the circadian rhythm, the effect is difficulty sleeping or poor sleep. We are slowly identifying through research that blue light may contribute to the causation of cancer, diabetes, heart disease, obesity and that’s not all. Poor sleep and blue light have been linked to moods, productivity, ability to handle life’s simple problems and there is a strong link to poor sleep and depression.

 

Do We Need Blue Light Blocking Glasses? & Is Blue Light Safe?