They say that the eyes are the windows to the soul. Maybe that’s true. What the soul is and where it resides, I have no clue.
What I do know is that the eyes are most definitely the windows to the brain. In fact they are the brain.
That’s right, the eyes are a physiological extension of the brain, the only part of the brain to exist outside of the cranium. Crazy right?
And the eyes do so much more than just allowing us to see.
One of the important roles of the eyes is in the interaction of our biological system and light, in particular, sunlight.
As detached as many of us are in the industrialised world from nature, we still, at our core, are part of the natural ecosystem. We are designed to live in harmony (think Avatar rather than Snow White) with the natural ebb and flow; the cyclic rhythms of our planet hurtling through space.
Every single cell in your body works with the natural 24 clock of the solar day. Some cells are working at night, some during the day, but all are working on the same 24 hour clock.
The way our internal clock is naturally set is primarily down to how we view light. We do this via the eyes.
For our ancestors this was easy. The sun would rise, we would wake and go about our business, the sun would set and we’d go to sleep. Job done.
This pattern put into play a set of mental, physical and behavioural changes that follows a 24 hour cycle – the circadian rhythm. This circadian rhythm is common to most living things, including animals, plants and microbes. And, of course, you!
But now, shoot forward to our modern, industrialised lifestyles and we have thrown the spanner of all spanners into the cogs of the circadian rhythm.
Inconsistent shift work patterns, artificial light, shifting time zones and seasonal clocks, stimulants of every kind, dietary patterns that jack up our systems at the wrong time, and epidemic levels of stress, all act like dirt and grime in the intricate cogs and springs of our internal clocks.
Disrupting this circadian rhythm will eventually cause our already wobbly wheels to fall off. Poor metabolism, dysfunctional immune systems, and deteriorating mental health are just a few of the issues that can arise.
But the fix is fairly simple and free.
Seek the light.
Exposing the eyes to light, ideally sunlight, within an hour (preferably sooner) of waking will be one of the biggest resets you can do.
This works for us regardless of the time we wake, but will have greatest benefits closest to sunrise.
When the sun rises it emits infra and near infra-red light, longwave light spectrums that have a myriad beneficial uses. It also emits blue light in a number of forms including UVA and UVB.
Blue light gets a lot of bad attention, and for good reason. Blue light radiation later in the day is thought to be a major disrupter of sleep patterns. Too much exposure to blue light may cause macular degeneration of the eyes, and UV B is directly linked to skin cancers.
However, as always the difference between medicine and poison is in the dosage.
Lack of blue light in the morning (or upon waking) is also a bad idea.
When the blue light radiation from the rising sun hits our eyelids, that light filters through to the optic nerve. From here it passes into the pineal gland at the centre of the brain. This gland sends out the neurotransmitter serotonin, the ‘feel good hormone’. Serotonin helps with mood, hunger sensations, as well as the modulation of melatonin, which we’ll discuss shortly.
The brain then releases cortisol, the stress hormone. Again this is vital for optimal health, only becoming problematic when levels become chronic. It’s cortisol that ramps us up and get us ready to move and face the day.
To enhance this effect getting up and looking towards the morning sun really helps. At the back of the eye, in the lower section we have photosensitive retinal ganglion cells (There is a test paper at the end of this article!). These cells are particularly sensitive to light in the blue spectrum, so are perfect for activating a whole host of biological chain reactions that help re-set of circadian rhythm.
‘Can I just look at my phone instead. That’s blue light isn’t it?’
Whilst it’s true that phone and computer screens emit blue light it’s not nearly powerful enough to set up the cascade of benefits (the opposite is true in the evening though!). The amount of photon energy delivered by the sun is ample though, even on cloudy days.
But you need to be directly in the light. Looking at the sunlight through a window won’t cut it sadly. The glass actually filters out the UV B needed for this, as would wearing sunglasses.
Going outside has become one of my morning practices. If you don’t want to, or can’t get outside, then opening a window or the door and viewing the light from the inside the house is fine. Sometimes I sit with the front door open, watching the morning sky from a cushion in my hallway.
