Why Light Matters


When it gets dark, you put the lights on and when you go outside in the day, you put your shades on, just like everybody else. Why?

Because we live in a civilized society and that’s the way things are done. At night, we have all this electricity for goodness sake and we can light up the darkness like a Christmas tree in full season, plus we all know that the sun is dangerous so you have to protect those precious eyes from its harmful rays, right?

Wrong, unfortunately. We can’t outwit, outplay and outlast nature, no matter how sophisticated and technologically advanced we think we are. Do we really think we can turn day into night and night into day without at least a few negative consequences?

Light is way more important to our health than you might imagine. Light is information, light is energy and light is a nutrient but light can also be toxic and disruptive.

It all depends on the quality of the light and how and when you use it. Light is one of those very rare things that can be described as agathokakological – from the Ancient Greek agathos for good and kakos for bad.

So light is really a mixed blessing, the curate’s egg of the universe – good in parts. It has a bit of a split personality – when it’s good, it’s very, very good, but when it’s bad, it’s horrid.

The trick is to know when it’s one or the other and here lies our dilemma. You see, if we follow the conventional wisdom of donning sunglasses, slathering ourselves with toxic chemical sunscreens and avoiding the sun at midday, we miss out on its healing properties. We also absorb the ridiculous notion that the sun is bad and ignore the very real dangers of artificial lighting.

Singing the Blues

The main problem is blue light, to which our eyes are particularly receptive. Almost all visible blue light (HEV or high energy visible light) goes right through the cornea and lens and travelsto the back of the eyeball and the light-sensitive retina.Structures in the eye protect this sensitive organ from UV light however and less than one percent of this makes it to the retina, sunglasses or not.

If this sounds like a design flaw, it isn’t, because nature’s got you covered.

During the day time, when the big ‘ol sun is shining in the sky, it’s the main source of blue light. This is when exposure to this high-energy light is important for health. It makes you feel more alert, brightens your mood and has a positive effect on your memory and cognitive function.

You might have heard of SAD, aka seasonal affective disorder, which is a form of depression that strikes when there isn’t enough light around in winter and lifts when spring and summer roll around.

As mentioned before, light is a nutrient and an energy source. InLight: Medicine of the Future, Dr. Jacob Liberman says, “…the human body is truly a living photocell that is energized by the sun’s light, the nutrient of humankind.”

The food you put in your mouth is eventually converted into ATP, known as the energy currency of life because it powers our cells. What most people don’t know is that light absorbed by our tissues is also converted to ATP. Not just any light mind you but the full spectrum light from the sun, which is free.

Regular exposure to sunlight oxygenates the blood, is an antidepressant and antimicrobial. It can help lower blood pressure and blood sugar, boost the immune system and balance hormones. All these things are independent of the benefits of vitamin D production in the skin.

Speaking of vitamin D, the only time you can produce it in your skin is when UVB rays are out – when the sun is high in the sky, which is exactly the time that you are advised to stay out of the sun. And God forbid you get a tan because, apparently, that’s nothing more than a burn. Pfft.

Thankfully, there are some sane minds who disagree with this notion, like Dr. Sam Shuster, Emeritus Professor of Dermatology at the University of Newcastle Upon Tyne. He calls a tan “nature’s own sun block”. He goes on to say, “The dogma, now fossilised in print, is that any tan is a sign of skin damage.

Tell that to Darwin. Pigmented melanocytes in the skin are a system that protects it from excessive UV, which evolved long before the advent of sunscreens. Even if there was hard evidence that melanoma was UV-induced it would be all the more important to keep a protective tan.” In other words, your best protection against sunburn is … a tan.


Be Afraid, Very Afraid

Now that we have the sun phobia out of the way, let’s deal with what we should be paying more attention to and that’s light at night.

Our ancestors only had fire or candle light after dark, both supplying warm light which didn’t mess with our biology. The closest we have to this is the incandescent light bulb, sadly now almost extinct.

These bulbs have been replaced with cold light or non-thermal light sources that emit the high energy visual light known as blue light. When blue light is mixed with the longer wavelengths, as in sunlight, fire, candle light and incandescents, it’s not much of a problem, but when it is isolated, it is a problem.

Think fluorescents, LEDs, flat-screen televisions, computer screens, electronic notebooks, smartphones and any amount of other digital devices that we stare at night after night.

There’s a triple whammy here. For starters, the light is entirely fake and therefore foreign to our make-up. Secondly, it is beaming into our sensitive eyes at night, at a time when we haven’t evolved to deal with it. Thirdly, it flickers but you just don’t notice it.

As high energy light, blue light generates reactive oxygen species, aka oxidative stress, in our tissues. When it is quarantinedfrom the regenerative long wavelengths of the red and near-infrared spectrum found in natural light, it is like the typical teenager left alone at home for the weekend without parental control – free to cause unrestricted damage.

And it does. It messes with the hormone melatonin – the one that tells your body it’s time to sleep. This means that it disrupts your sleep pattern by throwing your natural circadian rhythm out – hello insomnia and other sleep disorders, along with daytime fatigue.

All this, in turn, interferes with your mental health, and has nasty consequences for your endocrine system. It also negatively affects your retinal health.

Additionally, when your body clock is chaotic, of course your whole system is out of whack. It’s no surprise then that exposure to man-made blue light at nightcan contributes to blood sugar problems, depression, cardiovascular disease and even cancer. The constant flickering of this faux light also causes eye strain and can trigger migraines. In a word, it’s bad.


What to do?

During the day, get some exposure to natural sunlight, without sunglasses and windows to filter it.

At night, you could go back to the stone-age and ditch your digital devices and light bulbs altogether, but we all know that’s not going to happen.

The next best thing is to get some reverse sunglasses in the way of blue blockers. Spektrum Glasses (www.spektrumglasses.com) have an awesome range that offers various styles with either 50% or 99% blue blocking capabilities.

You can also get rid of the television (who needs one anyway?), find light bulbs that are kinder to your eyes, install blue light filtering apps on your smart phone, tablet and computer and use candle light every now and then. It might improve your love life too. Think of the romance.

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