Lighting the Day as the Day is!

Lots of us are up at all sorts of hours. Our days get turned topsy-turvy because, since we now all work all day as we can work anywhere, we get a call from a colleague on another continent at 3 am (sometimes the apologies for these calls are a lot more heartfelt and apparently sincere than other times). Or a baby decides it has nothing better to do at 2 am than to cry and cry and cry. Or we formally agree to work through the night, taking our turn covering patient care between dusk and dawn, or we (surprise!) find ourselves needing to keep working away (occasionally this is actually a good thing, maybe we get on a role as we do our taxes or write the conclusion to our novel and decide to keep plowing away until things are done).

For all of these potential reasons, and many more, it’s great if the places where we spend our time have some sort of circadian lighting. Circadian lighting (described in technical detail here and at articles linked at this website: https://www.gsa.gov/governmentwide-initiatives/federal-highperformance-green-buildings/resource-library/health/circadian-light-for-your-health) is artificial light that mimics the sort of natural light that’ll be present outdoors at any time. When the artificial light we’re experiencing and the natural light around us align our biological systems function most effectively, which helps us feel better physically and be less stressed mentally, all of which is very important.

Obviously, light we experience at any time has to also be consistent with the activity planned, if you need to remove someone’s appendix at 3 am, the light in the operating room has to be just as bright as if you were removing that appendix at 3 pm – but the light you experience after that operation is done, as you decompress, for example, doesn’t have to be.

Also, to develop your own circadian lighting system you don’t need to purchase the, often expensive, options on the market particularly labelled as circadian lighting. You can put your own systems together by outfitting some light fixtures with bulbs that emit cool light and others with warmer light bulbs. The packaging on the light bulbs you buy will tell you if the light to be emitted is cool or warm. To get the most bang for your circadian buck, it’s best if the cool light bulbs are in overhead fixtures and the warmer ones are in table top or floor lamp ones (in nature we’ll experience cool light from the sun when it’s higher overhead and warmer light when the sun’s setting and it’s time for our days to wind down).

Use only one colour of light at a time.

Turn on those cool overhead lights in the mornings and afternoons (except if you’re going through a period of late night shifts, your sleep is much better in darkness than when any lights are on). If you’re working late shifts and need to sleep during the day, ape the light outside when you wake up, whatever it is. Cool light in the morning is particularly good at helping you wake up and think clearly, but starting off with a brief period of dimmer, warm light, say before 8 am if you work mainly 9 to 5, is OK.

Turn on the warmer light (which ideally is also a little dimmer), as dusk starts.

It is true that looking at the sort of blue light that usually comes from devices such as iPads will keep you awake, so after dark use your devices with their night mode setting.

We should all sleep in the dark, and curtains/blinds/etc. should be used to help you sleep in a space that’s as dark as it reasonably can be.

Many of us like the security of night lights, to help us travel to a bathroom if we wake up in the night, for example. To be least disruptive, those night lights should emit amber or reddish light.

Coordinating the light you experience inside, with the light that’s outside, helps keep both your brain and body happy, healthy, and doing their best work.