Maybe this is why so many cultures have the doorway to their dwellings facing the rising sun.
Between 2-10 minutes of light viewing is all it takes.
And it should go without saying that the aim here is not to burn out our retinas. You do not have to, nor should, stare directly at the sun, just into the direction of it.
Amazingly this can also work for many blind people too. If the eye is present, even if sight is absent, it can often still be sensitive to light exposure.
I must admit, I do love my blue blocking glasses. In fact I have an embarrassingly large amount of them. And while they do make me look rather dashing, wearing them first thing in the day is not a good idea. Remember we are welcoming the morning blue light into our eyes. Keep the blue blockers for the evenings.
Now, if you live in the extreme latitudes then you may not get sufficient photon exposure at certain times of the year. If this is the case you can use an artificial daylight simulator instead.
I’ve talked previously about the importance of getting sunlight on the skin for things such as the production of vitamin D (see here) and the activation of the P53 gene that helps with healthy cell production and the prevention of cancer.
Interestingly, it seems that when the P53 gene is activated by UV B light it can actually increase sexual desire. Maybe that’s why we feel a bit fruitier on those sunny holidays.
What about later in the day?
Good photon exposure throughout the day is helpful. Again, we are being dose conscious. Whilst UV B has many benefits, too much exposure is damaging; our skin burns and damage can be severe and lead to skin cancers.
But as the day starts to turn to evening we also need to change our tactic.
Viewing the evening sunset is not only lovely and romantic (especially if the libido is up from all that earlier exposure) but it also helps with the recalibration of our internal clock.
At this point the light from the sun at these lower solar angles has again become those longer wavelengths, the yellows, orange and reds.
These hues help with the timed release of melatonin, the drowsy/sleepy hormone, in the process known as Dim Light Melatonin Onset (DLMO) and it’s this mechanism that makes us feel sleepy.
Remember, we need that early morning serotonin in order to modulate the production of melatonin, but bright blue light later in the day will actually stop the flow of melatonin. In fact intense light of any colour can inhibit it. This has been shown to affect mood quite considerably.
So as the sun sets you want to reduce the amount of blue light you are looking at. You can do this through the use of blue filters on electrical devices, blue blocking glasses, and colour changing bulbs
See this article here where I give you more tips on optimising sleep.
The benefit of modern colour changing lightbulbs is that they are usually dimmable too. Reducing the intensity of the light in the evenings is key. Dim the lights or switch them off entirely and go oldskool with candles, as these are working in those DLMO inducing yellow/orange/red tones.
Another thing to consider is light placement. Remember how we discussed those cells in the eye being in the lower part of the eye. They are placed there to better take in the light from overhead.
So if we don’t want to trigger this system off in the evening it’s better to have light lower down. Think table lamps, candles and floor lighting. This is where a low plug-in night light can be great for those middle of the night toilet trips rather than the shock of bright overhead lighting.
Although our circadian rhythm is based around the 24 hour solar day, our biology is also wired to the yearly cycle too. This is known as the circannual rhythm.
As the days grow shorter in the winter, so our bodies typically produce more melatonin. As the days grow longer we are exposed to more light which reduces melatonin production. This natural, undulating pulse of melatonin is important for optimal health.
Unfortunately, our modern lifestyles do not cater for this kind of seasonality, every day being the same regardless of the time of year. This has long been a grumble from all here at Wild Life HQ. We like to go hard, work-wise, in the summer, but slow down and get cosy in the winter months.
Daily sun exposure, in particular the rising and setting, really helps to rectify this, and with the latitudes we live at, this becomes increasingly easier as the year turns towards winter. Come mid winter the sun rises just before 9am and sets by 4pm. Easily observable by all but the most nocturnal of night-owls.
So regardless of your schedule, it should be possible to hack your lighting situation to try and bring you back to some kind of natural cycle, it just takes a little forethought and mindfulness.
If you take one thing from this it should be to make a morning sunlight observation part of your daily practice. Trust me, it’ll make a big difference.